Home Insulation R-Value Calculator — NH Climate Zone Heat Loss Estimator
Calculate heat loss through your building envelope and get recommended R-values based on New Hampshire's climate zones (Zone 5 and Zone 6). Uses ASHRAE 99% design temperatures and IRC 2021 insulation requirements.
Formulas Used
Thermal Conductance (UA):
UA = (1/R) × Area [BTU/hr·°F] for opaque assemblies
UA = U-factor × Area [BTU/hr·°F] for windows and doors
Peak Heat Loss:
Qpeak = UAtotal × ΔT [BTU/hr]
where ΔT = Tindoor − Toutdoor,design
Annual Heat Loss:
Qannual = UAtotal × HDD65 × 24 [BTU/yr]
Annual Heating Cost:
Cost = (Qannual [MMBtu] / η) × $/MMBtu
Assumptions & References
- Recommended R-values per IRC 2021 Table N1102.1.3 for Climate Zones 5 and 6.