Chart boundary

Does not size a heat pump, calculate heat loss, approve backup heat, or replace HVAC design.

balance point curve

Capacity crosses heat loss

The useful chart is the crossing point: when house heat loss exceeds heat pump capacity, supplemental heat may enter the discussion.

Scopeheating and hvacX-axisoutdoor temperature CY-axiscapacity and heat loss kWReviewAnnualNextHeat pump electric backup load impact chart
Capacity crosses heat lossoutdoor temperature Coutdoor temperature Ccapacity and heat loss kWcapacity and heat loss kWHeat loss curveHeat loss curverises as temperature fallsrises as temperature...Heat pump capacityHeat pump capacityfalls in cold weatherfalls in cold weatherBalance pointBalance pointcurves crosscurves crossBackup regionBackup regionshaded cold bandshaded cold band
The useful chart is the crossing point: when house heat loss exceeds heat pump capacity, supplemental heat may enter the discussion.
Capacity crosses heat lossbalance pointbalance pointbackup regionbackup regionbuilding heat lossbuilding heat...heat pump capacityheat pump capa...outdoor temperature Coutdoor temperature Ccapacity and heat loss kWcapacity and hea...
Heat loss curverises as temperature falls

Building envelope controls the slope.

Heat pump capacityfalls in cold weather

Equipment data controls the curve.

Balance pointcurves cross

Below this point supplemental strategy may matter.

Backup regionshaded cold band

Electrical impact belongs in the backup-load chart.

Decision table

Explain the balance-point curve concept before electrical load and backup heat checks.

Scroll sideways to keep row labels aligned with hidden columns.

Basis: NRCan heat pump resources and Canadian ASHP sizing and selection guides.
Curve bandWhat it showsRisk cueHandoff
Above balance pointHeat pump can cover the building loadLow backup heat useHVAC sizing data
Near balance pointCapacity and heat loss are closeComfort and control strategy matterContractor review
Below balance pointSupplemental heat may be neededElectrical backup load can be largeBackup load impact chart
Notes
  • Treat this chart as a planning and conversation aid only.
  • Confirm current utility requirements, product markings, manufacturer instructions, and local authority requirements before field work.
  • Use the linked calculator or table when the task needs project-specific arithmetic.

Source links

Open the underlying public sources before treating the chart as project guidance.