A Checklist for Ducted Heating and Cooling Equipment

Maggie Leslie

 

Your home can be heated or cooled using electricity, gas, geothermal energy, solar energy or a combination of each. Radiant floor heating systems are an inherently efficient way to heat because there is no heat lost through duct work. Ductless minisplits are also very efficient systems that are becoming more common. However, ducted forced air heating systems can a be very efficient option if designed and installed properly. The checklist below should be considered when installing any type of ducted system.

■ A room-by-room Manual J heat loss/heat gain calculation must be completed. Maximum over sizing limit for air conditioners and heat pumps is 15 percent. This will make sure you are not paying for more capacity than you need and it will ensure the system will properly dehumidify the home and run efficiently.

■ Heat pumps and air conditioners have a Seasonal Energy Efficiency Ratios (SEER) rating of at least 14 and a Heating Season Performance Factor (HSPF) of at least eight. Gas Furnaces for heat, or back up heat, should have a rating of at least 90 AFUE (Annual Fuel Utilization Efficiency). The higher the number the better.

■ Locate ductwork and the mechanical unit in the conditioned space if possible. All ductwork should have an insulating value of R-8. Ductwork should be designed using Manual D.

■ Consider using rigid metal ductwork for increased durability and indoor air quality. Rigid metal is easy to clean and will not trap dust or absorb moisture. Building cavities, such as floor joists, should not be used as part of the forced air supply or return system.

■ All joints/seams in the air distribution system are sealed using fiberglass mesh tape and duct mastic. This includes duct connection to metal boots (in sub floor), trunk lines and air handler units. Insulating liner of ducts must also be sealed with mastic.

■ Indoor and outdoor HVAC units are “matched” according to the ARI Directory or the manufacturer’s listing.

■ Correct charge of refrigerant has been installed per manufacturer’s specifications.

■ Registers and diffusers have proper throw and spread to keep rooms properly conditioned as the load specifies.

■ Duct dampers should be installed and accessible on supply vents. These dampers will make it possible to adjust the flow and spread of air from the registers.

■ Ducts should be sealed and then tested by a Home Energy Rater to have no more than 5 percentage leakage.

■ If you are installing an all-electric heat pump, make sure to install an outdoor thermostat to control when the electric heat strips power on, this will maximize your efficiency.

■ Install a programmable thermostat.