Panasonic Aquarea WH-SDC07H3E5-1 - Cooling; 25 5.1.7.2 Cooling with Fan Coils; Installation Criteria; Acoustics

86 Aquarea air-to-water heat pumps - Planning and installation manual - 01/2018
Planning
87
Aquarea air-to-water heat pumps - Planning and installation manual - 01/2018
Planning
5.1.7 Cooling
Aquarea heat pump models with cooling function are switched over manually from heating
mode to the cooling mode and must be switched back to the heating mode after completing the
cooling period.
CAUTION
Danger of damage to building or risk of slipping in the oor area
In the cooling mode, a 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 in the oor area.
► Prevent the temperature from dropping below the dew point by suitable placement of
dew point sensors.
► Alternatively, the condensate that forms can be safely diverted.
► In addition, insulate the pipelines concerned to prevent diffusion.
5.1.7.1 Cooling with Underoor Heating
Underoor heating is generally suitable for the cooling mode, however cannot be operated with
very low water inow temperatures, because the level of comfort drops, and the danger of falling
below the dew point arises. In general, therefore, the surface temperature is limited to at least
20 °C. If the spread of the water inow and water return temperature is from 3 to 4 K, it is pos-
sible to achieve a specic cooling capacity of 30 to 40 W / m². The cooling capacity is inuenced
considerably by the pipe distance and the tube diameter of the underoor heating as well as the
oor covering. In the case of a tiled oor, the heat transfer is distinctly better than, say, with a
carpeted oor, which directly affects the cooling capacity.
Based on the system limits of cooling capacity of underoor heating, room cooling cannot be
regulated to a xed indoor temperature. At least the water inow temperature must be set that
prevents falling below the dew point.
5.1.7.2 Cooling with fan coils
Fan coils can be operated with very much lower water inow temperatures than underoor
heating. Correspondingly, fan coils allow you to achieve higher cooling capacity than underoor
heating and also greater comfort due to the type of room climate control. Due to the low water
inow temperatures, a diffusion-proof insulation of the pipeline as well as connection of the
condensate discharge to the house drainage system or discharge of the water condensation to
outside must be considered when using fan coils for room cooling.
5.2 Installation criteria
5.2.1 Acoustics
5.2.1.1 Sound pressure level
Sound is produced if air is set in vibration. This vibration widens as a pressure wave in the air
and this way reaches from emission source to the ear drum of the human ear (immission sort).
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 indicat-
ed 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
Conversation 55 10,000 normal
Road 80 100,000 Loud
Press air hammer 100 1,000,000 Very loud
The result of the non-linear perception of the sound pressure is that two equally loud sound
sources are not perceived doubly as loud as one sound source, but only as 3 dB. Doubling the
sound intensity (volume) of a sound is linked to a sound pressure level increase by 10 dB.
The measurable sound pressure level, which is converted to take into account other factors
such as sounds containing pitch in a rating level, are decisive for maintaining the limit values.
This must not exceed the valid immission guide values for immission types outside buildings
(example of Germany: Technical instructions for protection against noise) (TA noise)).
Example of Germany: Immission Guide Values according to TA Noise
Industrial Areas During day and night 70 dB(A)
Commercial areas
Days 65 dB(A)
Nights 50 dB(A)
Business zones
Days 60 dB(A)
Nights 45 dB(A)
General residential zones
Days 55 dB(A)
Nights 40 dB(A)
Purely residential areas
Days 50 dB(A)
Nights 35 dB(A)
Spa areas, hospitals
Days 45 dB(A)
Nights 35 dB(A)