Domestic DC aircon units

Re: Domestic DC aircon units

Jayboy wrote: »

Hi Guys

Hope all is great. Does anyone know whats the scoop with DC airons for homes?
I would love to run one off a battery bank. DO the guys make these? Is it possible?

Regards
Jay

There are a very limited number or A/Cs designed to run off DC, and they are very expensive and, IMHO, overpromoted in terms of their potential cost savings. Finding a highly efficient A/C such as a mini-split that also contains an inverter driven compressor motor (so that it can run at low speed instead of cycling on and off when its full output is not needed) should be your first choice. The losses caused by running an inverter from a battery bank to power it will not add much in the way of losses, especially if the main time you use it will be during the day when the PV is producing and you do not also have to figure in the charging efficiency of your batteries (more AH in to recharge than you get back out.)

If you get a full heat pump instead of just an A/C, the cost of running it for heat will be 1/3 the cost of direct resistance heating (which is never a good idea off-grid.)
If you do have grid available, then a heat pump will almost certainly be cheaper than propane, but somewhat more costly than natural gas if that is piped in.