SELECTION PROCEDURE
1. Model Selection (With actual examples)
First step, to select the approximate model:
Based on the cooling load and the cooling capacity listed in the capacity table, select the applicable model.
Second step, to select the model:
To select the model, the following conditions must be known:
(1)Total cooling load or sensible cooling load
(2)Indoor conditioned temperature (WB*1, DB)
(3)Designed outdoor temperature (DB)*2
(4)Designed air flow
(5)Designed external static pressure (= Wind pressure loss of air duct)*3
Notes:
*1. The correct WB is required since it has a serious effect on the capacity.
*2. The cooling capacity decreases as the outdoor temperature increases. Therefore, the estimated highest temperature during an air conditioning time frame is the "designed outdoor temperature". However, it is recommended that the abnormal outdoor temperature which may occur once or twice a year be excluded from the calculation to avoid selection of an excessively large capacity model.
*3. The wind pressure loss of an air duct should be calculated correctly. If a value having an excessive allowance is used, an excessively large model will be selected. Moreover, an excessively high air flow will be induced during actual operation causing the generation of high operating sounds and
(Step-1) Confirmation of operation range
Confirm that the conditions given above for the model to be selected are within the
operation range listed on Page 36.
Based on the designed air flow and external static pressure, obtain the actual air flow, actual external static pressure, and fan motor power input from the fan performance table for the model selected. For an explanation of how to use the fan performance table, see the following examples.
Example: PE-8MYC, 50Hz
Example 1. (To operate with values near to the designed air flow and external static pressure.)
Condition : Designed air flow 70CMM
Designed external static pressure 60Pa
Calculation : The designed point is A. Therefore, duct resistance line passing A is
dotted line. |
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| 450 |
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Therefore, actual point is B for Δconnection |
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Actual air flow = 77CMM |
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Actual external static pressure = 70Pa |
| 350 |
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Notes: Duct resustance line is secondary curve. |
| 300 |
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| B |
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pressure |
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| 250 |
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| 60Pa |
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| 200 |
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| Total |
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| 150 |
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| 100 |
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| 50 | 55 | 60 |
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Fan speed
(rpm)
1400
1300
1200
1100
1000
900
800
- 14 - | Air flow (CMM) |
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