As in my post below, start with a HRU on your A/C. By electric heat do you mean a heat pump or is it straight electric heat as a backup for gas? The size of your house is a problem you won't be able to overcome. We GC'd our retirement home here in cent fl, kept it to about 2000 sq ft. and also used radiant barrier roof sheathing. We have a 6/12 pitch roof to maximize convection cooling of attic. How many of you live in that house? Two washers and dryers? We have two portable gens for power failures. A 8000 watt that will run the house and a small 1000 watt stashed away with a small 'window shaker' to utilize for sleeping at night. The size of your house no doubt dictates a very large stationary genset. The whole house propane units are obscenely costly to run...you don't realize how cheap you can buy electricity until you have to make it yourself. How often does it run automatically in 'maintenance mode'? That can consume a heap of gas. We incorporated any ideas we could think of in the planning to minimize solar heating...garage on west side of house, minimal west windows and doors, low-e glass, 24 inch overhangs plus 6" gutters, and a 10' ceiling to let the warmer air stratify above our heads. When we started the planning of our new house about a year and a half ago, we had no idea of the wild runup in energy costs. If we had we probably would have opted to build even smaller. As it is, we ended up with a house that runs about $120 monthly electric bill. We are out in the country and this includes our water pumping expense. We keep the air at 78 and all lighting is CF. Large windows and sliding doors help minimize the need for turning on the lights. Would have loved to had a gas range but even when we built we were concerned about the cost of propane so went all electric.

Have you thought about a geothermal heat pump with a desuperheater? This would provide the cheapest heating and cooling. Your domestic hot water would be essentially free whenever youÂre using the A/C (the heat extracted from your home heats the hot water instead of being exhausted into hot atmosphere) and greatly reduced when heating.

Geothermal would certainly be expensive to install, but considering where energy prices are today and where theyÂre going to be tomorrow, this could be the Âcheapest option when you do a cost analysis over the next 10~20 years!

ItÂs also the greenest choice for active space conditioning.

SR

I'm concerned about future electric surcharges being applied to tankless electric water heaters. Power companies are concerned about the heavy instantaneous draw they put on the grid. I find the claims about energy savings somewhat overblown...maybe compared to a 20 year old tank heater...current tanks have VERY good foam insulation..put your hand on one and you'll see it's not even warm. Also I have a concern that although tank heaters are required to have the yellow energy label, I have yet to see a tankless with one. Are they slipping through some regulatory crack that's hiding their minimal savings over a tank unit??? The 85% efficiency they trumpet applies equally to a tank unit...it's a property of an electric element submerged in water...