For heat pumps and monoblocs
Don't forget the insulation! An uninsulated heat exchanger gives off heat into the room, and in low-temperature mode condensate builds up on the casing.
In a monobloc air-to-water heat pump, the plate heat exchanger separates the outdoor glycol circuit from the clean water of the house. If the power fails or circulation stops, the outdoor piping does not freeze, and there is no need to buy glycol for the house system.
This section contains copper-brazed plate heat exchangers suitable for heat pump systems: Hexonic LB31 and LB60, Danfoss XB12L, Alfa Laval CB20 and CB60. For each model you will find the number of plates, the connection size and the price.
For heating, hot water or both
The same models suit both tasks, but they are selected differently:
- For heating - the glycol circuit is separated from the house heating system. For underfloor heating the temperature difference between the circuits is large, so a smaller heat exchanger is enough. For radiator mode, where the water is heated almost to the glycol temperature, a considerably larger one is needed.
- For hot water - instantaneous preparation requires high short-term capacity, so the heat exchanger is chosen by the peak water flow rate, not by the pump capacity. A larger area than for heating is usually needed here.
- For both - one heat exchanger for both tasks is selected for the more demanding of them, and the circuits are switched with a three-way valve.
Therefore, always state in your enquiry which task the heat exchanger is for - the same model may have a 65% capacity reserve in one mode and none at all in the other.
What is needed for selection
- heat pump capacity, kW;
- supply and return temperatures of both circuits;
- glycol concentration (most often 35%);
- permissible pressure drop, if the pump has already been selected.
A heat exchanger is selected not by kilowatts but by how close the temperatures of the circuits are. The same 15 kW capacity, depending on the mode, requires 1.2 m² or 1.7 m² of area - a difference of 42%. How this works and which mistakes cost the most are described in the article Selecting a heat exchanger for a monobloc or heat pump.
Not sure which to choose? Fill in the enquiry form below - state the capacity, the temperatures of both circuits and the glycol concentration. We will run the calculation in the CAIRO software and give you a specific model with the price and delivery time. We reply within one business day.
Telephone consultation: +370 651 11191