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Our Boiler needs replacing and I am looking at alternatives. Has anyone installed alternatives to the Gas Combi boiler? I was looking at the Baxi Ecogen which also generates electricity which can be fed back to the National Grid - has anyone got one of these?
In reply to James Moyle: The hotel at the end of the road has a wood chip boiler- it feeds in dried wood chip via an auger/Archimedes screw arrangement. The system they use was supplied by the wood chip supplier, so well tied in. It takes up a lot of space though.
In reply to James Moyle: Worth looking at an air source heat pump maybe? They use electricity to power the compressor, but are omething like 250% efficient (i.e you get 2.5 times the Kw out in heat production as you do per KW electricity put in) as opposed to 97 odd percent for gas boilers.
Problems are that they run at a lower tepmperaure so you may need larger radiators. Also they arent as cheap as mains gas at the moent (defintely better than oil or lpg).
Work best when coupled with a solar pv installation on a feed in tarriff to offset the increased electricity costs.
Level of investment will depend on how long you plan on staying in the house versus payback period.
Problems are that they run at a lower tepmperaure so you may need larger radiators. Also they arent as cheap as mains gas at the moent (defintely better than oil or lpg).
Work best when coupled with a solar pv installation on a feed in tarriff to offset the increased electricity costs.
Level of investment will depend on how long you plan on staying in the house versus payback period.
In reply to peterjb: Thanks for this one - worth looking in to.
In reply to peterjb:
Why? please explain
??????????????
Solar PV in the UK is a joke; average solar radiaion in the UK is 912 kWH/m2 per year,solar PV is 10% efficient, ie 91 kWh/m2 (extremely expensive panels are 30% efficient; handy for NASA). You would need approx 100m2 of solar panels to give you an average of 1 kW, 2.5 kW output from your air source heat pump, cost only £60K for the panels. Of course you would het sod all solar energy when you need it ie in winter!!!
This wolley tokenism re energy makes me sick. Go for the condensing boiler, only run it when you need to, use low energy bulbs and do your washing at 30C
> (In reply to James Moyle) Worth looking at an air source heat pump maybe? They use electricity to power the compressor, but are omething like 250% efficient (i.e you get 2.5 times the Kw out in heat production as you do per KW electricity put in) as opposed to 97 odd percent for gas boilers.
>
Unfortunately Electricity in the UK has 2.5 the CO2 emissions per kWh of gas. >
> Problems are that they run at a lower temperaure so you may need larger radiators. Also they arent as cheap as mains gas at the moent (defintely better than oil or lpg).
Why? please explain
>
> Work best when coupled with a solar pv installation on a feed in tarriff to offset the increased electricity costs.
> Work best when coupled with a solar pv installation on a feed in tarriff to offset the increased electricity costs.
??????????????
Solar PV in the UK is a joke; average solar radiaion in the UK is 912 kWH/m2 per year,solar PV is 10% efficient, ie 91 kWh/m2 (extremely expensive panels are 30% efficient; handy for NASA). You would need approx 100m2 of solar panels to give you an average of 1 kW, 2.5 kW output from your air source heat pump, cost only £60K for the panels. Of course you would het sod all solar energy when you need it ie in winter!!!
>
> Level of investment will depend on how long you plan on staying in the house versus payback period.
> Level of investment will depend on how long you plan on staying in the house versus payback period.
This wolley tokenism re energy makes me sick. Go for the condensing boiler, only run it when you need to, use low energy bulbs and do your washing at 30C
In reply to James Moyle:
One thing you need to consider when looking at a few of the "out there" heating systems, is the spec of your house.
As a lot of these air and ground source heat pumps, operate at lower temperatures, they need a highly insulated house. The high thermal mass of a house with poor insulation makes them pretty innefective. So for these to work you need a high spec air tight insulated house.
Now we are not talking about standard new build houses here, which in the whole scheme of things are pretty poor.
You need to be looking at something built under the old Eco Homes, or current Code for Sustainable Homes. These all offer percentage increases over standard building regs, with CSH going up to Level 6, including CHP, and then PassivHaus, requiring no additioanl heat input except appliances and occupation.
I live in a 1970s house, which I ripped appart, and rebuilt back to Swedish Regs, Basically CSH level 4, installed wet underfloor heating in the new part, either cavity wall or battened and 50mm insulation inside in the old part. Air tight (and this is important), and installed a pressurised gas boiler, and log burner. We are toasty, underfloor rarely goes on.
One thing you need to consider when looking at a few of the "out there" heating systems, is the spec of your house.
As a lot of these air and ground source heat pumps, operate at lower temperatures, they need a highly insulated house. The high thermal mass of a house with poor insulation makes them pretty innefective. So for these to work you need a high spec air tight insulated house.
Now we are not talking about standard new build houses here, which in the whole scheme of things are pretty poor.
You need to be looking at something built under the old Eco Homes, or current Code for Sustainable Homes. These all offer percentage increases over standard building regs, with CSH going up to Level 6, including CHP, and then PassivHaus, requiring no additioanl heat input except appliances and occupation.
I live in a 1970s house, which I ripped appart, and rebuilt back to Swedish Regs, Basically CSH level 4, installed wet underfloor heating in the new part, either cavity wall or battened and 50mm insulation inside in the old part. Air tight (and this is important), and installed a pressurised gas boiler, and log burner. We are toasty, underfloor rarely goes on.
In reply to kevin stephens:
That is the best that a lot of us can hope for living in the houses that we do, and a valid point. flashy fancy "Eco" gimmicks are just that.
>
> This wolley tokenism re energy makes me sick. Go for the condensing boiler, only run it when you need to, use low energy bulbs and do your washing at 30C
> This wolley tokenism re energy makes me sick. Go for the condensing boiler, only run it when you need to, use low energy bulbs and do your washing at 30C
That is the best that a lot of us can hope for living in the houses that we do, and a valid point. flashy fancy "Eco" gimmicks are just that.
In reply to James Moyle:
My folks have a woodchip burner system which seems very efficient and cosy (nice hi-tech wood-burning stoves.)
My folks have a woodchip burner system which seems very efficient and cosy (nice hi-tech wood-burning stoves.)
In reply to kevin stephens:
Wow, some fierce rhetoric there
I build new homes incorporating these technologies, so how about being sick at your assumptions rather than the facts. You may call it tokenism, however I find it encouraging that people are positively engaging in how they can reduce their environmental footprint in theor own homes.
It is sad that this country has a 50 year track record of poorly bult cheap housing and building regs that favour developers margins rather than the environment. However CSH is changin that. Ive tkaen a 15% hit on my margin since bulding (voluntarily) to ecohomes then CSH, mostly through the beurocracy involved in obtaining the certifiction, rather than the cost of technologies incorporated in houses. That is significant given the current climate for developers, and I am not eligable for grans or funding as commercial builds or householders would be.
> (In reply to peterjb)
Wow, some fierce rhetoric there
> [...]
> Unfortunately Electricity in the UK has 2.5 the CO2 emissions per kWh of gas.
>
At the moment it does, what happens when the gas runs out? Prices have been rising steadily. A large part the electrical loss of efficiency is through the loss of voltage in the transmission network, locally produced electricity is a lot more efficienlty used.> Unfortunately Electricity in the UK has 2.5 the CO2 emissions per kWh of gas.
>
> [
>
> Why? please explain
>
It generally produces water at 55 degrees which works best in a mordern home with underfloor heating, and requires additional heating to meet building regs requirements (6 I think, to prevent legionaaires).>
> Why? please explain
>
>
> ??????????????
