How much electricity does a heat pump use?

How much electricity a heat pump uses depends on its efficiency rating and your home.  Heat pumps have a Seasonal Energy Efficiency Ratio (SEER2) rating, which measures an air conditioner's cooling efficiency, and a Heating Seasonal Performance Factor (HSPF) rating, which measures how efficiently a heat pump warms up your home. 

A SEER2 rating calculated by dividing a heat pump or air conditioning unit's cooling output by its energy input. You can determine a HSPF rating by dividing the total seasonal heating output by total energy consumption.  The higher the SEER2 or HSPF rating, the more efficient the heat pump.

Electric heat pump vs gas furnace:  Which is better for the enviroment:

Heat Pumps are better for the environment for several reasons.  Since heat pumps only transfer existing heat, they need far less energy to operate than furnaces that work by generating heat.  Modern gas furnaces range from 90 to 100 percent efficient.  Today's heat pumps reach 300 to 400 percent efficiency or more.

This means that while a gas furnace puts out about the same amount of energy in the form of heat as it consumes, a heat pump puts out three to four times as much heat energy as it uses in electricity.

Are heat pumps suitable for cold climates?

It used to be that heat pumps struggled to keep homes warm in colder weather.  Many older heat pumps were paired with a backup heat source, such as an electric heating element or gas furnace, which would kick on when the heat pump could no longer keep up.

A newer cold-climate heat pump uses vapor injection to boost heating capacity when temperatures drop.  For Example, vapor injection heat pumps can provide heating at temperatures well below zero; some as low as -20 degrees Fahrenheit.  And many modern heat pumps also come equipped with variable-speed compressors that allow them to maintain consistent temperatures in cold weather.  This eliminates the wide temperature swings characteristic of older single-speed heat pumps.  As a result of these advancements, hybrid systems are a necessity only in climates that experience extreme cold.

What size heat pump do I need?

Heat pumps are sized in tons, a practice that stems from the early days of air conditioners when their cooling power was rated by the equivalent amount of ice it would take to supply the same cooler power as melting 2 tons of ice in a day.

Along with tons, heat pumps are also sized in British thermal units (BTUs), which is the amount of heat required to raise 1 pound of water 1 degree Fahrenheit.

While the sizing terms can be confusing, identifying the size of heat pump you need for your home isn't difficult.  Common sizing today ranges from 2 to 5 tons, or 12,000 to 60,000 BTUs.  Each ton is enough to heat and cool 500 square feet  This means a 2000-square foot home could require a 4-ton heat pumps, and a 2,500-square-foot home could need a 5-ton heat pump.  Since 1 ton is equivalent to 12,000 BTUs. making the calculation in BTUs is simple.  For example, a 2000-square-foot home would require a 4-ton heat pump, which equates to 48,000 BTUs (4x 12,000).