It is estimated that 80% of homes built before 2004 in the Phoenix metro area have oversized air conditioners or heat pumps. If the unit is over sized, your environment will not be comfortable and it will not work during higher humidity. This also causes a higher utility bills by running a larger unit. HVAC performance and efficiency is contingent upon the calculations of your home’s load, HVAC system sizing and ductwork design. If one area is calculated or assessed inaccurately, your entire system will suffer, as will your comfort and energy budget. Here’s how the pros ensure you receive a wise investment:
Calculating the Home’s Load
A home’s load is calculated using industry standard Manual J from the Air Conditioning Contractors of America (ACCA). Dozens of measurements, assessments and calculations are entered into the Manual J software program to determine the room-by-room load of your home. Some of the more common assessments involve your home’s orientation to the sun, square footage, ceiling height, insulation R-values, air tightness, building materials and much more.
HVAC System Selection
Once your HVAC pro has determined your home’s load, the figures are used with Manual S to determine the correct HVAC system size to install. Correct sizing is important for system performance, efficiency and comfort. If the unit is too large, you’re wasting purchase money and your unit will wear out before its time. If your new system is too small, it won’t be able to consistently keep your home at a comfortable temperature. Parts will be stressed and fail early, and your system will be noisier operating at full capacity.
The size of your ductwork depends on the output of the blower motor. Correct duct sizing is just as important as correctly sizing your HVAC system. Ducts that are too small make a lot of noise and hinder efficient heating and cooling. Ducts that are too large won’t provide enough air pressure to your living space.
Ducts should be tightly sealed with screws, mastic and foil-backed tape. When possible, locate ducts inside the conditioned spaces in your home. Any ducts located in unconditioned spaces, such as the attic or basement, should be insulated to block heat gain/loss.
To maximize your investment and enjoy peak HVAC performance and efficiency, please contact Wolff Mechanical today. We serve residents in Central Arizona.
Our goal is to help educate our customers in the Phoenix Valley area of Arizona about energy and home comfort issues (specific to HVAC systems).
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