>
> Solar PV in the UK is a joke; average solar radiaion in the UK is 912 kWH/m2 per year,solar PV is 10% efficient, ie 91 kWh/m2 (extremely expensive panels are 30% efficient; handy for NASA). You would need approx 100m2 of solar panels to give you an average of 1 kW, 2.5 kW output from your air source heat pump, cost only £60K for the panels. Of course you would het sod all solar energy when you need it ie in winter!!!
>
This would depend entirely on your location and orientation of the installation. I have installed several 3kw facilities that have far exceeded expectations and have cost 10 to 12k. Pyback has ben as low as 6 years. Poorly installed systems have a lot to answer for.> ??????????????
>
> Solar PV in the UK is a joke; average solar radiaion in the UK is 912 kWH/m2 per year,solar PV is 10% efficient, ie 91 kWh/m2 (extremely expensive panels are 30% efficient; handy for NASA). You would need approx 100m2 of solar panels to give you an average of 1 kW, 2.5 kW output from your air source heat pump, cost only £60K for the panels. Of course you would het sod all solar energy when you need it ie in winter!!!
>
>
> This wolley tokenism re energy makes me sick. Go for the condensing boiler, only run it when you need to, use low energy bulbs and do your washing at 30C
> This wolley tokenism re energy makes me sick. Go for the condensing boiler, only run it when you need to, use low energy bulbs and do your washing at 30C
I build new homes incorporating these technologies, so how about being sick at your assumptions rather than the facts. You may call it tokenism, however I find it encouraging that people are positively engaging in how they can reduce their environmental footprint in theor own homes.
It is sad that this country has a 50 year track record of poorly bult cheap housing and building regs that favour developers margins rather than the environment. However CSH is changin that. Ive tkaen a 15% hit on my margin since bulding (voluntarily) to ecohomes then CSH, mostly through the beurocracy involved in obtaining the certifiction, rather than the cost of technologies incorporated in houses. That is significant given the current climate for developers, and I am not eligable for grans or funding as commercial builds or householders would be.
In reply to kevin stephens:
Interesting post. but not sure about your "wolley tokenism" point. You obviously know a lot about it, but most people ate trying to do the right thing, with limited knowledge. Not long ago condensing boilers were a bit of a gimmick as were energy saving light bulbs. This year's tokenism is next year's significant development.
Interesting post. but not sure about your "wolley tokenism" point. You obviously know a lot about it, but most people ate trying to do the right thing, with limited knowledge. Not long ago condensing boilers were a bit of a gimmick as were energy saving light bulbs. This year's tokenism is next year's significant development.
In reply to peterjb:
The problem is, there is so much old housing stock, which I have pointed out, is not really suitable for these technologies. The cost of bringing even new spec built houses, up to a reasonable standard for the next 50 years of their lives, is costly and disruptive. The big housebuilders have lot to answer for, yet sell on energy efficiency and quality, yet are far from it.
Any Housing Association builds better houses than the big name house builders.
> I build new homes incorporating these technologies, so how about being sick at your assumptions rather than the facts. You may call it tokenism, however I find it encouraging that people are positively engaging in how they can reduce their environmental footprint in theor own homes.
>
> It is sad that this country has a 50 year track record of poorly bult cheap housing and building regs that favour developers margins rather than the environment. However CSH is changin that. Ive tkaen a 15% hit on my margin since bulding (voluntarily) to ecohomes then CSH, mostly through the beurocracy involved in obtaining the certifiction, rather than the cost of technologies incorporated in houses. That is significant given the current climate for developers, and I am not eligable for grans or funding as commercial builds or householders would be.
>
> It is sad that this country has a 50 year track record of poorly bult cheap housing and building regs that favour developers margins rather than the environment. However CSH is changin that. Ive tkaen a 15% hit on my margin since bulding (voluntarily) to ecohomes then CSH, mostly through the beurocracy involved in obtaining the certifiction, rather than the cost of technologies incorporated in houses. That is significant given the current climate for developers, and I am not eligable for grans or funding as commercial builds or householders would be.
The problem is, there is so much old housing stock, which I have pointed out, is not really suitable for these technologies. The cost of bringing even new spec built houses, up to a reasonable standard for the next 50 years of their lives, is costly and disruptive. The big housebuilders have lot to answer for, yet sell on energy efficiency and quality, yet are far from it.
Any Housing Association builds better houses than the big name house builders.
In reply to tobykeep:
The level of investment in these Token Gimmicks is astronomical. It is the house that is built around it that makes it work, it is not a simple bolt on addition.
I would love to see more people taking the initiative to improve efficiency. However if the technology gets bad press, for use in the wrong situation, that is far worse. Look at the bad rep timber frame housing had in england, and still does have with certain parts of the public, following shoddy construction in the 1970s by a big housebuilder cutting corners. It is easy to cut corners in traditional building, and get a poor but servicable house. Cut corners in some constructions and techniques, and you get crap.
> (In reply to kevin stephens)
> Interesting post. but not sure about your "wolley tokenism" point. You obviously know a lot about it, but most people ate trying to do the right thing, with limited knowledge. Not long ago condensing boilers were a bit of a gimmick as were energy saving light bulbs. This year's tokenism is next year's significant development.
> Interesting post. but not sure about your "wolley tokenism" point. You obviously know a lot about it, but most people ate trying to do the right thing, with limited knowledge. Not long ago condensing boilers were a bit of a gimmick as were energy saving light bulbs. This year's tokenism is next year's significant development.
The level of investment in these Token Gimmicks is astronomical. It is the house that is built around it that makes it work, it is not a simple bolt on addition.
I would love to see more people taking the initiative to improve efficiency. However if the technology gets bad press, for use in the wrong situation, that is far worse. Look at the bad rep timber frame housing had in england, and still does have with certain parts of the public, following shoddy construction in the 1970s by a big housebuilder cutting corners. It is easy to cut corners in traditional building, and get a poor but servicable house. Cut corners in some constructions and techniques, and you get crap.
In reply to peterjb:
Also don't discount solar hot water augmentation, but makes more sense than PV in high lattitudes (however installation costs appear to have been static over the past couple of years, which implies that although there should've been economies of scale as more people take up the technology, and its further 'productionised', either the companies involved are keeping margins very high or there is more demand than supply).
This is an option I'm looking into.
First port of call for anyone though is to insulate, insulate, insulate! I'm currently looking into doing under the floor, though I'm already running into issues with internal humidity just with double glazing and decent cavity wall and loft insulation and not heating any higher than 18 degrees C. 1930's houses don't seem to work well without lots of air changes per hour and some kind of blazing heat source
PP.
Also don't discount solar hot water augmentation, but makes more sense than PV in high lattitudes (however installation costs appear to have been static over the past couple of years, which implies that although there should've been economies of scale as more people take up the technology, and its further 'productionised', either the companies involved are keeping margins very high or there is more demand than supply).
This is an option I'm looking into.
First port of call for anyone though is to insulate, insulate, insulate! I'm currently looking into doing under the floor, though I'm already running into issues with internal humidity just with double glazing and decent cavity wall and loft insulation and not heating any higher than 18 degrees C. 1930's houses don't seem to work well without lots of air changes per hour and some kind of blazing heat source
PP.
In reply to PontiusPirate:
One of the problems with insualting old houses, is heat and air loss through parts of the structure.
The saying is "Build tight, ventilate right".
Insualtion is only half the battle, airtightness is just as important.
You can insulate as well as possible, yet have relatively easy paths for cold air and heat.
Windows, even standard UK spec double glazing need heet loss through them to keep them clear.
Take the example of an insulated wall and good windows, but with an un-noticed heat loss pass. Where does heat normally escape? through the coldest part, normally the windows. This heat loss keeps the window condensation free externally first, and internally second. If heat has an easier passage, the window condenses. Just think of your car. No heat loss through the glass, condensation and ice on the outside.
