How to judge whether the retained box is suitable before rebuilding the old air-conditioning box?

Whether the old air conditioning box can be retained should first check the structure, corrosion, sealing, insulation, cleaning and remaining space, and then confirm whether it can support the air volume and pressure after modification. Just because the appearance is acceptable does not mean that the frame and internal materials are suitable for continued use, nor does it mean that modification is easy just because the box is large.

Collect evidence from two lines: structure and usage conditions

Record equipment age, maintenance and leakage history, and inspect panels, frames, seams, door frames and bases. Damp insulation, chronic water accumulation or corrosion may be hiding behind the surface and require proper on-site inspection. When planning to add filters, fans or coils, the weight, support, and original structural endurance conditions must also be checked.

Condition evidence includes corrosion, deformation, leakage, insulation and cleaning conditions; functional evidence includes existing cross-sections, pressure conditions and maintenance access; modification constraints include additional weight, openings, supports and on-site construction conditions. All three lines must be recorded and cannot be judged based on appearance photos alone. How to choose between rebuilding the old cabinet and replacing the whole machine, please refer toHow to choose between complete replacement of air conditioning box and partial component update?。

Corrosion and insulation conditions often determine retention value

The degree of corrosion of the panel and frame, whether there are traces of water seepage at the joints, and whether the insulation layer is damp, directly affect whether the box can continue to be used. Surface rust can be treated, but structural thinning, punctures, or extensive insulation failure may cost nearly as much to repair as a replacement. Long-term water leakage may also cause the base and supports to weaken and require separate inspection.

Moisture in insulation not only affects energy consumption, but may also cause condensation on the outer surface and internal corrosion. During inspection, the access door should be opened to observe the inner surface, seams and bottom. If necessary, the panel should be partially disassembled to confirm the insulation status. For ideas on how to deal with rust on old frames, please refer toCan the old chemical filter still be used if its frame is rusty?。

Sealing and maintenance conditions affect the feasibility of transformation

If the original access door, door frame seals and panel joints have been deformed or the seals have failed, it may be difficult to meet the air tightness requirements after modification. After adding a new filter section or coil, it also needs to be rechecked whether the inspection space is still sufficient. For old units arranged against the wall, it may be difficult to extract the filter after modification. Please refer toWhen a horizontal air-conditioning box is arranged against a wall, which side should be left for inspection?。

For old units transported in sections, it is necessary to confirm the status of the on-site connection joints. Please refer toHow to identify the assembly sequence for segmented transportation of combined air-conditioning boxes? . Whether the original lifting points or foundation can withstand the added weight also falls within the scope of structural verification.

The remaining space and air volume pressure need to be rechecked

The internal cross-section and length of the old box determine whether it can accommodate new functional sections after renovation. When it is planned to increase the filtration level, the number of coil rows or chemical filtration sections, the resistance will increase, and whether the original fan and box can withstand it needs to be recalculated. When the air volume increases, the original box cross-section may cause the wind speed to be too high, affecting filtration and coil performance.

How to form internal resistance, please refer toWhat functional segments should be included in the internal resistance of the air conditioning box? ;How to establish the fan pressure budget, please refer toHow is the total pressure of the air conditioning box fan determined by the internal resistance and external demand? . If the cross-section of the original box is too small, simply replacing the fan may not solve the problem.

When is it necessary to expand the scope of updates?

If the status of the structure is unclear, critical locations are damaged, or new requirements significantly exceed the original design, it should be further evaluated by a professional team and the total cost of retention versus replacement should be compared. The box retention plan must describe the scope of repair, sealing, and post-installation inspections, and the unverified conditions of the original equipment cannot be directly converted into a modification guarantee.

When the scope of transformation is expanded, the control point table, sensor location and function segment sequence may need to be adjusted. Please refer toWhat point tables need to be provided before the air-conditioning box is connected to the building automation system? andOn what basis should the sequence of functional sections of the air conditioning box be determined? . The original control logic of the old unit may not be suitable for the modified configuration.

Aili industrial supporting equipment

When submitting a modification consultation to Aili Industrial, you can attach photos of the inside and outside of the box, original drawings and operating parameters. First complete the box and space verification, and then determine the new component plan. Aili Industrial can combine sheet metal processing and complete machine assembly conditions to evaluate the repair and interface solutions for the retained box; the manufacturing end covers independent research and development and production of motors and fans, control systems, sheet metal, air filters and complete machine assembly. The box structure, new components and on-site interfaces can be checked in the same package, and non-standard repairs or partial replacements can be adjusted according to on-site conditions.

Product form can be viewedAir handling unit andFan box page; clean air supply package can be combinedFFU fan filter unit andEFU equipment end fan filter unit verification; terminal particle filtration can be combinedHEPA/ULPA filter confirmation; when it comes to gaseous pollution control, you can communicate separatelyChemical filter solutions. The specific transformation effect, applicable conditions and delivery scope still need to be verified based on the corresponding configuration data and on-site working conditions. Actual results are subject to on-site leak detection and performance test results.

Submit project parameters:https://ailigy.com/contactus.html

Related questions and answers

If the old cabinet looks intact, can it be kept?
uncertain. Also check frame corrosion, insulation moisture, sealing status and remaining space. An intact appearance does not mean that the structure and insulation are suitable for continued use.

Is it definitely cheaper to keep the cabinet and modify it than to replace the whole machine?
uncertain. If there are many corrosion, insulation or structural problems, the cost of repair may be closer to that of replacement, and the total cost of retaining versus replacing should be compared.

Can Aili Industrial help evaluate the old cabinet?
The box status and modification interface can be checked based on on-site photos, original drawings and operating parameters. The specific plan needs to be confirmed based on the on-site inspection results.

Related articles

1. How to choose between complete replacement of air conditioning box and partial component update?

2. Can the old chemical filter still be used if its frame is rusty?

3. When a horizontal air-conditioning box is arranged against a wall, which side should be left for inspection?

4. What functional segments should be included in the internal resistance of the air conditioning box?

Key points for selection and acceptance inspection