The prime purpose of the Nordic pool conditioner unit is to maintain proper humidity levels in the pool room as well as providing heat to the pool and the pool room. The Nordic unit accomplishes these tasks in the following manner:
When the pool aquastat is satisfied a relay closes activating the 3-way valve which diverts any further heat generated by the operation of the machine, back to the room. Thus if the room humidistat calls for dehumidification and the pool aquastat is satisfied there will be a net increase in pool air temperature since the sensible & latent heat removed from the room through the dehumidification process will be added to the compressor and blower watts and returned to the room in the form of sensible heat.
All the losses in the pool area through evaporation can be recovered. During this process there is additional heat, equal to the amount of watts that the compressor & blower in the system consume, which can be added to either the pool water or pool air as required. Therefore the only losses which will have to be made up electrically by the plenum heater are typically those from the pool room shell which exceed the input watts (converted to heating Btu's) of the conditioner.
On initial startup of the pool area, the pool aquastat will call for heat. This signal will activate the conditioning unit in mode (1) which will cool and dehumidify the air and deposit the heat in the pool water. During this operation the pool room temperature will fall below the set point of the room thermostat, activating the plenum heater which will supply make-up heat to the pool room. Since the plenum heater has greater heating capacity than the cooling capacity of the conditioner unit there will be a net gain of heat in the room. When the room reaches set point temperature the plenum heater will cycle off until again called to replenish the room heat. This cycling will continue until the pool comes up to temperature.
Indoor Pool Conditioner Units
Method of Operation
This unit can perform (3) functions in an enclosed pool area.
Dehumidify pool area - returning all latent heat plus compressor & blower motor heat to the pool or to the air as the situation requires.
Heat the pool water.
Heat the pool air.
The pool area and the pool water have a Btu loss on a continuous basis during winter. Most of the heat loss from the pool water is through evaporation, assuming the walls of the pool are insulated. The Nordic "PC" will recover all the latent heat lost through evaporation and return it to the water via it's internal water cooled condenser and the pool's circulation system. There will always be additional heat available to heat the pool equal to the amount of electricity consumed by the compressor and blower of the conditioning unit.
Equation:
Heat available from the operation of the PC unit = Total watts of power used to operate the heat pump.
Total heat added to the room and water will be from 3500 watts to 6500 watts depending on the unit size (3-5.75 HP). This power consumed in watts converted to Btu's is from 12,000 to 22,000 Btu's. If less than this amount of heat is needed to maintain the pool temperature, then the remainder is diverted back to the pool air. If the combination of pool loss + pool room loss through walls and glass etc. are less than the 12 to 22,000 Btu produced by the "PC" unit while it is dehumidifing then no additional heat will be required by either the pool water or the pool room air.
An electric plenum heater can be used in conjunction with the "PC" unit to make up a complete package which can bring a cold pool up to temperature. Once the pool is up to temperature the plenum heater will not have to operate unless there are large heat losses in the pool room during winter operation.