Controlled ventlation, and by association heat loss is good, uncontrolled heat loss and ventialtion is bad.
One of the problems with insualting old houses, is heat and air loss through parts of the structure.
The saying is "Build tight, ventilate right".
Insualtion is only half the battle, airtightness is just as important.
You can insulate as well as possible, yet have relatively easy paths for cold air and heat.
Windows, even standard UK spec double glazing need heet loss through them to keep them clear.
Take the example of an insulated wall and good windows, but with an un-noticed heat loss pass. Where does heat normally escape? through the coldest part, normally the windows. This heat loss keeps the window condensation free externally first, and internally second. If heat has an easier passage, the window condenses. Just think of your car. No heat loss through the glass, condensation and ice on the outside.
Controlled ventlation, and by association heat loss is good, uncontrolled heat loss and ventialtion is bad.
In reply to NorthernRock:
Agree totally. I build timberframe and it still takes some convincing for potential buyers. People are brainwashed into 'bricks and mortar'.
I am a small developer, and am struggling to stay ahead of the regulations which invariaby suit the big housebuilders with identikit houses.
Agree totally. I build timberframe and it still takes some convincing for potential buyers. People are brainwashed into 'bricks and mortar'.
I am a small developer, and am struggling to stay ahead of the regulations which invariaby suit the big housebuilders with identikit houses.
In reply to peterjb:
Gas won't run out, but it will get much more expensive. Electricity prices are more and more linked to gas. If in the very long term when nuclear generation replaces gas and coal then heat pumps will become a genuinely low carbon heating source (but not necesarily cheaper).
I Agree absolutely, my "Why" was re your statement that ASHP are "(defintely better than oil or lpg).
Often overlooked is the fact that gas condensing boilers can deliver even higher efficiencies partnered with low temp under floor heating, or multi service beams in commercial bildings
My solar radiation data is from CIBSE, efficiency data from manufacturers. How do you get your PV panels to run heat pumps in winter?
I spend my working life helping large manufacturing and commercial companies to reduce their energy use, cost and CO2 emissions so I tend to deal in fact rather than assumptions
Great stuff and I support you , I met with developers when I was working for the Scottish exec on a previous revision to building regs (approx 10 years ago): Pressure testing of homes was an example of something they couldn't handle on a quality and cost. I believe that concientous home owners should have correct info on which to make their choices. PV feeding ASHP just won't work.
IMO apart from solar hot water, renewbles for new householders is all about feeling good rather then making a real difference. In the UK it would be easier to build homes so well insulated they don't need heating anyway. The only way to make a real difference is to upgrade existing housing stock - even renew all the gas boilers
> (In reply to kevin stephens)
> [...]
>
> Wow, some fierce rhetoric there
>
> [...]
> At the moment it does, what happens when the gas runs out? Prices have been rising steadily. A large part the electrical loss of efficiency is through the loss of voltage in the transmission network, locally produced electricity is a lot more efficienlty used.
> [...]
>
> Wow, some fierce rhetoric there
>
> [...]
> At the moment it does, what happens when the gas runs out? Prices have been rising steadily. A large part the electrical loss of efficiency is through the loss of voltage in the transmission network, locally produced electricity is a lot more efficienlty used.
Gas won't run out, but it will get much more expensive. Electricity prices are more and more linked to gas. If in the very long term when nuclear generation replaces gas and coal then heat pumps will become a genuinely low carbon heating source (but not necesarily cheaper).
> [...]
> It generally produces water at 55 degrees which works best in a mordern home with underfloor heating, and requires additional heating to meet building regs requirements (6 I think, to prevent legionaaires).
> It generally produces water at 55 degrees which works best in a mordern home with underfloor heating, and requires additional heating to meet building regs requirements (6 I think, to prevent legionaaires).
I Agree absolutely, my "Why" was re your statement that ASHP are "(defintely better than oil or lpg).
Often overlooked is the fact that gas condensing boilers can deliver even higher efficiencies partnered with low temp under floor heating, or multi service beams in commercial bildings
> This would depend entirely on your location and orientation of the installation. I have installed several 3kw facilities that have far exceeded expectations and have cost 10 to 12k. Pyback has ben as low as 6 years. Poorly installed systems have a lot to answer for.
My solar radiation data is from CIBSE, efficiency data from manufacturers. How do you get your PV panels to run heat pumps in winter?
>
> I build new homes incorporating these technologies, so how about being sick at your assumptions rather than the facts. You may call it tokenism, however I find it encouraging that people are positively engaging in how they can reduce their environmental footprint in theor own homes.
> I build new homes incorporating these technologies, so how about being sick at your assumptions rather than the facts. You may call it tokenism, however I find it encouraging that people are positively engaging in how they can reduce their environmental footprint in theor own homes.
I spend my working life helping large manufacturing and commercial companies to reduce their energy use, cost and CO2 emissions so I tend to deal in fact rather than assumptions
>
> It is sad that this country has a 50 year track record of poorly bult cheap housing and building regs that favour developers margins rather than the environment. However CSH is changin that. Ive tkaen a 15% hit on my margin since bulding (voluntarily) to ecohomes then CSH, mostly through the beurocracy involved in obtaining the certifiction, rather than the cost of technologies incorporated in houses. That is significant given the current climate for developers, and I am not eligable for grans or funding as commercial builds or householders would be.
> It is sad that this country has a 50 year track record of poorly bult cheap housing and building regs that favour developers margins rather than the environment. However CSH is changin that. Ive tkaen a 15% hit on my margin since bulding (voluntarily) to ecohomes then CSH, mostly through the beurocracy involved in obtaining the certifiction, rather than the cost of technologies incorporated in houses. That is significant given the current climate for developers, and I am not eligable for grans or funding as commercial builds or householders would be.
Great stuff and I support you , I met with developers when I was working for the Scottish exec on a previous revision to building regs (approx 10 years ago): Pressure testing of homes was an example of something they couldn't handle on a quality and cost. I believe that concientous home owners should have correct info on which to make their choices. PV feeding ASHP just won't work.
IMO apart from solar hot water, renewbles for new householders is all about feeling good rather then making a real difference. In the UK it would be easier to build homes so well insulated they don't need heating anyway. The only way to make a real difference is to upgrade existing housing stock - even renew all the gas boilers
In reply to peterjb:
12K installation cost, 6 years payback period are you suggesting the panels save 2K a year? How much is the overall electricity bill?
> This would depend entirely on your location and orientation of the installation. I have installed several 3kw facilities that have far exceeded expectations and have cost 10 to 12k. Pyback has ben as low as 6 years. Poorly installed systems have a lot to answer for.
12K installation cost, 6 years payback period are you suggesting the panels save 2K a year? How much is the overall electricity bill?
In reply to peterjb:
Good look with it, people just need to be in a good timber frame house, to understand how warm they are.
I work on multistorey timber frame for the HAs. Yes we do get whacky cladding details on some, but others look just like traditional build.
> (In reply to NorthernRock)
>
> Agree totally. I build timberframe and it still takes some convincing for potential buyers. People are brainwashed into 'bricks and mortar'.
>
> I am a small developer, and am struggling to stay ahead of the regulations which invariaby suit the big housebuilders with identikit houses.
>
> Agree totally. I build timberframe and it still takes some convincing for potential buyers. People are brainwashed into 'bricks and mortar'.
>
> I am a small developer, and am struggling to stay ahead of the regulations which invariaby suit the big housebuilders with identikit houses.
Good look with it, people just need to be in a good timber frame house, to understand how warm they are.
I work on multistorey timber frame for the HAs. Yes we do get whacky cladding details on some, but others look just like traditional build.
In reply to kevin stephens:
Im not suggesting PV feed ASHP or GSHP however it is used to offset the cost. Therefore in summer you will gererate enough on a feedback tariff to offset the cost of import in winter.
