The process of sizing a heat pump for a new installation requires more than a glance at the existing HVAC system and finding the square footage of your home. While the size of your home does impact the size of the system you choose, the calculation also involves the energy efficiency of your home and factors about your home that impact your cooling and heating load.
The HVAC industry uses tools to calculate the conditioning load in your home. The software applications are called Manuals J and D and require these variables about your home to arrive at the right size for the heat pump:
- Cubic footage of your home;
- Insulation levels in the floors, attic and walls;
- Windows, their efficiency and orientation to the sun;
- Air infiltration rates;
- Heat-producing appliances;
- Lighting types;
- Household occupants size and ages;
- Preferred temperatures;
- Layout of your home; and
- Landscaping factors.
Once the contractor knows the size for your system, he or she can assess the ductwork configuration and integrity and use Manual D to make changes, if required. Making sure that the ducts have minimal leakage and adequate insulation is as important when sizing a heat pump as getting the right size for the appliance itself. If the ducts are too small, they’ll be noisy and when they’re too large, the airflow will be compromised and some rooms won’t be comfortable. Ductwork with leaks increases energy bills.
When heat pumps are too large, they run for short periods more frequently. During the summer, the heat pump won’t remove as much humidity or airborne particulates. Short-cycling drives up electric bills and increases the wear and tear on the equipment, hastening breakdowns. In the winter, the solid objects won’t have time to warm sufficiently, or parts of your home will be chilly. If the heat pump is too small, it won’t be able to deliver as much comfort during weather extremes.
If you’d like to learn more about sizing a heat pump, contact Team Bob’s Heating Cooling Plumbing. We’ve provided HVAC services for Grand Traverse County and the surrounding areas for more than 30 years.
Our goal is to help educate our customers in Traverse City, Michigan and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about heat pumps and other HVAC topics, download our free Home Comfort Resource guide.
Image courtesy of Shutterstock