Low electric use air conditioning

[booster]

All this talk about the e-trek trying to run the AC from the batteries.

How about someone come up with an absorption air conditioner? I had one in my first house (came with the house) that ran on natural gas. Worked fine until the heat exchanger sprung a leak.

Anybody have any idea how much propane one would use to get the 11,000 btu to match the smallest rooftop?

I just did a bit of reading, not very thorough, but interesting. If I am interpreting and converting correctly (please advise if I don't):

1 pound of propane has about 21,600 btu of energy

A "double efficient" absorption chiller has nearly 1 btu of cooling per btu of input (.9) so you would get about 19,500 btu of cooling per pound of propane, or 1.75 hours of AC per pound of propane. 30# of propane would run the AC for over 52 hours.

The unit could also be the heat for the van and the hot water, all in one.

They also list hybrid units that run on a regular compressor when electricity is present, so you would not use propane when plugged in.

These numbers seem awfully good, so I may have messed up somewhere.

I wonder if they could run one of these things on diesel fuel?

[Cubey]

Perhaps the efficiency is why they don't bother with them. They would freeze up badly too eventually. Think about how RV fridges are not frost free. They eventually ice up badly and you have to shut it down and defrost it. And it would take hours to get it putting out cold air again.

[booster]

Originally Posted by Cubey

Perhaps the efficiency is why they don't bother with them. They would freeze up badly too eventually. Think about how RV fridges are not frost free. They eventually ice up badly and you have to shut it down and defrost it. And it would take hours to get it putting out cold air again.

I am not an AC expert, but I think that the systems can be designed to work at different temps, so an AC would be at a higher temp and be similar to a compressor unit when it comes to freezeups. That absorption AC I had in my old house did not freeze up. Frigs are only frost free because the go back through the evaporator with heat, to melt the ice, periodically. It has nothing to do with the temps in the unit, as far as I know.

I guess the whole point would be to see if getting rid of the generator would be worth the switch to an absorption AC unit.

[markopolo]

I spent a bit of time reading about this today. It can and has been done as you mentioned for houses. I saw many comments about the concept being too large and too heavy for RV use.