UKC

We bought a second hand tumble dryer last year when we moved into a caravan, and it worked ok. However, now it won't heat up. I'm sure someone could repair it, but we are still up to our necks in renovations so we won't be doing it. 

Currently, we are using a pulley in an unheated, uninsulated but well ventilated utility room. I put a small electric heater under it with windows open and it drys fairly well. 

So what I want to figure out, is this system more energy efficient than a tumble dryer? Trying to decide whether to buy another tumble dryer or not. 

This is the heater we are using https://www.screwfix.com/p/ch-2000m-turbo-freestanding-convector-heater-wit...

If the heater is 2kw you need to know what KW the dryer is. 

Work out how long you run the dryer for and how long you run the heater for and you can work out how much each one costs. 

Does 1 line load = what you would put in the dryer for one load because you will need to take that in to account too. 

Might not be as simple as that as both the heater and dryer probably won't be running on full power continuously.
One option to work it out would be using the data obtained from a smart meter or perhaps even better from a meter connected to each device.
Regarding dryers, they should come with paperwork that says how much power/energy they use for a typical load.

If you had been able to get a dehumidifyer that might have been a better option than the heater, but in real terms you'll be splitting hairs compared to heating costs of the house.

People with passive houses often have a dedicated drying cupboard so the damp air get sucjed out but the cold air re-warmed. Apparently you can get single room x-flow heat exchangers, might be worth looking into? (or prompting discussion here if anyone knows more about the efficiency/effectiveness of them?) 

Apologies for stating obvious but we hadn't realized with our tumble drier that impossible for dryer to heat for short times since last part of a cycle runs without heat. Also heat cutout may activate if fluff filter not emptied and some dryers need resetting with button.

Possibly spin clothes harder/longer. We have a simple unheated, well ventilated leanto and eventually clothes do dry with winter sun etc. Items needed quickly are dried in a reasonably ventilated room or over rad. Might even be cheaper to have more changes of clothes for everyday use so fast drying isn't essential.

We do have a heated drying rack, there is a recent UKC thread on these. But rarely use. Low wattage but I'm not sure of economics as it's on quite a long time.

Have you ever had or used a free-standing spin drier? If you can pick one up second hand it might be a good buy. Spin driers are much faster than the spin cycle of a standard washing machine, and because no heat is involved they are probably money savers if you are drying clothes indoors. If you've no experience of one, you will be amazed at how dry things come out. We dry clothes indoors in bad weather in a cupboard with a dehumidifier and an electric fan heater running from a time switch which comes on at intervals to raise the cupboard temperature as dehumidifiers are a lot more efficient if the temperature is 15*C or more. If the room you're drying the clothes in gets really  humid clothes will never dry, but you probably knew that. 

We do have a dehumidifier, but mostly we are running it in short bursts in our entrance to keep the damp at bay there until the specialists can come and deal with that. I could use that in our utility, but I presumed the open windows would be enough for that. We don't get condensation from the laundry when windows are open. 

Yes, running time probably needs thought about. Maybe I need to buy a timer for the heater to be efficient as we often put it on and forget to go and check when things are dry. A tumble dryer will at least stop. 

I will check about reset and double check filters etc, thanks 

Our utility room is only one step above a lean to. At present, it is our only pulley and has 6 laths, so stuff is packed quite close together. In summer, it dries fine like that, but with this colder weather, it's needing some assistance. We do have a balcony which normally has a pulley too, which does help as you can spread stuff out more, but currently we are getting work done there so pulley has been taken down. I'm not sure if that will dry things eventually without any heat. Will have to see when we get it back up. One problem with things taking ages to dry is that they smell fousty as they have been damp for too long. 

Thankfully, today was windy and dry for just long enough to get my washing out on the proper line for a wee while before the rain started. So it smells nice from being dried outside, and only needs a little finishing in the utility room 

We had problems getting things dried in the house last year. We got a dehumidifier a few weeks ago and it’s worked really well so far. We plonk it between two drying racks of clothing and everything on them is dry in about four hours. 
 

The baseline relative humidity in the house has dropped too, from 60-70% to ~50%. 

Likewise, we never use a tumble dryer. Last month we got a dehumidifier and tend to leave it on overnight with the ‘fan’ setting(more efficient mode). In this mode the clothes on a standard rack dry overnight in a non-heated room.

There was a massive and useful thread on this last year. 

https://www.ukclimbing.com/forums/off_belay/how_do_you_dry_your_clothes-752...

Check your washer manual for your favourite cycles spin rate. We found that our quick wash only span to 800rpm and giving it an extra spin to 1200rpm removed 700g more water. 

This is a good overall guide

https://www.which.co.uk/news/article/whats-the-best-and-cheapest-way-to-dry...

