Verified Climate Data • Zip 98101
HVAC Load Calculator for
Seattle Homes
Summer Design81°F
Winter Design31°F
Humidity Loadmedium
Local Climate Analysis for Seattle
Seattle typically experiences summer highs reaching design temperatures of 81°F. With moderate humidity, standard sizing rules apply, but insulation quality remains critical.
📊 Energy Usage Profile
Cooling Demand (CDD)372
Days you need AC
Heating Demand (HDD)4847
Days you need Heat
⚙️ Technical Factors
Wet Bulb60°F
Standard humidity management sufficient.
Elevation184 ft
No derating needed.
Manual J Tip for WA
Because the design temperature difference (Delta T) in Seattle is approximately 6°F (Summer) and 39°F (Winter), your system may need to be sized primarily for one extreme season over the other.
Installation Cost in Seattle
Local labor rates and equipment standards in WA influence the final quote. For a standard 3-ton system changeout in Seattle, calculate roughly $1,800 - $2,200 per toninstalled, depending on whether you choose a single-stage or variable-speed inverter unit.