Technical stickers: Central air conditioning load calculation and equipment selection

Mondo Home Updated on 2024-02-01

schematic diagrams, which do not correspond to any specific information in the text).

1. Calculation of air-conditioning load of various buildings1. What is the air conditioning load?

1) In order to maintain a certain temperature in the room, the cooling capacity that needs to be sent to the room is called the cooling load.

2) The heat that needs to be sent to the room in order to compensate for the heat lost in the room is called the heat load.

3) The amount of moisture that needs to be removed or increased by the room in order to maintain the relative humidity in the room is called the humidity load.

2. What are the factors that affect the size of the load?

1) Climatic conditions.

2) Usable area.

3) The number and orientation of windows.

4) The orientation of the exterior wall.

5) Maintain the thermal insulation effect of the structure.

6) Room use.

7) The number of people in the room.

8) Heat dissipation with electrical appliances.

3. Budget estimates for different construction loads

Under normal circumstances, the load of office buildings, office rooms and guest rooms can be calculated at about 90,100 kcal per square meter, conference rooms, theaters and studios at about 160,200 kcal per square meter, and hotels, baths and restaurants at 160,260 kcal per square meter.

Note: l. The above indicators are the cooling load indicators of the total construction area: when the total construction area of the construction area is less than 5,000 square meters, the upper limit is taken; If it is greater than l0000 square meters, the lower limit value will be taken.

2. The cooling load determined according to the above indicators is the capacity of the refrigerator, and there is no need to add a coefficient.

3. Due to the large regional differences, the above indicators are subject to Beijing. The southern region can be taken according to the upper limit.

2. Comparison of advantages and disadvantages of air conditioning solutions1. Single cooling system

2. Combination of cold and heat (heat pump system, gas boiler refrigeration).

3. Duct system, water system, heating duct system

3. Equipment selection

1. How to choose the refrigeration host?

The air-conditioning cooling load is calculated according to the air-conditioning area and room function of the building.

Statistics on the total load of air conditioning in the building.

Most buildings need to consider the simultaneous occupancy rate of rooms, and the simultaneous occupancy rate of general buildings is 70 80%, and special circumstances need to be determined according to the function and use of the building.

The chiller cooling load is the product of the total air conditioning load of the building and the simultaneous usage rate. Depending on the calculated chiller cooling load, the main chiller unit can be selected.

The number of refrigeration hosts can be determined according to the situation of the building owner and the equipment room of the building.

The host form can be determined according to the actual situation of the owner or according to the comparison of various schemes according to the project situation, and the most suitable host form for the project can be selected.

2. How to select the fan coil unit?

A: There are two main parameters of the fan coil unit: cooling (heat) volume and air supply volume, so there are two methods to choose:

1) According to the room circulation air volume selection: the product of the room area, floor height (after the ceiling) and the number of room ventilation is the circulation air volume of the room. The model of the fan coil unit can be determined by using the circulating air volume corresponding to the high and medium speed air volume of the fan coil unit.

2) Select the cooling load required by the room: according to the unit area load and the room area, the cooling load value required by the room can be obtained, and the fan coil unit model can be determined by using the cooling capacity of the fan coil unit corresponding to the room cooling load.

3. What is the installation form of the fan coil unit?

After determining the model, it is also necessary to determine the installation method of the fan coil unit (surface installation or concealed installation), the return air mode (bottom return to the bottom, the side to the bottom return, etc.) and the connection position of the water pipe (left or right) according to the building structure and the actual needs of Party A.

4. How to divide the left and right forms of air conditioning equipment?

Fan coil unit - facing the air supply outlet, the inlet and outlet of the fan coil unit is right on the right side, and vice versa.

Ceiling air conditioner - facing the return air outlet, the inlet and outlet of the unit are right on the right side, and the reverse is left.

Cabinet air conditioner - facing the return air outlet, the inlet and outlet of the unit are right-handed, and the opposite is left-handed.

Combined air conditioner - facing the return air outlet of the combined air conditioner, the water inlet and outlet are right on the right side, and vice versa.

5. Fan coil unit model estimation:

Answer: For general residential and office buildings, if the room area is less than 10m2, you can choose FP-35, about 15m2 choose FP-51, about 20m2 choose FP-68, about 25m2 choose FP-85, about 30m2 choose FP-102, about 40m2 choose FP-136, about 50m2 choose FP-170, and about 60m2 choose FP-204. When the room area is large, multiple fan coil units should be considered, and when the unit area load of the room is large, the fan coil unit with large air volume and cooling capacity can be considered when the noise requirements are not high.

6. Selection of air conditioning unit:

The air handling unit is mainly used to treat indoor air and supply fresh air, and generally has two working conditions: return air condition and fresh air condition.

The selection of an air handling unit is generally determined by three main parameters: air volume, number of surface cooler pipes, and external residual pressure.

The type of AHU unit is determined based on the amount of air required by the system, and then the number of pipes is determined according to the cooling capacity that needs to be provided. The residual pressure is determined according to the residual pressure requirements required by the system.

Air handling units generally have two types: ceiling type and floor type. There are two types of floor-standing types: vertical and horizontal. In addition, the air return mode of the unit is also different. Xu makes the final determination according to the building situation and the requirements of the building owner.

Note:The cooling (heat) capacity of the air conditioner is smaller than that of the fresh air condition.

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