This week, the R. L. Deppmann Monday Morning Minutes will explain how to show multiple speeds on a pump curve and how to determine what …
Hydronic Pump Balance Using the Variable Speed Drive (VFD) with No Balance Valve on Pump
When there is no hydronic pump discharge balance valve, the variable frequency drive (VFD) is an important part of the balance procedure. How does the …
Hydronic Pump Balance using the Variable Speed Drive (VFD) with Assistance from a Triple Duty Valve
Most centrifugal pumps in heating and cooling systems have some oversizing in the head calculation. Once the HVAC hydronic system is proportionally balanced per ASHRAE …
Variable Speed Hydronic Pump Selection – Should I Specify the Largest Impeller?
We recently received an inquiry from an engineering firm deciding whether to change their pump schedule. They currently select the pumps at design capacity and …
The Importance of Turndown Ratio in Condensing Boilers & Water Heaters
Turndown was defined in Part 1 of this short series. In general, hydronic water tube boilers have a lower possible turndown ratio than fire tube …
Commercial Gas Fired Water Heaters – Cost of Ownership
When you’re researching water heaters, you first ensure that the product meets your needs technically (flow, heat input or source, space requirements, and recovery …
Commercial Gas Fired Water Heaters – The Battle of Efficiency Between Tankless & Storage
Tankless, sometimes called instantaneous, and storage water heaters have been utilized in commercial and institutional buildings for a long time. The overwhelming majority of these …
Commercial Gas Fired Water Heaters – Materials of Construction
Gas fired commercial water heaters come in a variety of materials of construction. Most available offerings fall into three categories. What are these materials and …
Commercial Gas Fired Water Heater Types
In our world, a certain style of water heater may be referred to with many different names. Over the next few weeks, the R. L. …
Sizing Pressure Relief Valves for Closed Chilled Water Systems
Pressure relief valve sizing for heating systems is well documented by ASHRAE, boiler codes, and product manufacturers such as Bell & Gossett. Relief valve sizing …