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Aquarea air-to-water heat pumps - Planning and installation manual - 02/2022
Planning
5
ATTENTION
Risk of damage to building or of slipping on the floor
In cooling mode, a temperature drop below dew point can cause condensation of moisture from the
air on the surface of the heat transfer systems. This can damage the building or pose the risk of
slipping on the floor.
►
Prevent the temperature from dropping below the dew point by suitable placement of dew
point sensors.
►
Alternatively, safely drain the condensate that forms.
► In addition, insulate the pipes concerned to prevent diffusion.
5.1.7.1 Cooling with underfloor heating
Underfloor heating (or any surface embedded heating system) is generally suitable for the cooling
mode, however cannot be operated with very low supply water temperatures, because the level
of comfort drops, and the danger of falling below the dew point arises. In general, therefore, the
surface temperature should be limited to at least 20 °C. If the temperature difference between
supply and return water temperature (ΔT) is 3 to 4 K, it is possible to achieve a specific cooling
capacity of 30 to 40 W / m². The cooling capacity is influenced considerably by the pipe distance
and the pipe diameter of the underfloor heating as well as the floor covering. In the case of a tiled
floor, the heat transfer is significantly better than, say, with a carpeted floor, which directly affects
the cooling capacity.
Due to the systemic limits to the cooling capacity of underfloor heating, room cooling cannot be
regulated to a fixed indoor temperature. However, at least the supply water temperature must be
set to a value that prevents the room temperatur from dropping below dew point.
5.1.7.2
Cooling with fan coils
Fan coils can be operated with very much lower supply water temperatures than underfloor
heating. Correspondingly, fan coils allow you to achieve a higher cooling capacity than underfloor
heating and also greater comfort due to the type of room climate control. Due to the low supply
water temperatures, which can be obtained when using fan coils for room cooling, the pipe must be
covered by a diffusion-proof insulation and the condensate must be drained via a connection pipe
to the house drainage system or to the outside.
5.2 Installation criteria
5.2.1 Acoustics
5.2.1.1 Sound pressure level
Sound is produced when air is made to start vibrating. This vibration widens as a pressure wave
in the air and this way travels from the sound emission source to the eardrum of the human
ear (immission point). Irrespective of the type of sound (language or engine sound), the sound
can be measured as sound pressure. The higher the sound pressure, the louder is the sound
perception. The human ear can perceive a range from 20 x 10
-6
Pa (audible threshold) to 20 Pa
(pain threshold). This range, which corresponds to a ratio of 1:1,000,000, is however not perceived
by the human ear in a linear manner, but a logarithmic one. For this reason, the sound pressure is
also not indicated as pressure but as a sound pressure level in Decibels (dB).
Typical sound situations and thereby occurring sound pressure levels and sound pressures
Sound
Sound pressure level in
dB (A)
Sound pressure in μPa
Sensitivity
Woods
20
100
Very soft
Library
40
1,000
Soft