What amazes me is the variety of conflicting and (often) expensive resources out there regarding renewables and their appropriate application. I am also alarmed by the get rich quick solar hot water companies who happily charge householders 8k for a 2k installation.
Surely we need to form a one stop shop for both housebuilders and commercial entities so they can get appropriate advice, realstic costings and guidance into the approriate grant funding available.
Ive found the problem with commercial is that as soon as someone hears 'coomercial' the price increases. For exaple solicotors on conveyancing identical property purchases (on the same site) one was for me personally for my btl portfolio, the other was through my company as a 'comercial' btl investment, 650 quid v 1250 quid.
Im not suggesting PV feed ASHP or GSHP however it is used to offset the cost. Therefore in summer you will gererate enough on a feedback tariff to offset the cost of import in winter.
What amazes me is the variety of conflicting and (often) expensive resources out there regarding renewables and their appropriate application. I am also alarmed by the get rich quick solar hot water companies who happily charge householders 8k for a 2k installation.
Surely we need to form a one stop shop for both housebuilders and commercial entities so they can get appropriate advice, realstic costings and guidance into the approriate grant funding available.
Ive found the problem with commercial is that as soon as someone hears 'coomercial' the price increases. For exaple solicotors on conveyancing identical property purchases (on the same site) one was for me personally for my btl portfolio, the other was through my company as a 'comercial' btl investment, 650 quid v 1250 quid.
In reply to kevin stephens: Another factor for me is the cost of utility infrastructure.
For exaple a small site of 11 houses I am doing at the moment cost 16k to get the gas connected. With hindsight Id have rather put in ashp at the same cost for the boiler and a solar pv installation to help offset the electrical cost, rather than fork out 16k to the most competetive gas co. (BG quoted 23k).
Ive just got planning for a small 2 bed house (calssic infill) to the rear of a commercial investment, and there the gas connection will cost 1800 quid, so instead im sticking in ashp and solar pv. The pv will generate approx 40% of the houses total requirement (including ashp) over the year and will cost about 3k to install.
For exaple a small site of 11 houses I am doing at the moment cost 16k to get the gas connected. With hindsight Id have rather put in ashp at the same cost for the boiler and a solar pv installation to help offset the electrical cost, rather than fork out 16k to the most competetive gas co. (BG quoted 23k).
Ive just got planning for a small 2 bed house (calssic infill) to the rear of a commercial investment, and there the gas connection will cost 1800 quid, so instead im sticking in ashp and solar pv. The pv will generate approx 40% of the houses total requirement (including ashp) over the year and will cost about 3k to install.
In reply to kevin stephens:
Even for solar hot water, the (average) 3K installation cost (or 2K with grants) would still be hard to justified economically. I did a SAP calculation on a new standard 3 bedroom semi-detached house. A 3sqm solar panel reduces water heating energy by about 900Kwh/year with a gas system. That's about £60? (=33 years pay back period) It makes good energy sense though as it needs zero input energy if it has a PV pump. I've read some people made their only solar panels out of painted brass pipes and glass boxes. Not sure how effective though.
From my understanding, wood boiler is the best option in terms of carbon saving, particularly if you have a local source of wood chip supply (while pellets still need to be manufactured and imported). However the high installation cost is hard to justified, particularly if you add in the extra cost of building a fuel store and maintenance. Good option for large housing development and industrial use with high loading though.
> IMO apart from solar hot water, renewbles for new householders is all about feeling good rather then making a real difference. In the UK it would be easier to build homes so well insulated they don't need heating anyway. The only way to make a real difference is to upgrade existing housing stock - even renew all the gas boilers
Even for solar hot water, the (average) 3K installation cost (or 2K with grants) would still be hard to justified economically. I did a SAP calculation on a new standard 3 bedroom semi-detached house. A 3sqm solar panel reduces water heating energy by about 900Kwh/year with a gas system. That's about £60? (=33 years pay back period) It makes good energy sense though as it needs zero input energy if it has a PV pump. I've read some people made their only solar panels out of painted brass pipes and glass boxes. Not sure how effective though.
From my understanding, wood boiler is the best option in terms of carbon saving, particularly if you have a local source of wood chip supply (while pellets still need to be manufactured and imported). However the high installation cost is hard to justified, particularly if you add in the extra cost of building a fuel store and maintenance. Good option for large housing development and industrial use with high loading though.
In reply to James Moyle: Whats wrong with a decent woodburner/multifuel like Morso or Clearview for your heating and maybe hot water with a back boiler attached - This can always be supplimented with a gas or elec system of your choice.
In reply to peterjb:
A very intersting point, my experience on industrial installations is tht BG woul have used the same sub contractor as the cheapest bid. Your homes are going to have such a low heat energy requirment that the diff in CO2 between ashp/gshp will be too small (in absolute terms) to worry about anyway.
Re the OP, a lot depends on the age and type of house, if the boiler needs changing it won't be that modern. so my advice get a modern condensing (with TRVs)and spend any spare money on insulation / draft proofing
> (In reply to kevin stephens) Another factor for me is the cost of utility infrastructure.
>
>
A very intersting point, my experience on industrial installations is tht BG woul have used the same sub contractor as the cheapest bid. Your homes are going to have such a low heat energy requirment that the diff in CO2 between ashp/gshp will be too small (in absolute terms) to worry about anyway.
Re the OP, a lot depends on the age and type of house, if the boiler needs changing it won't be that modern. so my advice get a modern condensing (with TRVs)and spend any spare money on insulation / draft proofing
In reply to James Moyle:
Long johns and a wooly jumper
Long johns and a wooly jumper
In reply to jamestheyip:
If you take brief shows rather than baths and do washing at 30 C there should be little need for hot water, I agree that solar water heating is not atracive financially or we'd all have them (as they do in Kalymnos!)
You really need to factor in the cost and CO2 load from transport, the replensihable weeod industry can cope with current users and a respectable growth rate. We would soon run out of land if everybody in the country wanted to use wood instead of gas, hence a litle feel good/tokenistic for the UK.
> (In reply to kevin stephens)
>
> [...]
>
> Even for solar hot water, the (average) 3K installation cost (or 2K with grants) would still be hard to justified economically.
>
> [...]
>
> Even for solar hot water, the (average) 3K installation cost (or 2K with grants) would still be hard to justified economically.
If you take brief shows rather than baths and do washing at 30 C there should be little need for hot water, I agree that solar water heating is not atracive financially or we'd all have them (as they do in Kalymnos!)
>
> From my understanding, wood boiler is the best option in terms of carbon saving, particularly if you have a local source of wood chip supply (while pellets still need to be manufactured and imported). However the high installation cost is hard to justified, particularly if you add in the extra cost of building a fuel store and maintenance. Good option for large housing development and industrial use with high loading though.
> From my understanding, wood boiler is the best option in terms of carbon saving, particularly if you have a local source of wood chip supply (while pellets still need to be manufactured and imported). However the high installation cost is hard to justified, particularly if you add in the extra cost of building a fuel store and maintenance. Good option for large housing development and industrial use with high loading though.
You really need to factor in the cost and CO2 load from transport, the replensihable weeod industry can cope with current users and a respectable growth rate. We would soon run out of land if everybody in the country wanted to use wood instead of gas, hence a litle feel good/tokenistic for the UK.
In reply to kevin stephens:
I attended a conference on wood fuel last year, organised by the Scottish Borders council. They were very supportive on the idea and suggested there's a good potential for commercial forestry in the area. There's probably not enough land down south to cope with potential local fuel demand but in Scotland I believe wood chip boiler is a very feasible option, specially for remote sites close to land which could be turned into woodland. Better than getting oil delivery or connecting to gas mains.
