CONDITIONING PLANTS
SPLIT and COMPACT models
page 23
www.climma.it
5 SMOOTH RUNNING CHECK
Proceed as follows:
1.- Calculate the free area of the return grill in sq. m.. The free area is the actual size of the grill without the
external frame.
2.- Check velocity of air in different points of the grill.
3.- Calculate the average air speed through the grill in mt/min or in mt/sec according to the instrument.
4.- Use the following formula to obtain the total air quantity which is circulated by the unit:
Q = SxVx3600
Q = SxVx60
Where:
Q = Total air flow ( cm/h )
S = Grill surface ( free ) ( sq.m. )
V = Air speed mt/min or mt/sec
3600 = to be used with mt/sec speed
60 = to be used with mt/min speed
From these data it can be obtained:
S=
Q
Vx3600
--------------
S=
Q
Vx60
----------
V=
Q
Sx3600
--------------
V=
Q
Sx60
----------
The total air flow in cm./h should meet the value given in technical data. It is acceptable that the total air
flow is reduced of 15-20% but not more.
Also delivery grills air flow must be checked in order to balance the system when two or more delivery grills
are installed or to make a comparaison with the intake grill. When you need to air-condition two or more
cabins, it is necessary to calculate the air quantity to introduce. This value can be calculated only knowing
the warmth charge in each cabin.
To determine the air quantity needed by each cabin, use the following procedure:
1- Divide the total air flow by the total surface conditioned ( rate treated air/ treated volume )
2- Multiply the number obtained for the volume of each cabin ( treated air quantity to introduce )
EXAMPLE:
Volume aria trattata in mc/h VT
Volume condizionato dinette mc VC
Volume condizionato cabina mc VC
Totale mc. VC
Rapporto VT/VC
700
25
15
40
17,5
Mc aria dinette = 25x17,5
Mc aria cabina = 15x17,5
Totale mc/h
438
263
700
Total treated air in Cu.M./h VT
Volume of dinette in Cu.M.
Volume of cabin in Cu.M
Total volume VC in Cu.M.
Rate VT/VC
Dinette treated air in Cu.M./h= 25x17,5
Cabin treated air in Cu.M./h= 15x17,5
Total of treated air in Cu.M./h
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