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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
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