I think your method will be inefficient to be honest, and more so as it get's colder. You need the ventilation and the heat but your method will mean the 2kW heater is 'on'* more the colder it gets, possibly 'on' continuously while still taking a long time when the temps really drop over winter (maybe too long leading to the dreaded musty smell).

*As I'm sure you know it has a thermostat.

I like a dehumidifier in a well insulated air closed room, for the pros listed in the article and I don't like wasting heat through open windows.

Good quality heat pump tumble driers are a great investment if you do a lot of laundry, eco sound, but not cheap.

Second the advice above about filters - we learnt about that the hard way after a bill for an engineer! 
 

the other thing to check is the outflow pipe.  This stopped our dryer working (it’s a combined washer/dryer) for some reason despite it being less of an issue for the drying function than the washing one (which was working fine!) 

I think that having the heater on AND the window open isn't optimal. Have the heater on with the widow closed so that the heat builds up (and the humidity rises) then shut off the heater and open the window to allow the warm, humid, air to escape. Repeat until dry.

As an aside, what are the specialists intending to do / claim they can do? And have they mentioned the words "rising damp", or "damp proof course". If so, kindly cancel them as they are shysters.

Have a read:  https://www.heritage-house.org/damp-and-condensation/the-fraud-of-rising-da...

Your damp issue will be likely be condensation.

They have a number of things they are proposing. We have "penetrating damp" due to the house being built onto a slope. So we are going to deal with adding extra drainage at the the back, and they are proposing adding a plastic membrane and a fungicide treatment. There is condensation too, but we had already identified that it was a different issue to the other dampness. The condensation changes with weather conditions etc, but the other dampness doesn't. We have one bit which they describe as rising damp, but most of it is due to where the house is built. 

Ahaaa! The slope of doom. Sounds like they're maybe OK then... Although they do use the red flag term of rising damp! We have a similar issue that we need to deal with at some point, but the slope is solid rock so digging and adding draining will be a challenge...

I'm no expert, but it seems like the most effective method for this tissue is digging away as much material from the side of the house as possible. Even better, creating a swale with drainage but you'd need a mini digger for that probably. 

If its cavity walls and has insulation, that can actually bridge dampness across the gap. In that case, removing the old insulation and adding some external insulation and a waterproof membrane might improve things. That happened at my mum's in the cold north wall of the kitchen. The external render on the bricks had cracked, so water could get in. Instead of then just draining down the cavity it bridged across at various spots. 

I'm not a frequent poster but with a similar use-case I found the following worked: I bought a £50 spin dryer of eBay (2,800rpm). The drum is not huge so one load of washing, from the washing machine, needs to be split into 2 spin dryer cycles. I run the spin dryer for about 5 minutes... this gets most washing, including bedding, feeling "just a bit damp". I then just put the damp washing on a clothes airer overnight... its then dry the following morning.

The spin dryer, although a bit 1980s in tech-trend-terms, gets "loads" of excess water out of the washing... its cheap to run (doesn't have a heating element) and quick (5 to 10 minutes max).

Just a though based on what works for me. AP

I'd imagine that heating it with the windows shut and a dehumidifier running is about the optimal approach? Maybe a fan too to keep the air circulating. Particularly if there are any easy ways to improve the heat retention of the room, eg blocking up obvious cracks under doors etc. The dehumidifier will be more efficient at higher temperatures, but you'll also be getting moisture out of the clothes more quickly with warmer air around them. Seems intuitively likely to be more efficient than heating the room repeatedly, although maybe someone on here will have back-of-the-envelope sums to the contrary?

Update - I did some back-of-the-envelope sums. Someone can correct me if I'm wrong, but...

Assuming that a smallish electric heater uses about 2000W, a small dehumidifier uses about 150W and a normal fan uses about 80W, it's worth sticking a dehumidifier and/or a fan in the mix for even a fairly marginal reduction in the length of time that you need to use the heater for.

Conversely, if you were just using a dehumidifier then it seems like adding a heater would have to give you a pretty serious reduction in the time taken to get stuff dry before it was effective on a purely energy-saving basis, which I'm guessing would mainly be the case if you were able to contain the extra heat fairly efficiently in the area around the drying clothes (ie if they're in a reasonably small and well-insulated room), although you might decide to run the heater even if it's a bit less efficient overall if it meant that you had dry clothes today rather than next week. You might also consider heating worthwhile if you wanted the space to be warm anyway.

Passive houses don't (in my experience) have dedicated drying cupboards. Most passivhaus houses/flats I work with have tumble driers, although some look to save on PE and just air dry in a room with extract if they have the space.

Fair enough. My example was form a guy (climber actually) who's a passivhaus designer and is doing a deep retrofit. He's got a cup ajrd and said it was a good option. I thought he said it was popular  / common but it was a while back we were talking about it so I might have misremembered. 

Well the single room heat recovery units definitely exist and are a good suggestion to throw into the mix. Much lower running coasts than a dehumidifier. There's plenty on sale so people must be using them!