UKC

Hi all, I've had a look through the archives on here but nothing specific came up. We're looking to fit a small heater into a Transit to take the edge off the cold air when we get back. Solar needs sun so I'm wondering if anyone on here has tried the setup, especially in our mountainous areas.
The van isn't a conversion as it is for business. Not really wanting to go down the gas or diesel route as the setup has to be very quick to remove after a trip. Many thanks.

In reply to olddirtydoggy:

Solar doesn't work - if there is enough sun to make any heat it is too hot to need heating. If there isn't enough sun to make it hot then there isn't enough sun to heat your van!

In reply to duchessofmalfi:

I noticed most of the website blogs with info are in the states. I was fairly sure it wouldn't work but you never know if somebody has found a system that works.

In reply to olddirtydoggy:

If you look at the power requirements of electric heating, and the power you can generate from rooftop solar, it's no surprise nobody had made it work.

I think the only way to do what you're looking for would be a portable open flame gas unit. They are very efficient at heating the inside of the van - sticking the kettle on heats my van faster then turning on the blown air heater - and safe enough as long as you have enough ventilation and a carbon monoxide detector, but produce a lot of water vapour which results in a lot of condensation. After cooking in cold weather, I'd normally leave the windows open for a while with the blown air heater running to dry the van out.

In reply to olddirtydoggy:

It is a tough one inside a metal box. A fan heater should be dry heat but I'm wondering if there is a way of powering it with some kind of battery. Somebody I've fallen out of touch with had a small van for solo trips where a second battery powered a light and a small fan heater. He claimed it worked but I'm wondering if anyone here has tried a similar system. I seem to remember that driving the van recharged the second battery.

In reply to olddirtydoggy:

Here's a quick fag-packet calculation for you.
A standard 100Ah leisure battery will theoretically put out 1.2kW for an hour. Draining the battery regularly will destroy it very quickly, so you could realistically get half an hour at 1.2kW. This should be enough to take the edge of the cold when you get back to the van. For comparison, a blown-air heater is about 2kW.
Recharging the battery will take a good 5 to 10 hours driving. So you'd have to do a good long drive in between every use of the heater.
If that works for you, then it wouldn't be hard to make a 12V fan heater.
You can forget solar. If you covered the entire roof of the van in good quality panels you might get enough charge over a full day for 15 minutes heat, but that would be a very expensive way to heat a van!

In reply to olddirtydoggy:

Nope don’t work

Use an eberspacher or similar

In reply to olddirtydoggy:

Why not just run an electric heater of the vans electrics, when you get back start the engine and hey-presto?

In reply to springfall2008:

A quick bit of googling for typical outputs from alternators suggests that an idling engine would only produce enough electrical power for a fairly puny electric heater. At best, you'd have to run the engine for quite a long time to get any significant temperature gains, at which point you might as well just have let the engine warm up and used the standard heaters (which is obviously also pretty wasteful).

In reply to Luke90:

If you are starting the van, might as well use the heating build in the van. Ok, not that powerfull for if the back...

You run hoses from the engine radiator to a heat exchanger in the back and to a heater element with fan. Although those are mostly combined units with a an electric and/or fuel powered heater system, like an Espar system.

In reply to Luke90:

With the van at a standstill there's also some risk of exhaust fumes being drawn inside the van. Probably not a particularly big risk but CO poisoning is an insidious thing, I don't think I'd want to make a habit of chancing it.

In reply to Luke90:


I'm pretty sure vehicles that run electrics from the van (e.g. ice cream van) have a fast idle setting. That said a good modern stop/start battery will most likely cover the peak for you assuming you are only using the heater for 5-10 minutes before the engine warms up?

In reply to Hooo:

You're missing an important part of the whole theory.
You need to be careful the 100Ah rating is a C1 rating not the normal C/20 rating - i.e. for a 20 hour discharge - you won't see all 100Ah in a one hour C1 discharge in a lead acid battery. You might get better results with other chemistries, but generally you have to oversize battery capacities for faster discharges.

In reply to Hooo:

Where do you get that figure from?

I wouldn't expect it to take that long unless your alternator was seriously underspecced for the job.

In reply to timjones:

I would tend to agree with Hooo, if you completely discharged a 100ah battery as well as damaging it, it would take a long time to fully recharge. Although a high powered alternator might theoretically recharge it very quickly because the output is regulated by battery voltage the high output tails of very quickly after a short time but well before a leisure battery is fully charged. This is with a standard typical split charge system, if you have a massively more expensive battery to battery charger such as a Sterling you might recharge in 1 to 2 hours. But for the costs of the above with decent batteries you would probably be better with an Eber or similar.