Heat Pump Or AC Unit?
Choosing Heating Ventilation and Air Conditioning, or HVAC, equipment for your home should not be a matter of passing concern. Instead, you should focus on the long-term effects that your choice could have. If you buy an AC unit, you force yourself into the need to buy a separate heating element, usually a furnace. On the other hand, if you buy a heat pump, you gain one piece of equipment that should be able to handle both your heating and cooling needs.
How Does a Heat Pump Differ from an AC Unit?
Both AC units and heat pumps depend on the phenomenon of phase change. Briefly explained, this phenomenon is as follows: when a substance converts from a liquid to a gas, it is able to absorb heat from its surroundings. The net effect of absorbing heat is that the surrounding objects cool down. By forcing freon to vaporize in a set of evaporator coils, both heat pumps and AC units can absorb heat from their surroundings and then use a set of condenser coils to expel that heat in a different location.
The difference between an AC unit and a heat pump is that an AC unit is unidirectional and can only be used to cool your home, while with a heat pump, the function of the coils can be reversed. Thus, a heat pump can either absorb heat from your home to cool it down or absorb heat from the outside air to warm it up.
Limitations of a Heat Pump
Even when the air outside is cool enough to require a jacket, there is heat in the air. However, the closer the outside air gets to freezing, the harder your heat pump has to work. In fact, heat pumps are at their most efficient at heating a home when the air is between 40-60 degrees Fahrenheit. Thus, if you live in the North, a heat pump may not be the right choice for year-round operation. Instead, you should consider using the heat pump to cool your home during the summer and during the transition seasons to heat your home but using a furnace to heat your home through the dead of winter.
Other than the convenience of buying one piece of equipment, an air-source heat pump makes sense because, you can achieve efficiency levels of up 250%. In other words, for every unit of electricity that you pay for, your heat pump will generate 2.5 units of heat. The best furnaces top out at 98% efficient. Thus, a heat pump is a solid choice for moderate climates and can be used even in extreme climates to help combat moderately cold temperatures and to cool your home through the summer.