Solar Water heater

[extragoode]

I was looking at some of the home ecomodding threads about solar water heaters and notices that they can heat the water up 140 defrees F and it struck me that that's about the same temperature the engine block heater I was looking at would do, give 25 degrees. The biggest problem I have with an engine block heater is that only works when I'm home. While I'm at work, it's parked outside. The water would be warmed by the time I was parking, it'd just need to keep it from dropping back down to freezing. Same concept as a thermos, but active instead of passive. I could put on a lexan hood and save some weight too. The other thought was to plumb it to the bed and set it underneath a clear bed cap, but that'd be a lot piping that could leak. What do you guys see as problems?

[Ryland]

try looking for evacuated tube solar hot water collectors, then try to find some display samples, these tend to be tubes that are about 16" to 20" long, instead of the normal 6' to 8' long, just the right size to fit on your roof, or some other part of your car, and they get really hot, most solar hot water heaters get really hot, 160-180 degrees is common, I've seen them get up over 220-230 degrees if they don't have a good place to dump the heat, but most people who install solar hot water systems try to keep the temp lower to make sure pump seals, pipe insulation, and other rubber parts lasting longer, and to keep people from getting burns.

[AndrewJ]

I like the idea.

Sounds like the trick would be implementing it.

I think the way to do it would be to tap into the heater-core and mount a few collector tubes across your dashboard, assuming you have enough room.

That way you don't add a whole lot of extra tubing/coolant, and you're collectors are largely out of harms way.

[Peter7307]

Is a thermal blanket over the engine and under the hood a viable option ?
Cheaper , lighter , no plumbing needed.

Cheers , Pete

[extragoode]

Originally Posted by Peter7307

Is a thermal blanket over the engine and under the hood a viable option ?
Cheaper , lighter , no plumbing needed.

Cheers , Pete

What do you do when it warms up then?

[Peter7307]

The blanket goes on when you stop the engine at work.
Leave it on all day and take it off when you return after work for the trip home.
It won't add heat but it will stop heat escaping.

Another option is a solar cell to power a block heater. They are frequently used here to power battery chargers while the car is parked.

Cheers , Pete.