“Dual Temperature Systems and Mixing Valves” “Performance Conditions of a Mixing Valve” Last week the R L Deppmann Monday Morning Minute article examined the addition of a mixing valve. Today we will examine the re-circulation system with dual temperature requirements and answer questions about the term “Performance Conditions” mentioned in the Lawler literature.
Why RO Is the Backbone of Modern Building Water: From Humidifiers to ST108 Compliance
Across commercial, educational, and healthcare environments, Reverse Osmosis (RO) is becoming one of the most effective ways to control the water quality variables that lead …
Domestic Water Recirculation Systems Part 7: Mixing Valves
“Addition of a Mixing Valve” During the last 6 weeks, the R. L. Deppmann Monday Morning Minutes concentrated on re-circulation systems where the supply temperature to the system was the same as the outlet temperature of the water heater. Today we will examine the addition of a Lawler master mixing valve in the system.
Domestic Water Recirculation Systems Part 6: High Rise Considerations
High Rise Considerations The last article, part 5, showed an example of a high rise system with pressure reducing valves (PRVS) and the importance of the correct setting of the balance valves. The example we used showed balance valves with as much as 18 PSIG across them at a low flow. When a design starts to incorporate
R.L. Deppmann Expands Danfoss Territory to Include West Michigan
We’re proud to announce that R.L. Deppmann has expanded its territory to include West Michigan and is now the official manufacturer’s representative for Danfoss across …
Domestic Water Recirculation Systems Part 5: Settings
High Rise Considerations The last article, Part 4, showed an example of a high-rise system with pressure reducing valves (PRV’s) and their effect on the …
Domestic Water Recirculation Systems Part 4: High Rise Considerations
The last three articles outlined pump selection in domestic water recirculation systems. In general, these systems have low flow and low head pumps. What happens in a high rise with pressure reducing valves (PRV) in the hot water supply? The pressure reducing valve introduces a fixed pressure drop which must be added to the calculations.
Domestic Water Recirculation Systems Part 3: Pressure Drop
The purpose of the domestic water recirculation system is to delivery hot water near a fixture during times when there is no draw. If someone is using hot water in the next room or apartment or process; the hot water is near enough to your fixture so the hot water is delivered in seconds, not minutes.
Plumbing Topic: Domestic Water Recirculation Systems Part 2
Let’s assume the domestic hot water supply is a total length of 1000 ft. That is the entire pipe on all of the floors. Let’s also assume an average of 15 BTU/hr/ft of loss through the supply pipe insulation. Now let’s assume the recirc piping is 300 ft total at an average of 10 BTU/hr/ft of loss. What flow rate is required for a 10 degree ΔT? What flow rate is required for a 5 ΔT?
Case Study: Stabilizing Cooling Tower & Closed Loop Performance at CoCoWalk
Problem Identified CoCoWalk, a large multitenant lifestyle center in Florida, was faced with the following water quality challenges across their cooling tower and closed-loop …










