Quick answer
Uneven office temperatures usually come from zoning that no longer matches the layout, poorly placed or faulty sensors, stuck valves or actuators, blocked filters, failed fan coil fans, solar gain on glazed elevations, or heating and cooling setpoints that overlap. Start by mapping which rooms are affected and when, then have an engineer check the units and controls serving those zones.
Map the problem first
Before calling anyone, build a simple picture:
- which rooms or areas are too hot or too cold
- at what times of day, and in which seasons
- which elevation the rooms face
- whether there have been recent fit-out or layout changes
- whether occupants have adjusted local controllers
This record helps an engineer find the cause quickly.
Common causes
| Cause | What happens |
|---|---|
| Zoning that does not match the layout | One unit or sensor serves rooms with very different loads |
| Sensor in the wrong place | A sensor near a window, heat source or return grille misreads the room |
| Stuck valve or failed actuator | A fan coil or VRF unit cannot heat or cool on demand |
| Failed or slow fan | Little air reaches the room even when valves open |
| Blocked filter or grille | Airflow restricted, especially after furniture moves |
| Solar gain | South and west-facing glazed rooms overheat in the afternoon |
| Overlapping setpoints | Neighbouring units heat and cool at the same time, fighting each other |
| Air balance problems | Supply volumes no longer match room needs after changes |
Why overlapping setpoints matter
When neighbouring units have different setpoints or no deadband, one can be heating while the next is cooling. Occupants feel draughts and swings, and energy use rises. Reviewing setpoints and deadbands across a floor is often a quick improvement.
What an engineer will check
- The units serving the affected rooms: filters, fans, valves, actuators and drains.
- Room and return air sensors: location and calibration.
- Controller and BMS settings: setpoints, deadbands, schedules and overrides.
- Airflow at diffusers where balance is suspected.
- Zoning against the current layout.
Quick wins
- Clear furniture and stock away from grilles and units
- Remove unauthorised local overrides and agree a standard setpoint
- Use blinds on sun-facing elevations in summer
- Have filters checked on units serving problem rooms
Next steps
Most uneven temperature problems are fixed through a combination of fan coil servicing and a review of HVAC controls. For persistent problems after a fit-out, an HVAC system assessment checks whether the system still matches the building.
Frequently asked questions
Why is the meeting room always too hot?
Meeting rooms have high occupancy, equipment and often glazing, so their cooling load changes sharply. If they share a zone or sensor with open-plan areas, or if the unit serving them is undersized or faulty, they overheat.
Can partition changes affect HVAC?
Yes. New partitions can leave rooms without supply or extract, put a room on the wrong sensor or split one unit across two spaces. After re-plans, zoning and controls should be reviewed.
UK guidance and references
Primary and industry sources relevant to this subject. Always check the current edition and how it applies to your building.
- Workplace temperatures Health and Safety Executive
- Approved Document L: conservation of fuel and power GOV.UK
This guide is general information for commercial building operators. It does not replace an assessment of your building by a competent engineer. If there is an immediate risk to people, contact the emergency services first.