Design And Selection; Selection Principle; Selection Steps; Example For Selection - Gree FP-22LM/D-K Service Manual

DESIGN AND SELECTION

1 Selection principle

1.1 Selection steps

(1) If the external static pressure is 0Pa, the unit cannot be connected with ducts.
(2) Select the unit type based on the air flow, cooling capacity and heating capacity.
(3) Select the unit model based on the indoor cooling/heating load, inlet air DB/WB temperature,
entering water temperature and related data sheets. The cooling/heating capacity of the selected
unit should be or larger than the indoor cold/heat load.
(4) Take consideration of sound level.
According to the allowable sound level of the corresponding building (as shown in the table below for
reference), check if the selected unit can meet the sound requirement.
Type of buildings
Recording studio, broadcast studio, dubbing room
Concert hall, theatre, television studio
Cinema, lecture theatre, meeting room
Office room, design office, reading room
Restaurant, banquet hall, gym, hotel
Waiting room, shopping center
Cleaning room, office room with mechanical appliance
It is cited from Practical Design Manual of Heating Air Conditioning. If undesirable; reselect the unit
with lower sound level.

1.2 Example for selection

For a room of a hotel, the cooling load is 3090W, the inlet air dry bulb temperature is 27°C, the inlet
air wet bulb temperature is 19°C, the air flow is 600m
leaving water temperature is 12°C; the heating load is 3800W, the inlet air dry bulb temperature is 20°C,
the inlet air wet bulb temperature is no more than 15°C, the entering water temperature is 45°C and the
leaving water temperature is 40°C. Based on these conditions, select a proper FCU.
Step 1: Select the unit type based on the air flow, cooling capacity and heating capacity.
(1) Select the unit model based on the maximum cooling load.
(2) Select the cooling capacity at the high air flow to meet the average cooling load.
(3) In light of working conditions, the cooling capacity selected from the data sheet is equal to or larger
than the cooling load.
(4) When the cooling capacity is selected based on the medium or low speed air flow, then at specific
or load peak, use the high-speed for meeting the load demand.
(5) For the selected FP-68 in light of loads, its data sheet shows that the cooling capacity is 3200W,
heating capacity is 3800W and the air flow is 680m
(6) When the entering water temperature is 60°C, the heating capacity is 7000W, which meets the load
demand.
Design and Selection
Allowed sound level
3
/h, the entering water temperature is 7°C and the
3
/h.
19
A-weighted sound level dB(A)
20~25
25~30
30~35
35~40
40~50
45~55
55~65