Your air conditioner consists of four primary parts, and it's a very rare refrigeration system that deviates from this four part design, consisting of an evaporator, a compressor, a metering device, and a condenser. Heat is absorbed through your evaporator, and transferred to the refrigerant flowing within, the compressor compresses the refrigerant into a liquid, at the condenser, and there the heat is transferred through forced convection to outside ambient air , then the refrigerant is metered through the metering device back into the evaporator as a gas, where forced convection forces air laden with heat into the evaporator once again.
Note: Albert Einstein invented something called "the absorption chiller," a unique, but not so often used mode of refrigeration. I've actually had my hands on one, but only as a helper, and long ago. I'd have to further investigate the operation of this type of system to know if it fits the four part design listed above, or not.
So you see, an air conditioner doesn't add cold air to your home, it removes heat from it. It is important to realize that "cold" does not exist, but that heat is always present. There is, however, something called "absolute zero" which is the temperature at which there is said to be no hvac salary heat present. You'll never encounter such a temperature unless you've volunteered in some cryogenics program . . .following your life.
Okay, so following the logic established above, that there is always heat present in ambient air in livable habitats, then an evaporator, logically, can always absorb heat to transfer through refrigerant gasses into another area via a condenser, compressor, and metering device.
Finally, should you have absorbed the information above, I can answer the question: "What is a heat pump?" Answer: A heat pump is an air conditioner that employees a three way valve, also known as a "reversing valve" in order to change the direction of the refrigerant flow within a system, thereby making an indoor evaporator a condenser, and an outdoor condenser, an evaporator. Another simple answer would be, "a heat pump is an air conditioning system with not four, but five major components, the four usual ones, plus a reversing valve to change the direction of refrigerant flow in order to provide heat to the same conditioned space that it also can provide air conditioning to."
"So Todd, what you seem to be telling me here is that with a heat pump, even though it's ten degrees outside. . . .I can take the little heat that there is outside, and use it to heat my home?"
EXACTLY!
"So Todd, why would I do that? Why would I want a heat pump, when my gas furnace heats my home just fine?"
You can have a heat pump working in conjunction with your gas furnace-when it gets too cold outside for your heat pump to keep up with the demand for heat in your home, the gas furnace will take over. When it's warm enough that the gas furnace isn't needed-your heat pump can handle the load.
It is at this point that it has become prudent for me to explain that operating a heat pump would require a heat pump thermostat, as most thermostats can not operate a heat pump. However, I should also say that in this day and age of expensive, mostly digital thermostats, that you may already own a thermostat that CAN operate a heat pump. The other thing, besides the actual heat pump itself, and the thermostat able to run a heat pump is the thermostat wiring. A heat pump requires more actual thermostat wires in order for it to be hvac salary wired in and operate. Again, you may already have thermostat wire installed, with additional, unused wires, that will handle this application. . . .or maybe not. Thermostat wire is probably the least expensive concern here, and besides expense, and heat pumps are all about saving you money, heat pump heat is also the safest form of forced convection heating for residences or small commercial buildings.
I'm going to break from my typical stance here for just a second, and straight up advertise: Operating a heat pump in conjunction with a gas furnace, as I've mentioned up above. . . .isn't really the typical way of doing things here in Texas. I'll allow that it's a union, the gas furnace and heat pump, that is much more likely to be more common the further North one travels. More common in Texas is the union of a heat pump with an electric furnace, no worries at all. When it comes time to purchase a thermostat-should you be interested in a high quality digital thermostat, than I'll "pimp" the Honeywell Vision Pro 8000, a thermostat that can absolutely run any residential application imaginable, and one that I also happen to be familiar with, and have a great deal of confidence in. I've an image imported of the Vision Pro 8000 for you above. Simply owning a heat pump thermostat in no way guarantees that the thermostat will run a "duel fuel" application such as a gas furnace combined with a heat pump. Most often, a heat pump thermostat is designed to run an electric furnace combined with a heat pump, and one can not be used for the wrong application with any degree of safety involved.
Note: Should you be a "do it yourself" type individual. . . .then I want to discourage you in regards to a complicated thermostat such as the Honeywell Vision Pro 8000. I prefer the Vision Pro to other, comparable thermostats because of the reliability of the brand, and my familiarity with it; but programming one of these isn't going to be an easy thing for someone who is not a professional. Hey, my friend Ken did his by his self, but Ken is someone with exceptional ability. I've seen professionals spend hours trying to decipher the manual for thermostats able to run duel fuel applications and/or two speed compressor applications.
"Todd, my gas furnace has been doing an exceptional job of heating my home for many, many years. I see no reason at all to ever want or own anything BUT a gas furnace, so no thank you, Todd."
Your gas furnace is a thousand times more dangerous than a heat pump could ever be. The older your gas furnace is, then the more likely it is to have developed a hole in it's "heat exchanger," and should it have even the smallest crack in it's "heat exchanger," then you, and whoever enters your home or residence is being exposed to toxic and air conditioning units deadly carbon monoxide gasses. Once, when I worked at the Dallas Independent School District there was a librarian at Reinhardt Elementary School who was seeing a doctor for chronic headaches. I found a crack in the Libraries heat exchanger, and without needing or asking for anyone's permission or authority-I completely dismantled the system and left the library without heat. I did not need to have a dead librarian, or sick children on my conscious, understand? Sometimes where a medical doctor lacks an explanation, a competent hvac professional will have THE answer AND explanation.
"Todd, my electric furnace is WAY safer than a gas furnace; why would I want a heat pump, and that expensive, complicated thermostat you mentioned?"
Your electric furnace costs you many dollars a month more than a heat pump would, and there is no safer source of forced convection heat than heat pump heat.
"Todd, my flat has window units for cooling, and central oil or gas heat-I'm not sure, how does any of this apply to me?"
Window air conditioners can also be heat pumps, which can provide you with plenty of heat on mild Fall or Winter days. I even included some pictures of window air conditioner/heat pumps in this hub, check it out.
In conclusion, heat pumps are safer than gas furnaces, and cheaper to operate than electric furnaces-and there is no safer mode of forced convection heat than a heat pump. I hope I've done a decent job of explaining what a heat pump is, and provided a few reasons for why you might prefer to own one than whatever you own and operate now. As always, thank you very much for reading, and never fear any sort of question that you might have-ask it. Thanks again!
For information concerning the smartest type of conventional heat pumps for homes, follow the following link: