Heat pumps are a top choice among homeowners in the Delaware Valley because of their energy efficiency. The equipment combines heating and cooling functions into a single system capable of controlling or reducing utility costs. As with furnaces and air conditioners, size matters for heat pumps. You need to know how to size a heat pump correctly so that you buy one that delivers efficient performance for your home.
Undersized and Oversized Heat Pump Problems
On the most basic level, heat pumps come in different sizes because houses come in different sizes. Different heat pump models can manage different amounts of air volume based on your home’s square footage. When you have a mismatch between heat pump capacity and building size, you can get:
- Inconsistent temperatures in your house
- Poor humidity control
- Excessive on/off cycling
- Short cycles
A heat pump that is too small for a house runs too much to remain energy efficient. The system continually tries to alter temperature for more air volume than it can physically handle. Consequently, you get higher utility bills, poor temperature control, and parts that wear out quickly. An oversized heat pump only runs in short bursts. This strains the motor and impedes management of the indoor temperature.
Learn How to Size a Heat Pump
The Air Conditioning Contractors of America have developed the Manual J method for selecting equipment sizes. The method evaluates these 8 factors:
- Square footage and shape of house
- Local climate
- Number and placement of doors and windows
- Air leaks
- Presence and quantity of insulation
- Presence of heat generating appliances
- Number of residents
- Temperature preferences of residents
Square footage and local climate represent primary factors. They determine air volume and how many days a year require temperature control. Air leaks and insulation affect performance but those issue can be corrected. Because doors and windows introduce air leaks, you need to consider their effect on heating and cooling. The direction that windows face can influence temperature. For example, sunny west-facing windows will heat a room considerably in the summer.
Heat Pump Sizes and Features
Manufacturers express the heating and cooling capacities of heat pumps in British thermal units. Approximately every 12,000 Btu on a heat pump represents the ability to condition 1 ton of air. To apply this to your home, know that every 500 to 600 square feet generally requires 1 ton of air processing. Therefore, a 2,000-square-foot home needs a 48,000 Btu heat pump. This is just a rule of thumb! Oliver highly recommends having a heat loss calculation completed to properly select the correct unit. This will also provide you with the information required to apply for Rebates if available.
Heat pump models also differ by SEER and HSPF ratings that measure operational efficiency. High ratings equal greater efficiency but are also accompanied by higher upfront costs. Blower motor type affects efficiency as well. Motors are fixed speed, multi-speed, or variable speed. Fixed-speed motors are the least efficient because they cannot adjust output according to demand.
Consult Home Comfort Specialists
The experts at Oliver know how to size a heat pump. We can calculate an ideal model for your home that takes in all pertinent variables. On top of heating and cooling, our company can also install insulation to increase overall comfort and efficiency. We’ve been upgrading homes in Pennsylvania, New Jersey, and Delaware for decades. Contact us about your heat pump questions today.
