If you've been paying any attention to developments in HVAC, you've probably heard about heat pumps or "reversible" air conditioners. These units aren't new, but they've become somewhat more popular alongside mini-split systems. While many mini-splits utilize heat pumps to provide both heating and cooling, you can also buy traditional central versions of these devices.
The appeal of these systems should seem obvious: you can replace two separate HVAC systems with a single outdoor condenser unit and an indoor air handler. However, the reality isn't quite so cut and dry. If you're considering a heat pump for your next HVAC upgrade, you'll need to understand how these systems work and the benefits they can provide.
Energy Transfer Is King
Would it surprise you to learn that your air conditioner is likely far more efficient than your furnace? When it comes to thermodynamics, moving energy from one place to another is nearly always the more efficient option. Your air conditioner does this by absorbing heat (energy) from your home and releasing it outside. On the other hand, your furnace needs to convert fuel into energy, a less efficient process.
Since air conditioners move heat from one place to another, a similar design can bring that energy into your home. Even relatively cold air still contains heat energy, allowing a heat pump to scavenge warmth even on chilly days. As a result, you can pull heat from the outside air even when it's much colder outside than it is inside.
However, there are some limitations. The heat pump must work harder to extract sufficient energy as the temperature outside drops. As a result, you'll often use much more energy to run your heat pump when the thermometer starts to approach the freezing mark. Of course, the real-world efficiency will vary between heat pump manufacturers and models.
Designing Your HVAC System
Do the limitations of a heat pump system mean that you can't replace your furnace with one? It depends. If you live in an area where the winters typically don't get very cold, a heat pump may provide sufficient warmth all year round. Even better, you're likely to see a reduction in your utility bills by using this more efficient technology.
The answer can become trickier if you live in a less temperate climate. You may need a heat pump with an auxiliary heater in these cases. These backup heaters can provide a little extra boost, primarily for when your heat pump is either struggling to reach your thermostat setpoint or when the efficiency drops too drastically.
Another option is to supplement a forced-air furnace heating system with a heat pump. The pump will replace your AC in the summer while providing high-efficiency heating in the winter. If temperatures drop too low, your furnace can kick on to cover the slack. These systems can arguably provide the best of both worlds, reducing your utility bills while also reducing wear and tear on your furnace.
Contact an HVAC service near you for more information.
