Internal sensible and latent loads
Heat loads exist within buildings due to latent heat energy of moisture in the air, human activity (people are a source of heat energy), and non-thermal comfort related energy consumption. Base heat loads are defined in NatHERS to include heat generated from cooking, lighting, electrical appliances and from people. These loads are applied according to the primary function or functions of the room (such as cooking or sleeping), and the time of day a room is expected to be used.
The heat loads in the following table are for a 160 m2 dwelling with two adults and two children, with a floor area split of 80 m2 for all the living areas and 80 m2 for all the bedroom areas. Suitable adjustments should be made for houses with different total areas, and for individual spaces with different areas. The load is for the one hour period up to the time stated i.e. a time of 1:00 am indicates the period between midnight and 1:00 am.
| For living spaces, including kitchens | |||||
|---|---|---|---|---|---|
| Time | Sensible heat load (Watts) | Latent heat load (Watts) |
|||
| Appliances and cooking |
Lighting | People | Total | ||
| 1:00 am | 100 | 0 | 0 | 100 | 0 |
| 2:00 am | 100 | 0 | 0 | 100 | 0 |
| 3:00 am | 100 | 0 | 0 | 100 | 0 |
| 4:00 am | 100 | 0 | 0 | 100 | 0 |
| 5:00 am | 100 | 0 | 0 | 100 | 0 |
| 6:00 am | 100 | 0 | 0 | 100 | 0 |
| 7:00 am | 100 | 0 | 0 | 100 | 0 |
| 8:00 am | 400 | 180 | 280 | 860 | 400 |
| 9:00 am | 100 | 180 | 280 | 560 | 200 |
| 10:00 am | 100 | 0 | 140 | 240 | 100 |
| 11:00 am | 100 | 0 | 140 | 240 | 100 |
| Noon | 100 | 0 | 140 | 240 | 100 |
| 1:00 pm | 100 | 0 | 140 | 240 | 100 |
| 2:00 pm | 100 | 0 | 140 | 240 | 100 |
| 3:00 pm | 100 | 0 | 140 | 240 | 100 |
| 4:00 pm | 100 | 0 | 140 | 240 | 100 |
| 5:00 pm | 100 | 0 | 140 | 240 | 100 |
| 6:00 pm | 100 | 300 | 210 | 240 | 150 |
| 7:00 pm | 1100 | 300 | 210 | 1610 | 750 |
| 8:00 pm | 250 | 300 | 210 | 760 | 150 |
| 9:00 pm | 250 | 300 | 210 | 760 | 150 |
| 10:00 pm | 250 | 300 | 210 | 760 | 150 |
| 11:00 pm | 100 | 0 | 0 | 100 0 | |
| Midnight | 100 | 0 | 0 | 100 0 | |
| For living spaces that do not include a kitchen | |||||
|---|---|---|---|---|---|
| Time | Sensible heat load (Watts) | Latent heat load (Watts) |
|||
| Appliances and cooking |
Lighting | People | Total | ||
| 1:00 am | 0 | 0 | 0 | 0 | 0 |
| 2:00 am | 0 | 0 | 0 | 0 | 0 |
| 3:00 am | 0 | 0 | 0 | 0 | 0 |
| 4:00 am | 0 | 0 | 0 | 0 | 0 |
| 5:00 am | 0 | 0 | 0 | 0 | 0 |
| 6:00 am | 0 | 0 | 0 | 0 | 0 |
| 7:00 am | 0 | 0 | 0 | 0 | 0 |
| 8:00 am | 0 | 180 | 280 | 460 | 140 |
| 9:00 am | 0 | 180 | 280 | 460 | 140 |
| 10:00 am | 0 | 0 | 140 | 140 | 70 |
| 11:00 am | 0 | 0 | 140 | 140 | 70 |
| Noon | 0 | 0 | 140 | 140 | 70 |
| 1:00 pm | 0 | 0 | 140 | 140 | 70 |
| 2:00 pm | 0 | 0 | 140 | 140 | 70 |
| 3:00 pm | 0 | 0 | 140 | 140 | 70 |
| 4:00 pm | 0 | 0 | 140 | 140 | 70 |
| 5:00 pm | 0 | 0 | 140 | 140 | 70 |
| 6:00 pm | 0 | 300 | 210 | 510 | 105 |
| 7:00 pm | 0 | 300 | 210 | 510 | 105 |
| 8:00 pm | 0 | 300 | 210 | 510 | 105 |
| 9:00 pm | 0 | 300 | 210 | 510 | 105 |
| 10:00 pm | 0 | 300 | 210 | 510 | 105 |
| 11:00 pm | 0 | 0 | 0 | 0 | 0 |
| Midnight | 0 | 0 | 0 | 0 | 0 |
| For bedrooms | ||||
|---|---|---|---|---|
| Time | Sensible heat load (Watts) | Latent heat load (Watts) |
||
| Lighting | People | Total | ||
| 1:00 am | 0 | 200 | 200 | 100 |
| 2:00 am | 0 | 200 | 200 | 100 |
| 3:00 am | 0 | 200 | 200 | 100 |
| 4:00 am | 0 | 200 | 200 | 100 |
| 5:00 am | 0 | 200 | 200 | 100 |
| 6:00 am | 0 | 200 | 200 | 100 |
| 7:00 am | 0 | 200 | 200 | 100 |
| 8:00 am | 0 | 0 | 0 | 0 |
| 9:00 am | 0 | 0 | 0 | 0 |
| 10:00 am | 0 | 0 | 0 | 0 |
| 11:00 am | 0 | 0 | 0 | 0 |
| Noon | 0 | 0 | 0 | 0 |
| 1:00 pm | 0 | 0 | 0 | 0 |
| 2:00 pm | 0 | 0 | 0 | 0 |
| 3:00 pm | 0 | 0 | 0 | 0 |
| 4:00 pm | 0 | 0 | 0 | 0 |
| 5:00 pm | 0 | 0 | 0 | 0 |
| 6:00 pm | 0 | 0 | 0 | 0 |
| 7:00 pm | 0 | 0 | 0 | 0 |
| 8:00 pm | 100 | 0 | 100 | 0 |
| 9:00 pm | 100 | 0 | 100 | 0 |
| 10:00 pm | 100 | 0 | 100 | 0 |
| 11:00 pm | 100 | 200 | 300 | 100 |
| Midnight | 0 | 200 | 200 | 100 |