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?
The R. L. Deppmann Monday Morning Minutes series will focus on the plumbing portion of the new construction and building facility business for the next few months. The topics will be domestic water recirculating systems, pressure booster systems, volume and instantaneous water heaters, and mixing valves. I’ve had 6 job site visits in the last 2 months to help engineers, service contractors, and facility managers solve problems with domestic water recirculating systems. It seems this is a good place to start.
Often engineers will voice concern about failure of an underground pump and the possibility of water damage. The key to reducing any damage is the …
Over the last few weeks the Monday Morning Minutes (MMM) posts have reviewed the use of tankless water heaters vs. traditional storage type water heater …
The Monday Morning Minutes of the last two weeks introduced some differences between plate heat exchangers. Two of the products featured were the double wall plate & frame and double wall brazed plate heat exchangers. We have received many calls regarding these models and Michigan and Ohio plumbing codes. The plumbing code is very specific in its
Centrifugal pumps are the “heart” of hydronic heating, cooling, and plumbing systems. Over the next few weeks, the R. L. Deppmann Monday Morning Minutes features some basic and advanced pumping topics. Let’s start with a quick review of the information contained on the pump curve. For our example, we will use an ITT Bell and Gossett model 1510 end suction base mounted centrifugal pump model 5E with a nominal speed of 1750 RPM. The horizontal axis is flow rate in GPM or gallons per minute of water. [Read more…]