> You really need to factor in the cost and CO2 load from transport, the replensihable weeod industry can cope with current users and a respectable growth rate. We would soon run out of land if everybody in the country wanted to use wood instead of gas, hence a litle feel good/tokenistic for the UK.
I attended a conference on wood fuel last year, organised by the Scottish Borders council. They were very supportive on the idea and suggested there's a good potential for commercial forestry in the area. There's probably not enough land down south to cope with potential local fuel demand but in Scotland I believe wood chip boiler is a very feasible option, specially for remote sites close to land which could be turned into woodland. Better than getting oil delivery or connecting to gas mains.
In reply to jamestheyip:
During the conference I also watched a mobile chipper (size of a big truck) in operation. A few big tree logs were thrown into the chipper and 5 mins later you get a full trailer load of woodchip, ready to feed the boiler (although drying is preferred). What if every village maintains a community woodland and get one of those chippers to supply chips locally, will it not make sense financially? Perhaps CO2 emission from chipper and delivery could even be offset by the tree planting?
During the conference I also watched a mobile chipper (size of a big truck) in operation. A few big tree logs were thrown into the chipper and 5 mins later you get a full trailer load of woodchip, ready to feed the boiler (although drying is preferred). What if every village maintains a community woodland and get one of those chippers to supply chips locally, will it not make sense financially? Perhaps CO2 emission from chipper and delivery could even be offset by the tree planting?
In reply to jamestheyip:
The problem is the sheer quantities involved. Even using a wood burning stove for a largely decorative fire in the living room will use around a tonne per year. I was reading a leaflet recently, where a woodchip boiler was using something like 20 tonnes per year for a large house. That's literally HGV loads. Multiply that up and you're looking at massive amounts of fuel and vehicle movements.
> (In reply to jamestheyip)
>
> During the conference I also watched a mobile chipper (size of a big truck) in operation. A few big tree logs were thrown into the chipper and 5 mins later you get a full trailer load of woodchip, ready to feed the boiler (although drying is preferred). What if every village maintains a community woodland and get one of those chippers to supply chips locally, will it not make sense financially? Perhaps CO2 emission from chipper and delivery could even be offset by the tree planting?
>
> During the conference I also watched a mobile chipper (size of a big truck) in operation. A few big tree logs were thrown into the chipper and 5 mins later you get a full trailer load of woodchip, ready to feed the boiler (although drying is preferred). What if every village maintains a community woodland and get one of those chippers to supply chips locally, will it not make sense financially? Perhaps CO2 emission from chipper and delivery could even be offset by the tree planting?
The problem is the sheer quantities involved. Even using a wood burning stove for a largely decorative fire in the living room will use around a tonne per year. I was reading a leaflet recently, where a woodchip boiler was using something like 20 tonnes per year for a large house. That's literally HGV loads. Multiply that up and you're looking at massive amounts of fuel and vehicle movements.
In reply to peterjb:
Do you mind me asking roughly how many kWh per year you get or expect to get out of the PV system, and also how the feed in tariff compares to the purchase price for electricity at the moment?
> > Ive just got planning for a small 2 bed house (calssic infill) to the rear of a commercial investment, and there the gas connection will cost 1800 quid, so instead im sticking in ashp and solar pv. The pv will generate approx 40% of the houses total requirement (including ashp) over the year and will cost about 3k to install.
Do you mind me asking roughly how many kWh per year you get or expect to get out of the PV system, and also how the feed in tariff compares to the purchase price for electricity at the moment?
In reply to James Moyle: Thanks to everyone for their posts. to answer some of the questions, the house I live in is a victorian (1887) end terrace. It is in Bath. so there is no question of external insulation being allowed (I assume there is plannning permission required).
I have room for an air source heat pump and a double garage which could support a large area of PV panels. Installing underfloor heating is not something i'm too keen on at the moment, and as others have said, because the house is difficult to insulate I'm not sure how effective this would be.
I have consider biomass boiler but it does look economically viable plus I live in a smoke controlled zone!
So at the moment I am considering a Combined Heat and Power (Micro CHP) boiler that will generate some electricity and collect the waste heat for the heating system, combined with a solar water heater system. However I am still trying to get a price for a CHP boiler. Apparently BG are going to be the sole distributors of the Baxi one.
Also, how easy would it be to buy solar water panels and a hot water tank and install it into the main system?
Thanks again for all the useful advice
I have room for an air source heat pump and a double garage which could support a large area of PV panels. Installing underfloor heating is not something i'm too keen on at the moment, and as others have said, because the house is difficult to insulate I'm not sure how effective this would be.
I have consider biomass boiler but it does look economically viable plus I live in a smoke controlled zone!
So at the moment I am considering a Combined Heat and Power (Micro CHP) boiler that will generate some electricity and collect the waste heat for the heating system, combined with a solar water heater system. However I am still trying to get a price for a CHP boiler. Apparently BG are going to be the sole distributors of the Baxi one.
Also, how easy would it be to buy solar water panels and a hot water tank and install it into the main system?
Thanks again for all the useful advice
In reply to James Moyle:
sorry that should say doesn't look economically viable
> I have consider biomass boiler but it does look economically viable plus I live in a smoke controlled zone!
sorry that should say doesn't look economically viable
In reply to James Moyle: Depends what you mean by main system. Essentially you neat a heat store, .e. a hot water cylinder to accompanysolar hot water. Usually the cyliner is heated by an immersion, or a coil within it froma boiler (or both). Twin coiled cylinders allow you to have a coil which comes from you solar hw panel as well as a coil from you boiler. Therefore the boiler ony kicks in if the solar hw isnt getting it hot enough or you are using a lot of hot water (e.g. filling a bath or two).
If you are currentlyon a combi then it could involve a rejig of you hw system which could be expensive (in comparison to the return).
Insulation is definitely a good sarting point, you can never have enough in the loft, and even consider dry lining external walls, tough again this is desruptive and costly.
Something as simple as removing rads on external walls and putting in reflective material behind them can help a great deal.
One thing Ive done before is got a friend from the local fre service to bring around an Infra red camera to see where the house was loosing most heat from, then plug those gaps!
If you are currentlyon a combi then it could involve a rejig of you hw system which could be expensive (in comparison to the return).
Insulation is definitely a good sarting point, you can never have enough in the loft, and even consider dry lining external walls, tough again this is desruptive and costly.
Something as simple as removing rads on external walls and putting in reflective material behind them can help a great deal.
One thing Ive done before is got a friend from the local fre service to bring around an Infra red camera to see where the house was loosing most heat from, then plug those gaps!
In reply to peterjb: Thanks Peter.
would it be possible to run a combi, with a hot water tank for the solar, and then a thermostatic valve that uses the water from the solar tank if it is warm enough, or feeds it into the boiler if it too cold (but warmer than mains)?
I don't really want a boiler that heats up water simply for it to sit in a tank until it needs to be used, but like the idea of using solar to make a combi work smarter!
would it be possible to run a combi, with a hot water tank for the solar, and then a thermostatic valve that uses the water from the solar tank if it is warm enough, or feeds it into the boiler if it too cold (but warmer than mains)?
I don't really want a boiler that heats up water simply for it to sit in a tank until it needs to be used, but like the idea of using solar to make a combi work smarter!
In reply to peterjb:
Good point. Loft insulation is always the most cost effective investment. Put lots in. 270-300mm is the norm now. I've seen 400mm.
You can also insulate from the inside. Depending on whether you have wall cornice details you want to keep. You can get plasterboard with foam insulation bonded behind, or build a stud wall and insulated between the studs (behind the plasterboard). Kingspan/Celotex type of rigid insulation is about 50% more effective than fibre glass/mineral wool.
