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Aquarea air / water heat pump – design handbook 07 / 2014
Project Design
Establishing the heating load and outside design temperature
For existing buildings, the rough calculation method described below can
also be used for establishing the heating load. It should only be used as
an estimate because a variety of factors like house type, insulation and
the ventilation rate play a role in the calculation. Over the years, the
specific heat requirement of buildings has constantly decreased owing
to increasingly stringent thermal insulation requirements. Owing to this
fact, the following rates per square metre living-space are used as
approximation:
Existing buildings before 1977
163 to 250 W / m²
Buildings as from 1977
88 to 163 W / m²
Buildings as from 1982
75 to 125 W / m²
Buildings as from 1995
50 to 75 W / m²
Buildings as from 2002
38 to 63 W / m²
Low energy building
31 to 50 W / m²
Ultra-low energy building
19 to 38 W / m²
Passive house
≤ 13 W / m²
Typical values for the specific heat requirement of residential buildings
for rough calculation of heating load
For a 1992 residential house in London, UK with a living space of 120 m²,
has a required heating load of 12 kW (100 W / m²). The standard outside
design temperature for the residential house can be read from the table
for the considered location with θe = -1.8 ˚C.
The heat pump should therefore approximatley provide the determined
heating capacity of 12 kW for an outside temperature of -1.8 °C.
Example
Note
The above calculation method provides only rough estimated values
for the heating load. For correct dimensioning, precise calculation of
the required heating load must be carried out by a heating system
specialist. Under no circumstances can Panasonic be made responsible
for any miscalculations.
