Modular purification air conditioning units with smaller air volume are shipped as assembled modules and installed on-site. This is similar to the installation of general modular air conditioning units, which are composed of different functional sections. For units with large air volume, components are sometimes shipped separately and assembled on-site.
The unit panels are made of composite boards, with polyurethane material commonly used as the core. The outer layer is made of color-coated steel plates, plastic-sprayed steel plates, etc., and the inner layer is made of color-coated steel plates or stainless steel plates. For biological clean rooms, especially in hospital clean operating departments, the inner side of the unit panels is mostly made of stainless steel, and stainless steel fans are used. The connections between each section of the unit are usually fastened with bolts, and sponge rubber boards are used to seal the seams. Installation is generally carried out by personnel sent by the manufacturer or guided by their technicians.
Before installation, the delivery list and detailed list from the manufacturer should be carefully checked, and with the supervision personnel, it should be confirmed whether all functional sections are complete, whether the direction of the pipe interfaces is correct; whether the number of rows, dimensions, and materials of the heating and cooling coils match the design drawings; whether the fan model, technical parameters, and connection with the motor conform to the design.
Special attention should be paid to whether the fins of the heat exchanger are stacked, whether the heat exchange tubes are damaged; check the quality certificates of fans and heat exchangers, and inspect whether the unit panels are damaged. After verifying all items, fill in the “Project Material/Component/Equipment Approval Form” for filing.
Below are the foundation requirements for the modular air conditioning unit:
The foundation should be made of reinforced concrete. The foundation’s length and width should each be 100mm longer than the unit’s outer dimensions.
The foundation height should be determined according to the water seal and drainage slope of the condensate drainage pipe. The foundation surface must be flat, and the diagonal horizontal error should not exceed 5mm. To protect the bottom panel of the unit from corrosion, it is advisable to place two suitable I-beams or channel steels (laid longitudinally) under the unit. Under the cooling coil, heating coil, and fan section, additional steel beams should be added as appropriate. Transverse steel beams should be set under the fan to increase strength. The construction errors of the foundation surface can also be eliminated by adjusting the steel beams. The I-beams or channel steels under the unit should be treated for anti-corrosion and rust prevention.
After all preparation work is completed, the area should be thoroughly cleaned. During installation, no other dusty work types should be cross-operating.
For modular air conditioning units shipped as parts, installation should in principle proceed sequentially from one end to the other. However, since the cooling coil, heating coil, fan, and their bases are relatively heavy, after the base plate of the corresponding section is installed, these devices should be hoisted first. Generally, the manufacturer has already assembled the fan and motor on the vibration damping base, so there is no need to disassemble them during installation unless the dimensions are too large to enter the door.
When disassembly is necessary for installation, the motor’s position should be adjusted before assembling the side panels. After these heavy components are in place, remove the hoisting equipment, install all base panels, level and align them, and seal all joints.
Three points need special attention:
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The power cable entry of the unit should be enclosed in a conduit and sealed tightly. The conduit should extend to the motor junction box.
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During installation, the fan’s vibration isolator should be protected. The rigid protection block should be removed only after the fan is in place, so that the isolator bears force evenly.
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The slope of the stainless steel condensate tray under the cooling coil should be properly adjusted to ensure smooth drainage without dead corners. The height of the water seal should be determined according to the design drawings.
At this point, installation can proceed in sequence from one end to the other. First install the side panels, then the top panels. During the installation process, the cooling coil, heating coil, and fan should be temporarily covered with plastic film to prevent dust from entering. When assembling the unit wall panels, dust on the panels and components should be wiped off at any time. Check whether the sealing materials are neatly arranged and undamaged, and replace them if necessary.
The bolts should be evenly tightened. After the unit is assembled and the maintenance door is in place, the interior of the modular air conditioning unit should be cleaned again. Remove the temporary protective films on the cooling coil and heater. Wear clean work clothes and shoes, install primary and medium efficiency filters, connect the power supply and maintenance safety lights.
After the air conditioning unit is fully assembled, leakage testing should be carried out with the supervision personnel. At a static pressure of 1000Pa, if the cleanroom cleanliness is lower than ISO5 (Class 100), the leakage rate should not exceed 2%; if the cleanliness is equal to or higher than ISO5 (Class 100), the leakage rate should not exceed 1% (For testing equipment, refer to the “Ventilation and Air Conditioning Engineering Construction Quality Acceptance Code” GB50243-2002). After passing the leakage test, fill in the air leakage inspection and acceptance form, sign and seal it for filing.
For modular purification air conditioning units shipped as complete components, the installation is relatively simple: just connect each section in order, level and align them, and seal the joints tightly.
The water inlet and outlet interfaces of the cooling and heating coils of the modular purification air conditioning unit are usually external threaded interfaces. During the piping process, the maximum pipe diameter that can be threaded by on-site threading tools often does not meet the pipe diameter requirements. Some units use lathes to machine the threads of the connecting pipe section and use pipe couplings for threaded connections. If the threads are machined with errors, leakage is likely to occur during pressure testing and is difficult to fix.
Therefore, many construction teams usually use flange connections for these large-diameter threaded interfaces, which are more convenient and reliable. This also avoids the increased installation length caused by the need for union fittings in threaded connections.
When welding flanges at the water pipe interface of the already installed modular air conditioning unit’s cooling and heating coil sections, special care should be taken to protect the unit wall panels. Usually, multiple layers of wetted asbestos cloth are attached and covered near the pipe interface wall panel, with a metal plate shielding the outside to prevent sparks from damaging the wall panels during welding.
