Tankless Water Heater Closed Loop System

The advantages of a continuously active heat exchanger loop are twofold.

Tankless water heater closed loop system.

Water heated by the tankless heater flows directly through the floor tubing while a heat exchanger provides heat for the dhw supply. However doing so in a way that doesn t waste a lot of energy is a little trickier. These are for closed systems usually called hydronic systems and they are just for heating. A closed water heater system means that the hot water cannot expand beyond the valves and mix with the municipal water.

This is called a closed loop heating system with domestic water. The box on the floor lower right is an air handler that includes a copper heat exchange coil. They are either a tank or tankless style and can be gas or electric. Tankless water heater as a heat source with domestic hot water.

The valves that are usually found in the closed systems are the check valve pressure reducing valve mixing valve backflow preventer and other. Creating the loop is fairly easy. Timed operation is recommended over an aquastat with the timer programmed to recirculate in early morning and evening when demand for hot water is greatest. Whenever needed the storage tank draws heat from the heat exchanger and maintains a constant tank temperature.

A hot water loop uses a small pump to circulate hot water between a water heater and a distant bathroom or kitchen. A continuously operating pump is clearly wasteful. Above the air handler is a smaller box containing the cooling coil. This space heating system is a hydro air system using a rheem tankless water heater seen on the left.

The tankless water heater also provides domestic hot water. The water from the boiler to this heat exchanger flows 24 hours a day in a closed loop making the heat exchanger continuously active i e. These systems are typically connected to a source that s heats the water such as a boiler or a tankless water heater in which the heating. Closed loop radiant heating systems are the more preferred option for most plumbers but are also more expensive due to the need for a secondary heating unit to be installed for optimal heating purposes.

The author s radiant distribution system consists of a primary loop with a heat exchanger for domestic hot water and secondary loops for each heating zone. Insulate all hot water pipes to minimize standby energy loss. They can be used with radiators or radiant floor heating. Tips when installing a tankless recirculation system.

This is an example of how to set up a tankless water heater as a heat source and for your domestic hot water. This is only an example.