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 …
Open Cooling Tower Systems – An External Water Treatment Example
External water treatment in cooling tower systems will save labor and operational costs. It also saves the planet by reducing your clients’ dependance on chemicals …