Insulation reduces heat transfer but does not remove solar and internal gains. Summer comfort needs its own strategy.
Sources of heat
Solar gains, occupants, appliances and hot-water systems add heat. Assess timing as well as daily totals.
West glazing and shading
External shading can limit gains before they pass through the glass. Check solar angles, controls and whether occupants can realistically use it.
Thermal mass
Mass can delay and smooth temperature response but does not eliminate energy. Without heat rejection, its benefit is limited over successive warm days.
Night cooling
Check outdoor temperature, security, noise and window-opening feasibility. An MVHR bypass does not guarantee enough heat removal.
Active cooling
Where passive measures are insufficient, size cooling against the load. Consider humidity, air distribution and noise rather than unit capacity alone.
Early assessment
Test normal and adverse scenarios: more occupants, unavailable night ventilation or unused shading. Unrealistic occupant assumptions can conceal risk.
| Item | Parameter | Check / result |
|---|---|---|
| Gains | Solar + internal | Reduce |
| Storage | Mass | Assess over time |
| Rejection | Night; cooling | Verify availability |
What this means for your project
Request a summer assessment alongside the winter balance. Make the occupant actions needed for the predicted comfort explicit.
Sources and scope of review
Related reading
- House Orientation: What Actually Affects Energy Balance
- Installing Windows in the Insulation Layer
- Heat Pumps in Low-Energy Homes