23.04.2014
18 / 21
8
Frequently asked questions regarding operation
Several issues involved in the heat pump operation have been distinguished on the basis previous questions from our clients:
1) Is it better if the pump works during second (cheaper) tariff of electricity charge, or during regular tariff in daytime, when
outside air is warmer (provided that we take air for the pump from outside)?
There is no significant difference in operating costs, because in this case lower price of electric energy is also connected with
lower temperature of supply air at night. In case of heat pump connected to exhaust air from ventilation, in fact it is possible to
heat up the tank at lower cost overnight.
2) Is it possible to use colder exhaust air from the heat pump to cool a building?
Yes, however in case of larger distances it is necessary to use an additional fan to support air flow, tubes should be fitted to
ventilation system requirements and, much the same as in air-conditioners, evaporator should undergo antibacterial cleaning at
least once per year.
3) What is the condensate?
The condensate is condensed steam generated due to cooling of air flowing through the evaporator. It is a most desired effect,
because considerable volume of heat is transferred to cooling medium during condensation. As a result of this, the COP
coefficient value depends not only on ambient temperature, but on air humidity as well.
4) Is it possible to connect the PCWU 2.5kW heat pump to air conditioning station (that is work with ventilation air)?
Yes, however we should remember that the heat pump air demand reaches 350-500 m³/h. In case of work with ventilation air
the heat pump may operate all-year-round at efficiency index near 4.
5) Is it possible to unplug the unit if for example we use boiler in wintertime?
Due to the heat pump safeguards, which must be connected to power network, it is not allowed to cut off power supply of the
whole unit. In such case it is possible to switch off the heat pump from the controller level.
6) How many litres of water can be heated up within 1 hour?
A lot depends on the temperature of heated water and temperature of air drawn into the heat pump. Average volume of heated
up water ranges from 40 to 80 litres per hour.
7) Can I use this equipment to heat building?
The heat pump power has been selected so as to match utility water heating needs. We should remember that the heat pump
power drops at lower temperatures.
8) Which are minimum temperatures the PCWU 2.5kW heat pump may work at?
Minimum working temperature set at the controller is -5°C. However, its work under 0°C may result in faster wear and tear of the
compressor. Minimum working temperature should be set depending on second water heating source.
