1. >1.3kW heat dissipation capacity*
2. Suitable for fresh water or glycol/water systems.
3. Anodized aluminiun fins and outer casing for excellent corrosion resistance
4. Silver brazed copper piping with 1/2" M BSP inlet and outlet.
5. Easy mounting on exterior wall or in roof space.
6. Able to be connected in series for greater heat dissipation capacity.
7. Minimal pressure drop.
8. May be used as a simple hydronic space heating panel.
9. Neat, attractive design.
* Based on 80oC / 176oF water temp, 40oC / 104oF ambient, no forced air flow.

The HD is installed on the return line from the solar collector(s). When the temperature in the storage tank exceeds the pre-set limit (~80oC / 176oF), the controller switches a solenoid which directs the solar return flow through the HD before returning it back into the standard flow line. Alternatively a thermostatic mixing valve/tempering valve set to a suitable temperature can be used, providing mechanic, automatic regulation of flow through the heat dissipator.

As the hot water passes through the HD, heat is dissipated via the aluminium fins to surrounding air, the vertical fin arrangement promoting a passsive air current.

One HD-25 unit can dissipate 100% of the heat produced by an AP-30 collector in full sun, during very high ambient temperatures.

The copper pipe to and from the collector should be heavily insulated, as should the lengths of pipe to and from the HD. The solenoid valve prevents flow of collector return water through the HD during normal temperature operation, thus preventing unnecessary heat loss.