You can hire a company to do it for you but will be expensive. Generally most heat is lost through old doors and windows but they could be expensive to replace (hence long payback period).
> Insulation is definitely a good sarting point, you can never have enough in the loft, and even consider dry lining external walls, tough again this is desruptive and costly.
Good point. Loft insulation is always the most cost effective investment. Put lots in. 270-300mm is the norm now. I've seen 400mm.
> Something as simple as removing rads on external walls and putting in reflective material behind them can help a great deal.
You can also insulate from the inside. Depending on whether you have wall cornice details you want to keep. You can get plasterboard with foam insulation bonded behind, or build a stud wall and insulated between the studs (behind the plasterboard). Kingspan/Celotex type of rigid insulation is about 50% more effective than fibre glass/mineral wool.
> One thing Ive done before is got a friend from the local fre service to bring around an Infra red camera to see where the house was loosing most heat from, then plug those gaps!
You can hire a company to do it for you but will be expensive. Generally most heat is lost through old doors and windows but they could be expensive to replace (hence long payback period).
In reply to jamestheyip:
With the age of the house, you are gonna have to be clever and thorough, to achieve a high level of insulation, which will allow you to utilise the modern heating systems.
Insulating the inside is the best bet, it just depends on how much disruption you can live with, and how many original features you have already lost, that you may have been planning to add back anyway.
The closer the insulation is to the habitable room, the more effective the heating is, as you are not trying to heat up the thermal mass of the walls.
Use 50mm battens, and 45mm kingspan type insulation.
Dont forget heat loss in the floor voids, and air flow from where services and joists meet external walls.
Use a foil underneath any floor boards to form an air barrier, or better yet, overlay the floors with new flooring.
Or use a foil barrier underneath your carpet underlay, and seal it to the bottom of the skirtings, all to stop air leakage.
Get someone like Ventrolla to bring your sash windows up to at least 1920 spec (ha ha) They leak air like a sieve. Maybe add secondary double glazing, ugly I know, but not as ugly as plastic nasty windows.
With the age of the house, you are gonna have to be clever and thorough, to achieve a high level of insulation, which will allow you to utilise the modern heating systems.
Insulating the inside is the best bet, it just depends on how much disruption you can live with, and how many original features you have already lost, that you may have been planning to add back anyway.
The closer the insulation is to the habitable room, the more effective the heating is, as you are not trying to heat up the thermal mass of the walls.
Use 50mm battens, and 45mm kingspan type insulation.
Dont forget heat loss in the floor voids, and air flow from where services and joists meet external walls.
Use a foil underneath any floor boards to form an air barrier, or better yet, overlay the floors with new flooring.
Or use a foil barrier underneath your carpet underlay, and seal it to the bottom of the skirtings, all to stop air leakage.
Get someone like Ventrolla to bring your sash windows up to at least 1920 spec (ha ha) They leak air like a sieve. Maybe add secondary double glazing, ugly I know, but not as ugly as plastic nasty windows.
In reply to NorthernRock:
I like the idea of all this insulation, but what about ventilation? Surely by making your property virtually airtight you'll have all sorts of condensation issues?
I like the idea of all this insulation, but what about ventilation? Surely by making your property virtually airtight you'll have all sorts of condensation issues?
In reply to Ridge:
An effective air tight insulation will prevent rather than encourage condensation.
Condensation in a building element occurs when vapour is driven onto a cold impermeable layer, condense on the surface and have no way to get out. It usually happens at the 'cold' side of the insulation or at gaps to the cold elements (such as around metal frame windows).
The way modern construction works is to make the internal layers (before insulation) impermeable and air tight, and the outer layers more permeable, so that moisture will not be driven from the warm side to the cold side. It is achieved by a vapour control layer, being a foiled backed plasterboard, a polythene sheet or a sealed non-permeable insulation layer.
Another option is a breathing wall construction (like strawbale/lime/Panelvent) where moisture can be pushed out rather than trapped in. Old stone buildings (without insulation) work in similar way as everything is permeable. It works like a big woolen jumper.
To insulate a thick stone wall to modern standard it is however very difficult to make it breath properly, hence an non-breathable construction is more common. It is important to seal the insulation to prevent cold spots where moisture can condense.
Ventilation is controlled by fans at wet area (kitchen/toilet) and trickle vents at windows. Some air tight new build use a heat recovery system where you don't even need trickle vents. All the air flow is controlled by mechanical ventilation which retains warm hair and remove moisture.
> (In reply to NorthernRock)
>
> I like the idea of all this insulation, but what about ventilation? Surely by making your property virtually airtight you'll have all sorts of condensation issues?
>
> I like the idea of all this insulation, but what about ventilation? Surely by making your property virtually airtight you'll have all sorts of condensation issues?
An effective air tight insulation will prevent rather than encourage condensation.
Condensation in a building element occurs when vapour is driven onto a cold impermeable layer, condense on the surface and have no way to get out. It usually happens at the 'cold' side of the insulation or at gaps to the cold elements (such as around metal frame windows).
The way modern construction works is to make the internal layers (before insulation) impermeable and air tight, and the outer layers more permeable, so that moisture will not be driven from the warm side to the cold side. It is achieved by a vapour control layer, being a foiled backed plasterboard, a polythene sheet or a sealed non-permeable insulation layer.
Another option is a breathing wall construction (like strawbale/lime/Panelvent) where moisture can be pushed out rather than trapped in. Old stone buildings (without insulation) work in similar way as everything is permeable. It works like a big woolen jumper.
To insulate a thick stone wall to modern standard it is however very difficult to make it breath properly, hence an non-breathable construction is more common. It is important to seal the insulation to prevent cold spots where moisture can condense.
Ventilation is controlled by fans at wet area (kitchen/toilet) and trickle vents at windows. Some air tight new build use a heat recovery system where you don't even need trickle vents. All the air flow is controlled by mechanical ventilation which retains warm hair and remove moisture.
In reply to Ridge:
Jamestheyip explains perfectly.
I have said it earlier in the thread. "Build tight, ventilate right"
Build as airtight as possible, and design in air change systems.
Trickle vents over windows are not ideal. They have only been put in the heads of windows, because it is an easy solution. They will ventilate the area behind your curtains if you have them, and make cold air condense in this dead airspace.
Mechanical ventilation through the wet areas, is now the new norm, and as mentioned, heat recovery systems / whole house ventilation systems, are the best.
I have Swedish triple glazing throughout my house, along with a minimum of 225m wall insulation in timber frame, or 50mm internal kingspan in old house + 50mm blown cavity, 100mm kingspan in floors, and 400mm rockwool or 150mm kingspan in roof / ceilings. Airtight to 1.7l/m3/hr (current building regs say 10). No trickle vents, only mechanical ventilation in bathrooms. Night vent positions on windows (although not used much), Only tend to close curtains upstairs for light. With triple glazed windows, u value of 0.8w/m2/k (over 50% improvement over building regs) the windows are better insulating that most uk house walls, so closing the curtains to keep the heat in is not too much of an issue!
It is a complex field, and you cannot just bung loads of insualtion everywhere, and make your house airtight, without consideration for condensation, as you so rightly notice.
Plenty of insulation will improve considerably, but, unless you can achieve airtightness, after you improve to building regs standard + 25%, any further insualtion is diminishing returns, as the heat escapes through the easier routes.
Try the Green Building Forum, plenty of help on there!
Jamestheyip explains perfectly.
I have said it earlier in the thread. "Build tight, ventilate right"
Build as airtight as possible, and design in air change systems.
Trickle vents over windows are not ideal. They have only been put in the heads of windows, because it is an easy solution. They will ventilate the area behind your curtains if you have them, and make cold air condense in this dead airspace.
