Heating and cooling load calculations
I wanted to get a 2nd opinion from the knowledgeable readers of this site about what an accurate heating/cooling calculation would be for my new house. Both programs I have used(BEOPT and RemDesign trial version) say 18-24,000 btu heating load and 12-14,000 cooling load. I made a spreadsheet and calculated about the same as well.
The builder has received the heating/cooling calculation from his HVAC sub-contractor with a heating loss of 35,000 btus. I was not shown the cooling calculations which I’m more worried about as I’m going with a Hydro-air system with a Phoenix Light duty water heater. All household ventilation will be provided by recoupaerator ERV with a range hood fan while cooking. Heating will be forced air with a fan coil with ECM blower fan. AC will be seer 13. My calculations show 1.5ton of cooling.
The house specs are as follows:
1232 sq ft on each floor(basement-1st-2nd)–all conditioned for this calculation.
8’8″ basement, 14″ floor truss, 9′ first floor, 14″ floor truss, 8′ 2nd floor
Energy heel roof truss with R-60 cellulose insulation
Walls are 2X6, 16″ on center with flash and batt(Proseal ECO and denim batts) with rain screen gap on outside of Tyvek. R16.5
Location- Milwaukee- 53154
2″ of exterior insulation at R-10,
4″ of exterior foundation insulation at R-20
2″ of sub slab insulation at R-10
Windows are at or above R-5( Wasco triple pane,LSGH, Passive house rated windows)- about 220 sq-ft
Patio door is Wasco Tilt-turn triple pane LSHG- r-5 at 40 sq-ft
Two other entrance doors are standard 36″ entrance doors- R-5 at 40 sq-ft
The builder’s most recent Focus on Energy houses have an average of .15 cfm50. Focus on Energy standard is .2. For my house, at .15, would be about 1ach50.
If I missed anything, please let me know, otherwise thanks for the help. This site has provided me a world of knowledge for building my house.
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