Heat Pump Balance Point
Balance temperature from heating capacity and heat loss.
Example
You enter
- Heating capacity at design (BTU/hr) 30000
- Design outdoor temperature (°F) 17
- Building heat loss (BTU/hr) 50000
- Indoor design temperature (°F) 65
You get
- Balance point 31.9 F
Details, formula, and sources
Outdoor temperature at which heat-pump heating capacity equals the building heat-loss line. Solve C_design × (T_in − T_bp) = HP_capacity(T_bp) by interpolation across the manufacturer capacity-vs-OAT table.
ACCA Manual J, 8th edition. manufacturer heat-pump capacity tables by name.
Manufacturer capacity tables free on each manufacturer site.
Estimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.
Field names used by the API: heating_capacity_btu_hr_at_design, design_outdoor_F, building_heat_loss_btu_hr, indoor_F, balance_point_F
- Heat-loss line linear in (T_in − T_outdoor) per Manual J conventionACCA Manual J 8th ed.