A variety of installation factors contribute to an air-source heat pump’s overall efficiency. Did you know that failure in any one of them can cause unnecessary stress on the heat pump? If you’re thinking about heat pump installation in your home, there are four things you need to address beforehand.
Sizing. In sizing a heat pump, many factors need to be considered, in addition to your home’s size and layout. These include the home’s insulation and airtightness, the number and type of windows, the climate, and landscaping around the home, among other things. Taking into account these factors, a trained professional should perform a Manual J heating and cooling load calculation to determine the right size heat pump for your particular home. A Manual D calculation will then determine the design and size of ductwork for your heat pump installation.
Refrigerant charge. Having an incorrect refrigerant charge can result in poor efficiency and performance, and eventual breakdowns. A professional installer should make sure the refrigerant charge for your heat pump installation is according to precise manufacturer’s specifications.
- A charge that is off by as little as 20 percent can affect performance significantly.
- Once the pump is installed, a refrigerant check should be as required part of annual maintenance. Unless your system develops leaks, the level of refrigerant should not go down from year to year.
Airflow. A heat pump’s airflow should measure above 400 cubic feet per minute (cfm) per ton, with an ideal range of 400 to 500. Airflow that drops below 350 could compromise performance severely. Properly sized and sealed ductwork ensures good airflow, as does proper matching of the air handler to other components. Blocked vents, closed doors, and the heat pump’s fan speed all come into play as well when it comes to restricted airflow.
Ducts. Leaking ducts can reduce airflow while wasting energy and risking poor indoor air quality. Ducts should be sealed with duct mastic and/or metal tape. In addition, before routing ducts through attics, crawlspaces, etc., make sure you surround them with sufficient insulation to prevent heat transfer. In addition to efficiency, proper ductwork contributes to a healthy living environment.
Stack Heating & Cooling has been providing expert HVAC service to the Greater Cleveland area since 1976. For more information about heat pump installation or other topics, please contact us today.
Our goal is to help educate our customers in Cleveland, Ohio 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