Flow Direction

The flow through the tube circuit can be in either direction.  The flow from the pool or spa can enter the tank from either direction as well, unless a thermostat sensor is used in the thermal bulb well to sense the temperature of the water entering the heat exchanger;  in that case, the water must enter the tank on the same end as the thermal bulb well.

Plumbing

Chlorinators or brominators must always be installed downstream of  the heat exchanger so that concentrated chemicals cannot flow into the heat exchanger when the pump/filter is not operating.  For further protection, install the chlorinator or brominator slightly lower than the heat exchanger.

Install a check valve in the coil circuit to prevent heat exchange from occuring  when the circulation pump is not running. Do not operate the heat exchanger when either the coil circuit or shell circuit is empty.  To avoid damage to the circulating pump, the coil circuit must be purged of air before putting the system into operation.

Multiple Units

Install multiple units in parallel, not in series.  Parallel installation assures minimum friction loss and maximum heat transfer.

Some solar applications require a higher exit temperature (tank circuit) than commonly used for pools and spas.  In this case, install the heat exchangers in series.  The flow through the tube circuit should be in the opposite direction of that in the tank circuit (cross-counterflow). 

Dielectric Unions

Recommended to avoid corrosion damage (electrolysis) when metals other than stainless steel are used in the installation, to isolate them from the heat exchanger. No metal other than stainless steel should be connected directly to the heat exchanger. Non-corrosive Dielectric Unions are available from Quality Pool Manufacturing Company.


Mounting Brackets

Use only stainless steel or plastic mounting brackets to mount the heat exchanger, to avoid external corrosion of the tank.  Optional stainless steel brackets are available from Quality Pool Manufacturing Company. 

Insulation

The heat exchanger and pipes should be insulated when installed in areas where temperatures fall below 45°F or the heat source water is above 160°F.  Insulating the pipes will always improve efficiency and is recommended.

pH

The pH must be maintained between 7.2 and 8.0. 
This is very important.  Failure to meet these conditions will result in tank corrosion.  Corrosion will also occur if water containing iron drips onto or comes into contact with the heat exchanger.

Oxidizers

Storing chlorine or bromine in the same room with the heat exchanger will corrode the exterior of the stainless steel tank.