The truth about heat pumps
There is a great deal of misunderstanding about heat pumps. I know this for a fact because I regularly receive calls about them. Those calls are either about comfort or high utility bills. Write this down. A properly-sized and properly-installed heat pump system, including ductwork, will provide total affordable comfort. I have performed energy analyses on 100s of house plans and have recommended that heat pumps be used for every single one of them. I have not recommended a gas furnace for a new house in more than 20 years. And, to the best of my knowledge, I do not have a single dissatisfied customer. My mother would say that the proof is in the pudding. And yes, before you even ask, many of them are in northern states. So why would some folks be unhappy with their heat pumps?
There are two types of heat pumps: 1) The air-to-air heat pump that has an outdoor unit and 2) the water-to-air geothermal heat pump that has no outdoor unit. While both types are excellent systems, the geothermal is my No. 1 choice for most houses. Be aware that a heat pump is special only in the heating mode. In the cooling mode it is just electric cooling like other air conditioning units. It is special in the heating mode because it provides heat at a high efficiency. An air-to-air heat pump uses one unit of electricity but gives 2.5 units of heat. That’s why we say that it is 250 percent efficient.
A geothermal system can provide heat at 400 percent efficiency. Most gas furnaces are rated at 80 percent efficiency. I always ask folks if they want 80 percent or 400 percent efficiency. My wife and I chose 400 percent more than 18 years ago and she will tell you that I am careful with our money. In either case, a heat pump can nearly always provide heat for less money than a gas furnace. Well, if this is true, why would anyone choose not to use a heat pump? It is very simple. It is called “Horror Stories of the Past.” In the last 30 years, I have heard them all. Let me see if I can teach this two-week course in two paragraphs.
1. If the ductwork design and installation are correct, the air-to-air heat pump can provide air that is about 20 degrees warmer than the room temperature. If cool 67-degree air goes into the heat pump, 87-degree air will come out. If a room is 87 degrees, it would be plenty warm; but 87-degree air blowing across your skin feels cool. Blow real hard on your hand. That is about 93-degree air, but even that feels cool. However, if you could blow enough 93-degree air into the room, the room would soon be too hot to enjoy. So 93-degree air is hot but it can feel cool if it is quickly moved across your skin. Now, let’s simply turn the thermostat up to 73 degrees. Now it is 73-degree air into the heat pump and 93-degree air into the room. Now say “aaahhh” very slowly on your hand. Wow, it is nice and warm.
The supply air temperature supplied by a geothermal heat pump will be about 30 degrees warmer than the air going into the unit. If the thermostat is set on 73 degrees, the air going into the room will be about 103 degrees. Well hot diggity dog. That’s even better … and cheaper too.
2. You are already thinking that it will cost you more if you turn the thermostat to a higher setting and you are right. But it probably isn’t nearly as much as you might think. It is estimated by some that it will cost about 2.5 percent more for each degree that you raise the thermostat setting. Let’s just say that it takes $75 average per month to heat a particular house. If you raise the thermostat from 68 degrees to 73 degrees, which is cool to warm, you might increase the heating cost by $9.38 per month. For the cost of a pizza, you can now be warm and comfortable for the whole month. REMEMBER, IF YOU TURN THE THERMOSTAT UP 3 DEGREES OR MORE AT ONCE, THE HEAT STRIPS MAY COME ON AND THE UTILITY BILL WILL BE HIGHER.
By next month you will have totally forgotten about winter but you will have the same concerns about comfort and utility bills. Therefore, I know that you will jump for joy to know that I have one more article to write on this subject and it will include cooling. See you in May.