What is a Reversible Heat Pump, and Should You Use One?
Often propped up as a fashionably simple, one-size-fits-all solution to home heating and cooling. The reversible heat pump seems almost too good to be true. Fortunately, it’s a real climate control solution that can heat and cool your home electrically without needing a gas line or refueling.
So, What Exactly is a Heat Pump?
A heat pump isn’t the most intuitive thing to visualize, and, unless you have a background in thermodynamics, you might be scratching your head. The short answer is that heat pumps actually move heat from one location to another! If that sounds familiar it’s probably because heat pumps are actually identical in function to standard air conditioners! Air conditioners regulate the temperature of a given space by moving a refrigerant through it that’s colder than the surrounding air. As the refrigerant passes, it absorbs heat to be deposited elsewhere. The temperature of the fluid can be changed and permitted to absorb more or less heat by adjusting the pressure of the fluid using a compressor. This is how an air conditioner can pull heat from inside your home and move it outside during hot summer months.
In the winter, a reversible heat pump simply switches this process around. By swapping the roles of condenser and exchanger on either end of your system, a heat pump can pull heat from the cold outside air and deposit it inside your home. To do this effectively, the refrigerant liquid needs to be capable of reaching temperatures that are colder than the outside air. Amazingly, as cold as it may feel outside, there’s still heat energy there which can be used to warm up the refrigerant before it’s passed back inside the home.
Still confused? This video explains the process in greater detail!
Should You Use A Heat Pump?
A major factor in the effectiveness of a heat pump is climate. Though it’s technically possible for refrigerants to get colder than even the harshest Illinois’ winters, as the outside temperature drops so do the effectiveness of your heat pump. This is why you see more heat pumps farther South, while northern climates typically use gas and oil furnaces. To make up for the harsher, cold climates of the North, heat pumps have an emergency heating element installed. When the outside temperature gets too cold for the standard compression cycle, an electric heating element activates, boosting your heat pump’s ability to generate heat. The heating element then works like an electric furnace and can keep your home warm.
Calculating the difference between the costs of a heat pump and a fuel-fired furnace is a little tricky. Efficiency and BTU output per dollar are calculated differently for each, which makes getting a set comparison difficult. Differences in home construction, the price of gas, and how warm you keep your home can further complicate matters. Fortunately, you will typically find that the difference in cost is minimal. You’ll need to do a cost per BTU analysis to make sure you’re getting the most value out of your system.
Home Design Factors
The last factor to consider when buying a heat pump is how your home is designed. Drafty, cold homes aren’t a good candidate for heat pumps since you will likely want a stronger heat source during the winter. Though a heat pump can keep a drafty home warmer, the colder it gets outside the less effective a heat pump becomes, and while this is true of any heating device (the colder a room is, the harder a heater will have to work to warm the room up), heat pumps have a slightly narrower operational margins than standard furnaces and might not be the best heating solution for your home.
No matter what you decide, heat pumps are becoming more effective every year. Hfigher efficiencies, greater cold tolerances, and increasingly accurate control systems, an electric heat pump is often a great way to control the climate in your home year-round without worries of fuel consumption.