Komfovent 1300 U, Руководство по установке

Страница: 8 / 36

8
UAB KOMFOVENT we reserve the right to make changes without prior notice
RHP STANDARD_21-04
EN
Heat pump model and exact refrigerant load capacity is stated on the sticker, that can be found inside of AHU:
Air handling unit model / Vėdinimo įrenginio modelis RHP 600 U
Heat pump model / Šilumos siurblio modelis HP 4.4/3.8
Maximum operating pressure
Maksimalus darbinis slėgis
P
max
[bar] 20
Refrigerant / Šaltnešis R134A
Number of circuits / Kontūrų skaičius 1
Quantity of refrigerant / Šaltnešio kiekis m
R134A
[kg] 2,08
Fig. 3 Example of a heat pump's information label
Heat pump is activated automatically when a rotary heat exchanger is unable to reach desired temperature; and is
switched off as soon as desired temperature is reached. Frequent starting and stopping of a heat pump may damage com-
pressor, therefore, when heating/cooling demand is low, the heat pump will continue running for some time after the set
temperature has been reached. In such cases, supplied air may be slightly warmer (in heating mode) or cooler (in cooling
mode) than desired; however, the extracted temperature control mode will help to reduce such temperature fluctuations
(see “User Instructions”).
A certain airflow is required to ensure proper operation of a heat pump, i. e. to ensure efficient heat exchange and main-
tain refrigerant pressure within limits. When airflow drops below a minimum limit, a heat pump temporarily stops. Operation
is resumed only when airflow increases. The table below shows the minimum airflows required for heat pump operation that
must be taken into account when designing the ventilation system and selecting additional functions:
Unit model Minimum air flow
RHP 400 U-2.8/2.4 250
RHP 600 U-3.7/3 250
RHP 600 U-4.4/3.8 400
RHP 800 U-5.3/4.7 400
RHP 800 U-6.1/5.8 600
RHP 1300 U-8.1/6.6 600
Heat pump is not operating when outdoor air temperature is between 15°C and 20°C, as, in this case, the rotary heat
exchanger is usually capable of reaching desired air temperature.
If heating/cooling demand increases when the heat pump is switched off, additional heaters/coolers are activated
1
.
When the heat pump is running, we recommend operating air handling units with the smallest pos-
sible air volume difference between the supply and extract airflows. In case of high flow imbalances
(>20%), capacity and efficiency of the heat pump decreases, therefore the compressor operates at
a critical refrigerant pressure limit. This results in reduced operating life and increased probability of
failure.
During winter operation, when the heat pump is in heating mode, condensate on the evaporator starts freezing and
forms frost. Large ice deposits block airflow in the evaporator and may damage the heat pump. Therefore, the evaporator
is automatically defrosted during winter use. When the outdoor temperature drops below zero, the heat pump automation
system starts constantly monitoring pressure difference upstream and downstream the evaporator heat exchanger. When
condensate accumulates in heat exchanger plates and ice starts to form, pressure increases and defrosting actions are initi-
ated. During the defrost cycle, part of the hot refrigerant gas is directed from the compressor to the evaporator to melt for-
ming ice crystals, therefore supply air temperature temporarily drops. Integrated electric or auxiliary heaters are switched on
to compensate for this change. As soon as frost melts and pressure decreases, all the power of the heat pump is redirected
to the heating process.
1 Depends on configuration.