Mechanical ventilation through the wet areas, is now the new norm, and as mentioned, heat recovery systems / whole house ventilation systems, are the best.
I have Swedish triple glazing throughout my house, along with a minimum of 225m wall insulation in timber frame, or 50mm internal kingspan in old house + 50mm blown cavity, 100mm kingspan in floors, and 400mm rockwool or 150mm kingspan in roof / ceilings. Airtight to 1.7l/m3/hr (current building regs say 10). No trickle vents, only mechanical ventilation in bathrooms. Night vent positions on windows (although not used much), Only tend to close curtains upstairs for light. With triple glazed windows, u value of 0.8w/m2/k (over 50% improvement over building regs) the windows are better insulating that most uk house walls, so closing the curtains to keep the heat in is not too much of an issue!
It is a complex field, and you cannot just bung loads of insualtion everywhere, and make your house airtight, without consideration for condensation, as you so rightly notice.
Plenty of insulation will improve considerably, but, unless you can achieve airtightness, after you improve to building regs standard + 25%, any further insualtion is diminishing returns, as the heat escapes through the easier routes.
Try the Green Building Forum, plenty of help on there!
In reply to NorthernRock:
Thanks to you and james. Not just a case of nailing up some 2 x 2s, a bit of kingspan and some plasterboard then?
Thanks to you and james. Not just a case of nailing up some 2 x 2s, a bit of kingspan and some plasterboard then?
In reply to Ridge:
It could be. Tell me a bit about your house. You may be able to get away with it in some rooms.
It could be. Tell me a bit about your house. You may be able to get away with it in some rooms.
In reply to johnSD:
The government SAP figure is 850kWh/kW/annum for PV in the UK, but this is obviously an average over the whole country. In the SW we normally see 1000kWh/kW/annum.
The current purchase price is 10-15p depending on your supplier. The proposed FIT is 36.5p/unit for <4kW systems, with an extra 5p/unit for anything you export
> Do you mind me asking roughly how many kWh per year you get or expect to get out of the PV system, and also how the feed in tariff compares to the purchase price for electricity at the moment?
The government SAP figure is 850kWh/kW/annum for PV in the UK, but this is obviously an average over the whole country. In the SW we normally see 1000kWh/kW/annum.
The current purchase price is 10-15p depending on your supplier. The proposed FIT is 36.5p/unit for <4kW systems, with an extra 5p/unit for anything you export
In reply to peterjb:
this is a good starting point for that.. compare cost effective, C02 savings, etc. on a range of measures. Comes up with some interesting facts (one example is that external wall insulation on a poorly insulated property can be more cost effective at saving money/CO2 than double glazing)
http://www.tzero.org.uk/
(note: this has a SAP engine behind it)
> Surely we need to form a one stop shop for both housebuilders and commercial entities so they can get appropriate advice, realstic costings and guidance into the approriate grant funding available.
this is a good starting point for that.. compare cost effective, C02 savings, etc. on a range of measures. Comes up with some interesting facts (one example is that external wall insulation on a poorly insulated property can be more cost effective at saving money/CO2 than double glazing)
http://www.tzero.org.uk/
(note: this has a SAP engine behind it)
In reply to James Moyle: Depending on what type of property you live in, the most appropriate solution should be based on an analyis of your energy use. I live in a victorian house with single glazing, so my money is being spent on improved insulation levels, rather than a boiler which is a few percent more efficient. All things being equal, i would rank my preferences as follows;
proper controls on heating system
improved insulation & air tightness
condensing boiler
good insulation on hot water cylinder
solar hot water
i agree with comments that have been made about ground and air source heat pumps as not being the cure all. Unfortunately, they are marketed very effectively.
proper controls on heating system
improved insulation & air tightness
condensing boiler
good insulation on hot water cylinder
solar hot water
i agree with comments that have been made about ground and air source heat pumps as not being the cure all. Unfortunately, they are marketed very effectively.
In reply to NorthernRock:
I've read about airtight + air change systems, and I agree entirely and would go that way myself with a new build... However this is a slight hi-jack as you seem to know what you are talking about. Our house is in the French alps and is a traditional chalet of all timber construction, plus all the finishes are wood and we have under floor electric heating. The result is that it is an incredibly dry house. A friend of mine with a very similar house suffers from respiratory problems, he says due to his house being too dry. He installed a humidifier and says that it solved his problem BUT also he says that the heating seems more efficient as slightly humid air transmits heat better than completely dry air. I can see the logic... what is the truth behind this?
I've read about airtight + air change systems, and I agree entirely and would go that way myself with a new build... However this is a slight hi-jack as you seem to know what you are talking about. Our house is in the French alps and is a traditional chalet of all timber construction, plus all the finishes are wood and we have under floor electric heating. The result is that it is an incredibly dry house. A friend of mine with a very similar house suffers from respiratory problems, he says due to his house being too dry. He installed a humidifier and says that it solved his problem BUT also he says that the heating seems more efficient as slightly humid air transmits heat better than completely dry air. I can see the logic... what is the truth behind this?
In reply to James Moyle:
To go back to your original question (although it gets less foam on the lips)...
Faced with the same issue we:
- put in a high efficiency gas boiler
- put in a thermal store
- put in a back boiler to our woodburner (winter)
- put in hot water solar tubes (summer)
It might be "wooly tokenism" but...
- the boiler is pretty efficient
- we don't use gas other than for cooking on fine days in summer
- the woodburner takes a slice off winter use, but can't heat all of a big Edwardian house; however, the kitchen/breakfast room is toasty (and we're there for most meals unless visitors) and it puts a smile on your face.
We've gone long on loft insulation - it's practically full of the stuff - but can't do much about the solid wall construction of the house. We have 2 open fireplaces which are probably a luxury (draughts) but look lovely. we have secondary double glazing on 3/4 of the house (full on the extension).
My only regret is that we didn't have the floors up and put Celotex under when having plumbing done.
I guess it needs to be part of an overall lower impact though - we have reduced travel/petrol/air quite a bit and do 2 nights veggie a week, none of which has been a hardship.
We have an arrangement with a local tree surgeon re wood for stove and fires (the garage is full); shame the former system of "fuel allotments" no longer seems to exist.
We looked at combined heat/power - but these seem to make most sense in new build of sizeable developments (look at Scandinavia).
Just do your best.
JJL
To go back to your original question (although it gets less foam on the lips)...
Faced with the same issue we:
- put in a high efficiency gas boiler
- put in a thermal store
- put in a back boiler to our woodburner (winter)
- put in hot water solar tubes (summer)
It might be "wooly tokenism" but...
- the boiler is pretty efficient
- we don't use gas other than for cooking on fine days in summer
- the woodburner takes a slice off winter use, but can't heat all of a big Edwardian house; however, the kitchen/breakfast room is toasty (and we're there for most meals unless visitors) and it puts a smile on your face.
We've gone long on loft insulation - it's practically full of the stuff - but can't do much about the solid wall construction of the house. We have 2 open fireplaces which are probably a luxury (draughts) but look lovely. we have secondary double glazing on 3/4 of the house (full on the extension).
My only regret is that we didn't have the floors up and put Celotex under when having plumbing done.
I guess it needs to be part of an overall lower impact though - we have reduced travel/petrol/air quite a bit and do 2 nights veggie a week, none of which has been a hardship.
We have an arrangement with a local tree surgeon re wood for stove and fires (the garage is full); shame the former system of "fuel allotments" no longer seems to exist.
We looked at combined heat/power - but these seem to make most sense in new build of sizeable developments (look at Scandinavia).
Just do your best.
JJL
In reply to peterjb:
Is it the pinnacle of efficiency? Probably not. If it were I might cut/use +/-10% less wood each week.
Is is cheap and renewable? certainly.
Nice warm house? Yes.
