​Domestic Hot Water Recirculation Systems

Temperature Balance in Domestic Water Recirculation Systems

Why depend on flow balance when you are trying to achieve a temperature? Why run constant flow when a Bell & Gossett Temp Setter Balance Valve will modulate to maintain the temperature?

"Best Balancing: A B&G model TB Temp Setter Balance Valve

The B&G Temp Setter regulates the recirculation flow rate to maintain the design temperature at the valve. It is also available with manual or BMS controlled high temperature bypass for sterilization per ASHRAE Standard 188-2018.

Bell & Gossett recognizes concerns with having the thermal wax element in contact with the water. This design assures the integrity of the element by keeping it our of the water flow. Many competitive devices do not have this advantage.

Features/Highlights

• Saves Energy – reduces flow when satisfied
• Adjustable temperature range - 95°F to 150°F
• Reduces flow when the temperature is met
• The thermal wax is NOT in contact with the water
• Optional manual Legionella disinfecting bypass
• Optional 24 volt Automatic Legionella disinfecting bypass for BMS control

Which do I select?

• ½” with no disinfecting bypass model TS-1/2
• ¾” with no disinfecting bypass model TS-3/4
• ½” with manual disinfecting bypass model TSB-1/2
• ¾” with manual disinfecting bypass model TSB-3/4
• For BMS auto disinfecting add TSB actuator and adaptor

Automatic Balance in Domestic Water Recirculation Systems

One challenge with Domestic Hot Water Recirculation Systems is the setting of the flow balance valves. Our BETTER system would use the Griswold automatic flow balance valves. These valves will modulate to maintain the flow rate.

Better Balancing: A Griswold “K” Valve

The Griswold “K” style automatic flow control valve is pre-set at a specified flow rate The valve automatically adjusts to maintain the flow rate and needs no external manual balance. Any over head of the pump is taken up by the balance valve. This prevents too high a velocity in the copper pipe in an unbalanced system.

Features/Highlights

• Low lead design is available (specify the right model for plumbing)
• Automatic pre-set flow rates eliminate the need for manual balance saving contractor time
• Pressure ports allow the reading of the differential if needed.

Manual Balance in Domestic Water Recirculation Systems

Manual Balance with Constant Speed Pumps

The traditional domestic water recirculation system goes back in time a long way. At the end of each hot water plumbing supply, the engineer adds a manual combination balance and flow measurement valve. From there, a small return is piped to the water heater. The pumps are normally small factional horsepower constant speed pumps.​

Good Balancing: The Bell & Gossett Circuit Setter

The Bell & Gossett Circuit Setter manual balance valve has many distinct advantages in plumbing system recirculation systems.

Features/Highlights

• Low lead design meets most State and local requirements
• Memory stop feature
• Combination balance and flow measuring valve allows readout during balance
• The preset feature of the variable orifice device allows for simple setting using the Bell & Gossett circuit setter portion of the System Syzer program as the valve is installed saving the plumber time.

Capacity Ranges

"Good" Pumping: The Bell & Gossett Inline Potable Water Pump

Bell & Gossett provides a number of choices for potable water applications. The difference between them is capacity, starting power, cost, and energy saving potential.

B&G SSF, NBF and PLB pumps are ideal for Commercial and Institutional Systems with a recirculation line.

Features/Highlights

• SSF series: Low capacity, low wattage energy use, wet rotor
• NBF 25,36, 45: Low capacity, 3 speed helps balance, low wattage, wet rotor
• PLB: Medium capacity, high starting torque is good for hard water

"High-Rise" Balance in Domestic Water Recirculation Systems

High rise buildings require multiple “Pressure Zones” depending on the height and horizontal run of the plumbing system. The selection of balance valves, recirculation pumps, and system design can vary dramatically.

The R.L. Deppmann series "HRR" zone recirculation package will assure proper flow to all floors while provided the best use of pumping energy. This package is pre-assembled with all of the components required. Specifying this package saves the engineer design time while providing unit responsibility for the operation of the system.

Low Flow and Hot Water Complaints Solved with the HRR System. The Trouble with Traditional High Rise Designs.

Traditional domestic water recirculation systems in single pressure booster high rise design normally follows a simple design. One design, shown here, has a pump for each zone. This leads to multiple pumps with very low flow rates and high heads. 

If a single high head pump is used there will be a balance problem. Upper zone balance valves will be throttled so severely that they may plug or create a whistle noise.

The RLD series HRR package solves the two common issues with these systems.

Features/Highlights

• Each zone has its own low head pump
• Complete package reduces field labor
• Complete package reduces detailing and coordination in design
• Wall mounting in small spaces
• Multiple flow and temperature models available

"Residential and Small Commercial" Domestic Water Recirculation Systems

We have all experienced the frustration of turning on the shower and having to wait for the water to get hot. It doesn't have to be like that. A domestic hot water recirculation system keeps the water at the furthest fixture warm so you don’t have to wait. Smaller commercial and home systems may or may not have a dedicated return piping system.

R. L. Deppmann offers three solutions for these smaller systems:

• Undersink B&G ecocirc B23 5 ACT system – no recirculation line needed.
• Undersink B&G ecocirc wireless – no power outlet needed
• Traditional recirc line - B&G ecocirc