2021.0011 D1320-1-1320-1 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)1,320
Average Ceiling Height Conditioned Volume
Instructions Average Ceiling Height (ft)8.5 11,220
Glazing and Doors U-Factor X Area =UA
Instructions 0.280 234 65.46
Skylights U-Factor X Area =UA
Instructions 0.50 0 ---
Insulation
Attic U-Factor X Area =UA
Instructions 0.026 818 21.27
Single Rafter or Joist Vaulted Ceilings U-Factor X Area UA
Instructions ---0 ________
Above Grade Walls (see Figure 1)U-Factor X Area UA
Instructions 0.056 1,998 111.89
Floors U-Factor X Area UA
Instructions 0.025 818 20.45
Below Grade Walls (see Figure 1)U-Factor X Area UA
Instructions 0.028 0 ________
Slab Below Grade (see Figure 1)F-Factor X Length UA
Instructions 0.303 0 ---
Slab on Grade (see Figure 1)F-Factor X Length UA
Instructions ---0 ________
Location of Ducts
Instructions Duct Leakage Coefficient
1.10
Sum of UA 219.07
Envelope Heat Load 11,611 Btu / Hour
Sum of UA X ∆T
Air Leakage Heat Load 6,422 Btu / Hour
Volume X 0.6 X ∆T X .018
Building Design Heat Load 18,033 Btu / Hour
Air Leakage + Envelope Heat Loss
Building and Duct Heat Load 19,836 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 27,771 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 2015 Washington State Energy Code (WSEC) and ACCA
Manuals J and S. This calculator will calculate heating loads only. ACCA procedures for sizing cooling systems should be used to determine cooling
loads.
Please fill out all of 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 call the WSU Energy Extension
Program at (360) 956-2042 for assistance.
D1320-1-1320-1 LEVEL DESIGN LLC
253 284-3170
Above Grade
Below Grade
Figure 1.
All Other Systems Heat Pump
(07/01/13)