Balancing of a Water and Air System (PDF
Balancing of a Water and Air System (PDF
Balancing of a Water and Air System (PDF
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SF = specific gravity <strong>of</strong> fluid<br />
If pressure drop is determined in feet <strong>of</strong> water, Equation (2) can<br />
be shown as {CV = 1.5 X Q √ (SF / ∆H)} (3)<br />
HYDRONIC BALANCING METHODS<br />
Various techniques are used to balance hydronic systems. Balance by temperature<br />
difference <strong>and</strong> water balance by proportional method is the most common.<br />
Preparation<br />
Minimally, preparation before balancing should include collecting the following:<br />
1. Pump submittal data; pump curves, motor data, etc<br />
2. Starter sizes <strong>and</strong> overloads protection information<br />
3. Control valve Cv ratings <strong>and</strong> temperature control diagrams<br />
4. Chiller, boiler, <strong>and</strong> heat exchanger information; flow head loss<br />
5. Terminal unit information; flow head data<br />
6. Pressure relief <strong>and</strong> reducing valve setting<br />
7. Flow meter calibration curves<br />
8. Other pertinent data such as readout conversion charts<br />
<strong>System</strong> Preparation for Static <strong>System</strong><br />
1. Examine piping system: Identify main pipes, risers, branches <strong>and</strong> terminals on as-built<br />
drawings. Check that flows for all balancing devices are indicated on drawings before<br />
beginning work. Check that design flows for each riser equal the sum <strong>of</strong> the design flows<br />
through the terminals.<br />
2. Examine reducing valve<br />
3. Examine pressure relief valves<br />
4. Examine expansion tank<br />
5. For pumps, confirm<br />
Location <strong>and</strong> size<br />
Vented volute<br />
Alignment<br />
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