> (In reply to kevin stephens)
> [...]
>
> Wow, some fierce rhetoric there
>
Having already had the Kevin Bloody Stephens 'woolly tokenism' treatment thrown at me before for having a Rayburn, I cut and split nearly all my own wood, some chestnut but mostly willow. It is entirely renewable aside from the chainsaw fuel/oil and it gives me heating, hot water and cooking. > [...]
>
> Wow, some fierce rhetoric there
>
Is it the pinnacle of efficiency? Probably not. If it were I might cut/use +/-10% less wood each week.
Is is cheap and renewable? certainly.
Nice warm house? Yes.
In reply to jon:
I can answer that for you - wet air requires more energy to raise the temperature by one degree than dry air, as the water in the air has a higher heat capacity. However, whilst your boiler will be working harder, humans are not very good thermometers and are more susceptible to changes in temperature when the air is humid than when it is dry.
> (In reply to NorthernRock)
>
> He installed a humidifier and says that it solved his problem BUT also he says that the heating seems more efficient as slightly humid air transmits heat better than completely dry air. I can see the logic... what is the truth behind this?
>
> He installed a humidifier and says that it solved his problem BUT also he says that the heating seems more efficient as slightly humid air transmits heat better than completely dry air. I can see the logic... what is the truth behind this?
I can answer that for you - wet air requires more energy to raise the temperature by one degree than dry air, as the water in the air has a higher heat capacity. However, whilst your boiler will be working harder, humans are not very good thermometers and are more susceptible to changes in temperature when the air is humid than when it is dry.
In reply to James Moyle:
I sort of understood the rise in temp difference between wet and dry air as it is also the explanation for the lapse rate varying in different conditions and giving rise to the Föhn effect etc. But hadn't realised that we are more aware of temperature differences in differing humidities... or perhaps I had. We always manage to put up with high temperatures better in dry air, I suppose......
Thanks for the reply.
I sort of understood the rise in temp difference between wet and dry air as it is also the explanation for the lapse rate varying in different conditions and giving rise to the Föhn effect etc. But hadn't realised that we are more aware of temperature differences in differing humidities... or perhaps I had. We always manage to put up with high temperatures better in dry air, I suppose......
Thanks for the reply.
In reply to James Moyle:
Interesting. Reminds me of sauna rooms. They always seems much hotter when you pour water over the stove.
> (In reply to jon)
> [...]
>
> ...humans are not very good thermometers and are more susceptible to changes in temperature when the air is humid than when it is dry.
> [...]
>
> ...humans are not very good thermometers and are more susceptible to changes in temperature when the air is humid than when it is dry.
Interesting. Reminds me of sauna rooms. They always seems much hotter when you pour water over the stove.
In reply to jamestheyip:
humans cool by evaporation of sweat, whether visible beads of persperation or invisible vapour from the skin; if the air is already saturated with water vapour then the sweat doen't evaporate so readily leading to over heating
humans cool by evaporation of sweat, whether visible beads of persperation or invisible vapour from the skin; if the air is already saturated with water vapour then the sweat doen't evaporate so readily leading to over heating
In reply to jon:
Your question has already been answered.
I just wonder why a chalet in the alps is so dry though?
When we go we always seem to have wet stuff everywhere, and lots of people breathing and sweating (how dare they) although that may be due to the fact we are on holiday, and in the mountains every day, and all the damp clothes that brings.
I do not see your comment as a hi-jack. As you cannot consider Eco heating systems and "gimmicks" without considering what goes on around them. I sort of hi-jacked the thread by leading it down that route, but it seemed prudent to do so, before money was spent and wasted by the OP.
Your question has already been answered.
I just wonder why a chalet in the alps is so dry though?
When we go we always seem to have wet stuff everywhere, and lots of people breathing and sweating (how dare they) although that may be due to the fact we are on holiday, and in the mountains every day, and all the damp clothes that brings.
I do not see your comment as a hi-jack. As you cannot consider Eco heating systems and "gimmicks" without considering what goes on around them. I sort of hi-jacked the thread by leading it down that route, but it seemed prudent to do so, before money was spent and wasted by the OP.
In reply to NorthernRock:
Our chalet, though built in 1983 is built completely traditionally - 11x20cm larch madriers (sorry, not trying to be smart, just have no idea of the word in English!) ie solid timber as opposed to a fake chalet construction - concrete blockwork with a timber cladding. We bought it in 1990 and have lived in it ever since. We extended it in 2006 and took the opportunity to completely re-do the existing roof. The roof is an incredible piece of work - it is 50cms thick - some of that being insulation obviously, but the most part ventilation to produce a completely cold outer roof so the snow doesn't melt. When you see houses out here with huge icicles hanging from them, it means they have little or no insulation or ventilation - snow melts and runs down the roof only to freeze on the 1 metre unheated eaves where it forms a dam over the period of the winter and the hundreds of litres of water that builds up inevitably finds it's way into the house... The wall insulation is also very efficient. Coupled with that is the fact that all internal finishes are timber, not hard (plaster on concrete/bockwork). My thoughts on it are that the timber finishes must absorb any small amount of humidity, to some extent... The fact that a typical wall is 11cms larch, 15cms Rockwool, 5cms space, 20mm pine finish, with all necessary wind barrier and vapour barrier, means that the temp gradient is very shallow and never has any condensation.
We have a ceramic tiled floor throughout with electric under floor heating (I know, not very traditional). In the winter we use that on minimum to maintain a temperature of 15°C and have an efficient wood burner (GODIN) to bump the temperature up to 23 - 25°C.
Despite the weather I'm looking out at at the moment(!), in general the Alps are a dry place to live - or at least, drier than the UK.
Basically, a house that is well constructed shouldn't be damp... I can only think the places in which you've stayed have been what I referred to above as 'fake' chalets?
Interestingly, my mate's house that is too dry, and who has installed the huidifier, has gone the route of completely sealing the house and has minimum insulation - 2cms(?).
Our chalet, though built in 1983 is built completely traditionally - 11x20cm larch madriers (sorry, not trying to be smart, just have no idea of the word in English!) ie solid timber as opposed to a fake chalet construction - concrete blockwork with a timber cladding. We bought it in 1990 and have lived in it ever since. We extended it in 2006 and took the opportunity to completely re-do the existing roof. The roof is an incredible piece of work - it is 50cms thick - some of that being insulation obviously, but the most part ventilation to produce a completely cold outer roof so the snow doesn't melt. When you see houses out here with huge icicles hanging from them, it means they have little or no insulation or ventilation - snow melts and runs down the roof only to freeze on the 1 metre unheated eaves where it forms a dam over the period of the winter and the hundreds of litres of water that builds up inevitably finds it's way into the house... The wall insulation is also very efficient. Coupled with that is the fact that all internal finishes are timber, not hard (plaster on concrete/bockwork). My thoughts on it are that the timber finishes must absorb any small amount of humidity, to some extent... The fact that a typical wall is 11cms larch, 15cms Rockwool, 5cms space, 20mm pine finish, with all necessary wind barrier and vapour barrier, means that the temp gradient is very shallow and never has any condensation.
We have a ceramic tiled floor throughout with electric under floor heating (I know, not very traditional). In the winter we use that on minimum to maintain a temperature of 15°C and have an efficient wood burner (GODIN) to bump the temperature up to 23 - 25°C.
Despite the weather I'm looking out at at the moment(!), in general the Alps are a dry place to live - or at least, drier than the UK.
Basically, a house that is well constructed shouldn't be damp... I can only think the places in which you've stayed have been what I referred to above as 'fake' chalets?
Interestingly, my mate's house that is too dry, and who has installed the huidifier, has gone the route of completely sealing the house and has minimum insulation - 2cms(?).
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