We recently had an inquiry from an engineer who was concerned about pump operation compared with the submitted pump curve. It appeared from the balance …
The Department of Energy (DOE) Pump Standards – Now is the Time to Choose
The Department of Energy (DOE) pump standards goes into effect on January 27, 2020. This affects projects you are sending out to bid right now! …
Piping Pressure Drop Correction Factors when using Glycol in Hydronic HVAC Systems
The last couple of R. L. Deppmann Monday Morning Minutes introduced the BTUH corrections required when using glycol in hydronic heating and cooling systems. …
BTUH Correction Factors when using Ethylene Glycol in Hydronic HVAC Systems
In the last R. L. Deppmann Monday Morning Minute, I provided the BTUH correction factors for propylene glycol. We don’t want to play favorites so …
Propylene Glycol BTUH Correction Factors in Hydronic HVAC Systems
We are all familiar with the BTUH formula (BTUH = GPM x ΔT x 500) used to calculate the gallons per minute (GPM) water flow …
Condensing Boilers and Air Handing Unit (AHU): Hydronic Hot Water Coil Return Temperature
Correction to my 8-26-19 blog. In the rush to get on vacation I messed up on my math. This is corrected. Thank you to Tom …
Domestic Water Heaters: Plate Heat Exchangers and Dual Return Condensing Boilers
Gas-fired storage type domestic water heaters are the norm in commercial and institutional buildings. Walk into any mechanical room of a larger complex and you …
Hydronic Primary/Secondary Heating-Cooling (Chiller) Changeover Systems
Once in a while, we still see the two pipe heating or cooling system with a manual or automatic changeover process that the owner uses …
Condensing Boilers and Air Handling Units (AHU): Hydronic Hot Water Coil Return Temperature
Hydronic system hot water coils in air handling units often have secondary pumps for freeze protection. The hot water coils usually have design temperatures that …
Hydronic Radiant System Secondary Temperature Control Using “The Law of the Tee”
Primary-Secondary hydronic piping is a common piping scheme in today’s hydronic heating and cooling systems. This article will show you how to use this common …