Air to Air heat exchangers.
These units can cost upwards to 4000 dollars installed. They can come with a ten year warranty. This is usually the cost for an 18000 BTU unit, but the smaller 12000 BTU units can come in allot cheaper. You can talk to your refrigeration expert about the process. An outside breaker, for safety is required in some provinces. They can be pad mounted, or mounted on your home foundation. The ten year warranty is great, as it is offered in some areas depending on where you live.
I always thought that these air to air heat exchangers were never that efficient. I thought they would only work good in the fall, or in the spring. I guess I was wrong. All that happens, is the refrigerant is pumped through as a liquid through coils at a lower pressure and temperature than the outside air. A fan pushes outside air over the coils. The outside air, gives up its heat to the liquid in the coils. The liquid evaporates, and is pushed into the homes air exchange unit. There, a fan blows over coils that release the heat into the room where it is set up.
The only downside, I have heard of some neighbors complaining about a little noise from the units when running. Maybe it is the defrost cycle in the winter, that causes the noise. But this is a rare complaint. Also, read your manual that comes with the unit. As it suggests not to run it a certain minus temperature. This is perhaps due to the coils frosting up, and perhaps the ice could build up enough to hit the blades.
I may get one this year. Or this fall. It is good for the summer also, as you can reverse the function of the unit and let it cool your room in the summer time. I have no problem in my house so far, with it being overly hot. But, the heat in the winter would surely come in handy to reduce the power bill. Also, these units are coming down in price, as time goes bye. As more people get into the business of installing them, so does the price come down.
I hope you all have a good evening, till next time...