Heating load in Fort Bragg
A home in Fort Bragg has to be heated against a design temperature of −7.6 °C. That figure is measured, not modelled: it is the 1st percentile of daily minimum temperature over 25 years at Pope Afb Airport, 4 km away.
Design temperature
−7.6 °C
Heating degree days
1,095
Coldest month
Jan
Coldest night on record
−16.2 °C
Coldest station in range
−9.0 °C
How many kilowatts
Heating power needed at the design temperature, in kilowatts, for a detached house. Pick the row that matches the building.
| Construction | Detached | Semi-detached | Terraced | Top-floor flat | Mid-floor flat | Ground-floor flat |
|---|---|---|---|---|---|---|
| Uninsulated, single glazed | 17.8 kW | 15.6 kW | 13.8 kW | 15.2 kW | 7.4 kW | 9.1 kW |
| Unfilled cavity, early double glazing | 12.0 kW | 10.4 kW | 9.1 kW | 8.8 kW | 5.3 kW | 6.7 kW |
| Insulated to 1980s standards | 6.9 kW | 6.2 kW | 5.6 kW | 5.3 kW | 3.8 kW | 4.9 kW |
| Modern, roughly 1995-2010 | 4.2 kW | 3.9 kW | 3.6 kW | 3.4 kW | 2.6 kW | 3.1 kW |
| Current building regulations | 3.2 kW | 3.0 kW | 2.8 kW | 2.7 kW | 2.0 kW | 2.4 kW |
| Passive house | 1.9 kW | 1.7 kW | 1.6 kW | 1.5 kW | 1.0 kW | 1.4 kW |
Where the heat goes
For a 120 m2 detached house of this construction, at the design temperature.
| Element | W | Share |
|---|---|---|
| Walls | 2,267 | 33% |
| Roof | 662 | 10% |
| Ground floor | 447 | 7% |
| Windows | 1,292 | 19% |
| Thermal bridges | 379 | 6% |
| Ventilation and draughts | 1,830 | 27% |
| Heating load | 6,878 | 6.9 kW |
Calculate it for your own home
The climate half of this is measured. The building half is yours to supply.
Monthly mean temperature
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| °C | 6.5 | 8.1 | 11.9 | 17.3 | 21.5 | 25.5 | 27.3 | 26.2 | 23.2 | 17.2 | 11.2 | 7.9 |
Where these numbers come from
- Measured: the design temperature, the degree days and the monthly means. All of it from one station, Pope Afb Airport, over 25 complete years.
- Assumed: everything about the building. The U-values are typical published figures for each construction era, not a survey of your house. Two houses of the same age and size can differ by a factor of two.
- No credit is taken for sunshine or for the heat given off by people and appliances. That is the EN 12831 convention, because the design condition is a still, dark night.
- This is space heating only. Domestic hot water is a separate load.
- This is a calculation, not a survey. Before spending money, have the building assessed.