R. L. Deppmann News and Information

Parallel Pumping: 2-Position Control Valves on Multiple Cooling Towers (Part 5)

Over the last few weeks the Monday Morning Minutes posts have looked at pumping issues with multiple condensers and pumps. One of our most-received questions

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Parallel pumping sketch - ft. img

Parallel Pumping with Unequal Condensers (Part 4)

Over the last few weeks our Monday Morning Minutes posts have looked at pumping issues with parallel, equal-sized condensers and pumps. This week we will look

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Graphic 1

Parallel Pumping in Condenser Applications: Automatic Differential Pressure Control (Part 3)

Chilled water condensers are normally operated as constant-flow devices and the pumps serving them are constant-speed. Why would you ever use a variable-speed drive for

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LPD Y strainer

Selecting the Proper Glycol Concentration for Closed-Loop HVAC Systems

There are two basic types of glycol protection available for your closed-loop HVAC system: “burst protection” and “freeze protection.” Burst protection is sufficient if the

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Parallel Pumps in Condenser Applications: Limiting the Flow Rate (Part 2)

In part 1 of this series we offered an example condenser water pumping system. The design of this example is 800 GPM per condenser for

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Griswold wafer

Parallel Pumping in Condenser Applications (Part 1)

Applying a single constant-speed pump for each condenser in a chilled water application is a normal design for the HVAC engineer. The chiller manufacturers suggest

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parallel curve - featured

Bell & Gossett Part Load Efficiency Value (Part 5): BTUH Load Output vs. Percent of Flow Tolerance

The last four segments of the R. L. Deppmann Monday Morning Minutes introduced the valuable PLEV tool from Bell and Gossett. The part load efficiency

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How to Use the Part Load Efficiency Value

Condensate Traps on Dri-Steem Dispersion Tubes

Some installations of Dri-Steem dispersion tubes require a condensate trap or P-trap. Condensate traps help remove as much of the condensate from the steam as possible

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condensate traps on Dri-Steem dispersion tubes

Bell & Gossett Part Load Efficiency Value Part 4: End-of-Curve Selections

When looking at Bell and Gossett pump selections, we often find higher part load efficiency (PLEV) pump choices are to the right of the BEP, or best

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control curve of 30% of design head and variable speed

Bell & Gossett Part Load Efficiency Value Part 3: HVAC Pump Selection

In the last two Monday Morning Minutes, we introduced the PLEV, or Part Load Efficiency Value, from Bell and Gossett. When we use part load

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How to Use the Part Load Efficiency Value
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