Gallery office not cold: return air blocked by new display partition

A small gallery office in the Museum area became warm after display works. The unit still ran, but the room never settled. In civic-district spaces with fit-out changes, airflow layout often needs checking before the aircon body is blamed.

By Team Snowflake | Updated 28 Jul 2026

Case summary

Toshiba Cassette4 years oldOfficeMuseum, Singapore

Concern: The gallery manager expected a gas issue because the cassette ran but the office stayed warm.
Found: New display partition blocking return air back to the cassette
Key check: Checked room airflow paths after the fit-out change
Result: Once the return path was opened, the office cooled more evenly across both sides of the partition. No gas top-up or cassette repair was needed for this case. The display layout, not the cassette hardware, was the useful correction.

What we were told

The gallery office was fine before a new display partition was installed. After the fit-out, the unit ran continuously, but the area behind the partition stayed warm and staff started lowering the temperature every afternoon. Nothing obvious had changed on the unit itself, so the timing of the layout work mattered.

What we checked

Because the symptom appeared after a layout change, we looked at the room before assuming an internal fault. The cassette was clean enough to move air, so we traced where the air went. The new partition sat close to the return path and changed how warm room air moved back to the unit.

The cassette started and responded normally.
Supply air reached the front of the room but did not circulate behind the partition.
Warm return air was trapped on the wrong side of the display wall.
Filter and visible coil condition did not explain the sudden change.

What we found

The display partition disrupted the air loop. Cool air left the cassette, but warm air from the occupied side could not return cleanly to the intake. The unit therefore kept cooling the air near itself while the working area stayed warm. Nothing had to be broken inside the cassette for the room to feel uncomfortable. The timing after the fit-out, plus the uneven room feel, matched a layout issue better than gas loss or a failed part.

What fixed it

We advised adjusting the partition opening and return path before spending on parts. Where the display layout could not move much, we suggested keeping a clear high-level gap and avoiding tall storage near the cassette intake. We also explained that future layout changes should be checked against air paths, not just furniture clearance. The recommendation was to correct circulation first, then monitor whether the cassette could hold the room again.

Outcome

Once the return path was opened, the office cooled more evenly across both sides of the partition. No gas top-up or cassette repair was needed for this case. The display layout, not the cassette hardware, was the useful correction.

What this case teaches us

Fit-out changes can create an aircon fault without breaking the unit

A cassette needs a clear path for air to leave and return. New partitions can block that loop.
If cooling changed after renovation or display works, the room layout is part of the diagnosis.
Before approving parts or gas work, ask whether the technician checked supply and return air paths around the new layout.

Questions this case answers

Office got warm after a new partition went up: is the aircon faulty?

Nothing had to break for the room to feel wrong. In this Museum-area gallery the cassette started and responded normally, but the new display partition sat close to the return path. Cool air reached the front of the room while warm air behind the wall could not get back to the intake, so that side stayed uncomfortable.

Aircon runs non-stop but half the office stays warm. What is going on?

It keeps cooling the air it can reach. With the return loop interrupted, the cassette recirculated air near itself while the occupied side stayed warm, so the set point was never met and staff kept lowering the temperature each afternoon. Filter and visible coil condition did not explain a change that sudden.

Do I need a gas top-up if only part of the office is warm?

Uneven cooling across a room points at air movement rather than refrigerant. A gas shortfall weakens the whole space, not one side of a partition. Adjusting the opening and clearing the return path was the recommendation here, with parts held back until circulation had been corrected and the room monitored.

What should be checked before a shop or gallery fit-out?

Where air leaves the unit and where it comes back. Furniture clearance is the usual measure, but a cassette needs an unbroken loop, so a tall display or storage placed near the intake changes performance without touching the equipment. Keeping a clear high-level gap was the practical compromise where this layout could not move much.

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