1922-2A Heating System Sizing WorksheetSimple Heating System Size: Washington State
Project Information Contact Information
Heating System Type:
To see detailed instructions for each section, place your cursor on the word "Instructions"
Design Temperature
Instructions Design Temperature Difference (∆T)53
∆T = Indoor (70 degrees) - Outdoor Design Temp
Area of Building
Conditioned Floor Area
Instructions Conditioned Floor Area (sq ft)1,922
Average Ceiling Height Conditioned Volume
Instructions Average Ceiling Height (ft)8.0 15,376
Glazing and Doors U-Factor X Area =UA
Instructions 0.280 331 92.62
Skylights U-Factor X Area =UA
Instructions 0.50 ---
Insulation
Attic U-Factor X Area =UA
Instructions 0.026 1,282 33.33
Single Rafter or Joist Vaulted Ceilings U-Factor X Area UA
Instructions ---________
Above Grade Walls (see Figure 1)U-Factor X Area UA
Instructions 0.056 2,334 130.70
Floors U-Factor X Area UA
Instructions 0.025 931 23.28
Below Grade Walls (see Figure 1)U-Factor X Area UA
Instructions 0.028 ---
Slab Below Grade (see Figure 1)F-Factor X Length UA
Instructions 0.303 ---
Slab on Grade (see Figure 1)F-Factor X Length UA
Instructions ---________
Location of Ducts
Instructions Duct Leakage Coefficient
1.00
Sum of UA 279.94
Envelope Heat Load 14,837 Btu / Hour
Sum of UA x ∆T
Air Leakage Heat Load 8,801 Btu / Hour
Volume x 0.6 x ∆T x 0.018
Building Design Heat Load 23,638 Btu / Hour
Air leakage + envelope heat loss
Building and Duct Heat Load 23,638 Btu / Hour
Ducts in unconditioned space: sum of building heat loss x 1.10
Ducts in conditioned space: sum of building heat loss x 1
Maximum Heat Equipment Output 29,547 Btu / Hour
Building and duct heat loss x 1.40 for forced air furnace
Building and duct heat loss x 1.25 for heat pump
This heating system sizing calculator is based on the Prescriptive Requirements of the 2018 Washington State Energy Code (WSEC) and ACCA Manuals J
and S. This tool will calculate heating loads only. ACCA procedures for sizing cooling systems should be used to determine cooling loads.
Please complete the green drop-downs and boxes that are applicable to your project. As you make selections in the drop-downs for each section, some values
will be calculated for you. If you do not see the selection you need in the drop-down options, please contact the WSU Energy Program at
energycode@energy.wsu.edu or (360) 956-2042 for assistance.
1922-2A LEVEL DESIGN LLC
253-284-3170
Above Grade
Below Grade
Figure 1.
All Other Systems Heat Pump
(07/01/13)