Southwest HVAC News
Undersized HVAC Equipment – Neither makes for a Comfortable
Many contractors think a bigger system will reduce the number of
complaints they get. Or the HVAC unit may be oversized because you
have added insulation or double-pane windows and the contractor just
replaces your old inefficient system with a new efficient system of
the same size. What good is it to you when your HVAC system
constantly turns on and off (short-cycling) and everyone is hot and
clammy because the unit isn’t on long enough to remove the humidity?
What a waste of energy!
Though under sizing heating and cooling equipment is not as big a
problem, the symptoms are running continuously and it does not cool
the area. What good is a system that works that hard and fails? What
a waste of money!
You are about to invest thousands of dollars of YOUR hard earned
money and you expect it to provide proper comfort for you and your
family for many years to come. But if you purchase an improperly
sized HVAC system, it will not keep you comfortable and it will not
last for years.
ACCA Manual J – Sizing your heating and cooling system the right
You must commission a qualified HVAC designer to calculate the
needed heat gain and heat loss for your specific home. The only
“correct” method for sizing HVAC equipment is called ACCA Manual J8
load calculation. Not just put in the same size system as the old
one or, worse yet, use some archaic method such as “rule of thumb”
of 1 ton = 400 sq ft.
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Have an accurate
Manual J performed based on your home’s specific design. Below
are just a few of many parameters analyzed:
•What direction does your front door face?
•What kind of windows do you have?
•What kind of wall and ceiling insulation?
•Where do you live? ◦How cold are your winters?
◦How hot are your summers?
ACCA Manual J is the ONLY way to correctly size your air
conditioner and furnace. Once these calculations are completed,
your HVAC contractor will select the Right-Sized equipment for
your home’s heating and cooling loads.
We at Savoy Engineering Group utilize the ACCA certified
software WrightSoft Universal and have performed thousands of
Manual J load calculations, Manual S equipment selection and
Manual D duct designs throughout the United States. We have a
100% PASS rate with all permit offices, LEED, HERSRaters,
EnergyStar and CALGreen programs.
ACCA Manual J Load Calculation and ACCA Manual D Duct Design
Engineering Service using ACCA Certified WrightSoft Residential