Checking Supply Air CFM
To check the supply air CFM after the initial balancing has been completed:
1.Remove the two ¼ inch dot plugs in the duct panel.
a dry coil, the compressors should be deactivated while the test is being run.
4.Knowing the pressure drop across a dry coil, the actual CFM through the unit can be determined from the curve in Coil Delta P vs. Supply Air CFM figure.
2.Insert at least 8 inches of ¼ inch tubing into each of these |
| WARNING! Failure to properly adjust the total system air quan- | ||||||||||||||||||||
holes for sufficient penetration into the airflow on both sides of |
| tity can result in extensive system damage. |
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| 9 |
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the indoor coil. |
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| After readings have been obtained, remove | the tubes and rein- | |||||||||||||
3.Using an inclined manometer, | determine the pressure | drop |
| stall the two ¼ inch plugs removed in Step | 1. |
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| 7 |
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| the moisture on an | evapo- |
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| D1NA036 |
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across the dry evaporator coil. Since |
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rator coil may vary greatly, measuring | the pressure drop | across |
| NOTE: | ||||||||||||||||||
a wet coil under field conditionsD1NA018would be inaccurate. To | ensureD1NA024Coil | Deltame surementsPvsD1NA042Airflowto ensure a dry |
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CoilDeltaP | 4 |
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| D1NA08 |
| 36)3 | |
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| 2 |
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| Linear(D1NA018) | |||
| 3 |
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| 10 |
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| 600 | 800 | 1000 | 1200 | 1400 | 1600 | 1800 | 2000 | 2200 |
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ID | 400 |
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| Airflow(CFM) |
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Unitary Products Group | 7 |