Domestic Hot Water Recirculation Pump Sizing

The alpha 15 55 hwr d is a recirculation system that delivers hot water in homes at the push of a button and can save thousands of gallons of water each year.

Domestic hot water recirculation pump sizing. From a cost and environmental point of view far less water is wasted each time a hot water faucet is opened saving an average of 12 000 gallons of water annually for a typical four person. Designing the domestic hot water recirculating system. 11 head ft. Using a hot water recirculation pump eliminates instantly this expensive and annoying wait.

Fitting a pump to manage this amount of the load should give you 90 95 percent of the hot water needs for your home. Domestic hot water recirculation steps. If the system has. Compare that to gpm times the number of balance valves and choose the larger value.

With a hot water recirculation system you can guarantee your customers the luxury of hot water in an instant becoming an increasingly scarce resource we waste millions of m3 every year as we wait for hot water when we turn on the tap. Part 1 find the pump gpm determine the heat loss of the total supply pipe using tables or rules of thumb. The armstrong astro 2 hot water re circulation system automatically circulates water through domestic water pipes. Ecm high efficiency hot water recirculation system gpm.

All circulator pumps are typically sized based on the heat load and head loss pressure drop for a given zone. If the pump is undersized recirculated hot water will not stay warm enough. Calculate the gpm required using a 10 f δt or other value as determined by the engineer. Sized correctly a recirculation pump will be as small as possible to keep the recirculated water at the design temperature.

44 sizes in. In fact we see the exact same model recirculation pump used in application after application without incident as this one pump is typically able to meet the minor head and flow requirements of most recirculation systems. Circulating pumps should be sized to meet around 60 percent of the heating load which is the calculation you have performed including water needs leakage and pressure. The aspe plumbing engineering design handbook available to aspe members has a precise way of sizing the circulating pump based on a 20 degree temperature differential from the water heater out to the farthest fixture and back to the circulator near the water heater.

Designing a domestic hot water recirculation system is not typically difficult. 1 union 1 2 3 4 fittings sold separately. Knowing the heat load in btu s for a given zone allows to calculate the required circulator pump s flow rate in gallons per minute gpm.