Unical ENERPUMP DHW 110, Installation And Service Manual

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Luxury Air Source Heat Pump-Monobloc System 31
Checking the water volume and expansion vessel pre-pressure
The unit is equipped with an expansion vessel of 10 liters which has a default pre-pressure of 1 bar.
To assure proper operation of the unit, the pre-pressure of the expansion vessel might need to be
adjusted and the minimum and maximum water volume must be checked.
1. Check that the total water volume in the installation is 32 L minimum.
IN MOST AIR CONDITIONING APPLICATIONS THIS MINIMUM WATER VOLUME WILL HAVE A
SATISFYING RESULT. IN CRITICAL PROCESSES OR IN ROOMS WITH A HIGH HEAT LOAD THOUGH,
EXTRA WATER VOLUME MIGHT BE REQUIRED
2. Using the table below, determine if the expansion vessel pre-pressure requires adjustment.
3. Using the table and instructions below, determine if the total water volume in the installation is
below the maximum allowed water volume.
Water volume Installation
height
difference (a)
≤ 460 L
＞
460 L
≤ 7 m No pre-pressure adjustment
Required.
Actions required:
pre-pressure must be decreased, calculate according to
“calculating the pre-pressure of the expansion vessel”
check if the water volume is lower than maximum
allowed water volume (use graph below)
> 7 m
Actions required:
pre-pressure must be increased,
calculate according to “calculating the
pre-pressure of the expansion vessel”
check if the water volume is lower than
maximum allowed water volume (use graph
below)
Expansion vessel of the unit too small for the
installation.
(a) Installation height difference: height difference (m) between the highest point of the water circuit and the indoor unit. If the
indoor unit is located at the highest point of the installation, the installation height is considered 0 m.
Calculating the pre-pressure of the expansion vessel
The pre-pressure (Pg) to be set depends on the maximum installation height difference (H) and is
calculated as follows:
Pg = (H/10+0.3) bar
Checking the maximum allowed water volume
To determine the maximum allowed water volume in the entire circuit, proceed as follows:
1. Determine for the calculated pre-pressure (Pg) the corresponding maximum water volume using the
graph below.
2. Check that the total water volume in the entire water circuit is lower than this value.
If this is not the case, the expansion vessel inside the indoor unit is too small for the installation.