Replacing a home’s air conditioner, heat pump or furnace can make a world of difference in comfort on hot summer days and brisk winter nights. No matter how advanced a new system might be, never assume the old or existing unit has the proper capacity. Correct selection and HVAC installation are essential to ensure the equipment can reach maximum energy efficiency and lifespan. Enjoy lower energy bills and avoid premature wear and breakdowns by being informed about sizing, duct performance, refrigerant charge, and installation clearance.
Proper system size affects both energy consumption and comfort. Too small and the system won't have the capacity to keep you cool on the hottest days. Too big and you'll have temperature swings, hot and cold spots, lingering humidity, and high energy bills.
To determine the optimal size of a system, the technician will first follow the Air Conditioning Contractors of America (ACCA)Manual J to calculate a home's heating and cooling load. Manual J requires collecting data on your home and lifestyle.
Even though most building codes require these calculations, some contractors skip Manual J, which often results in oversized equipment selection.
After Manual J, the contractor should follow Manual S for residential equipment selection. Manual S selects the best equipment for each home. Many installation services leave out Manual J and S calculations to have a lower sales price, but the result for the consumer is less comfort and higher power bills.
Optimal Duct Performance
Equipment relies on your home's ductwork to deliver conditioned air to each room. Money spent improving and correcting the duct system will enhance comfort and increase long-term savings. To ensure your duct system design and size are optimal, the contractor will use Manual D.
Finally, the contractor will inspect your system to ensure it is airtight. Leaky ducts are common and can waste up to 30 percent of conditioned air, cause humidity, rot, and higher power bills. Ductwork leaks can be sealed with duct mastic or heat-safe tape.
Precise Refrigerant Charge
For optimal performance, each air conditioner or heat pump requires an exact amount of refrigerant. A system with a low refrigerant charge will suffer from reduced cooling capacity, low energy efficiency and compressor wear.
Too much refrigerant causes incorrect operating pressures and refrigerant "slugging," which can destroy a compressor. A responsible contractor will check the refrigerant charge after installation, and although it can increase HVAC installation costs, it will reduce power bills.
A system's outdoor condenser unit needs sufficient space around it to release the heat it receives from a home. In most cases, a manufacturer's installation instructions state the required clearance distances. A contractor should use good judgment and make sure the unit is installed clear of roofs or eaves to prevent rain runoff, and, in cold climates, prevent snow or ice from falling on the condenser.
Following these principles will ensure your new HVAC system performs efficiently, while keeping your family comfortable.