Heating with a Domestic Hot Water System

Domestic hot water systems can be employed as a heat source for hydronic systems in some situations. Hot water is piped directly from the water heater or through a heat exchanger to the heat emitters of the hydronic system. In Wisconsin, all water heaters used for space heating must be tested and rated for such use.

We design and install small-scale heating and domestic hot water systems using conventional water heaters. Recently, we installed such a system for a small laundry facility. By combining the radiant floor heating and domestic hot water needed for the facility into one system, the customer saved a considerable amount of money compared with using two separate systems for heating and hot water.

Tankless Water Heaters

Tankless water heaters heat water continuously as it flows through the unit. They are more efficient than conventional, tank-type water heaters because they only heat water when the hot water is being used in the home. Conventional systems, maintain the temperature of the tank at all times and depend on insulation around the tank to prevent excessive heat loss. Tankless units can produce between 2-5 gallons of hot water per minute and are suitable for whole-house applications. Another advantage of tankless units is that they weigh less and take up less space than conventional water heaters.

Tankless water heaters are also an excellent backup system for solar domestic hot water systems. They can boost the temperature of solar-heated water during extended cloudy periods but use no energy when not needed. Tankless water heaters are not suitable for hydronic heating systems, and should not be used for space heating. They are designed for domestic hot water use only.

For more information on tankless water heater products, please visit our water heater products page.