Split-system heat pumps are Ideal for warmer climates; a heat pump is an all-in-one cooling and heating system. During summer months, it works like an air conditioner; it extracts heat from inside your home and transfers it to the outdoor air. When the weather's cooler, it does the exact opposite, taking heat from outside and moving it inside. Believe it or not there is heat in cold air! Heat pumps can extract this warmth and send it into your home. They achieve this by doing the same thing air conditioners do only reversing the flow of the refrigerant. In hot weather air conditioners remove heat from the inside of your house through the evaporator coil and dispose of it outdoors through the condensing section. In cold weather the exact opposite happens using a reversing valve and the system removes heat from the outdoor air and pumps it into your home.
Heat pumps work very efficiently when the outdoor temperature is in the 50 F range. As the outdoor temperature drops, the heat loss of a home is greater and the heat pump needs to operate for longer periods of time to maintain a constant indoor temperature. Around 37 F many heat pumps reach what is called the balance point. At or near this temperature the heat pump needs to run constantly to produce enough heat to maintain a comfortable indoor temperature.
As the outdoor temperature continues to drop, the heat pump needs help from traditional electric resistance heat coils. These coils resemble the glowing wires inside your toaster and consume vast amounts of electricity as they burn to keep you warm.
Manufacturers can make heat pumps operate at different levels of efficiency. The more heat a system can produce or remove from a given amount of electricity, the more efficient it is. A common measurement of this performance is the Seasonal Energy Efficiency Ratio (SEER). SEER numbers can vary widely if you compare old heat pumps to new ones. Twenty year old heat pumps often had peak SEER numbers of 6. The minimum SEER you can buy today is 13. The highest SEER heat pumps made at present are a tad over SEER 17. Any heat pump that has a SEER rating above 14 is very high efficiency.
