What is wrong? › Commercial HVAC
Thermostat wars are usually a zoning or airflow problem, not a people problem
OSHA recommends 68 to 76 F and 20 to 60 percent humidity for indoor work. It is guidance, not a rule, but it is the number to aim at before anyone argues.
What is probably happening
- One thermostat controls a big space with a sunny side and a shaded side, or a kitchen on one end and a dining room on the other.
- Diffusers were never balanced, so the room nearest the unit freezes and the far end cooks.
- A thermostat sitting in a bad spot: above a copier, in sun, next to a door, or in a room nobody uses.
- Staff turning the setpoint up and down all day, which makes the unit chase itself.
Do this in the next five minutes
- Pick one setpoint inside the OSHA range and lock the thermostat with a cover or a code.
- Put a cheap thermometer in the hottest and coldest spots for three days and write down readings at 10 am and 3 pm.
- Look at the vents: which are wide open, which are shut, which blow hard.
- Book a contractor visit with your readings and ask for an air balance and a thermostat location check.
- Ask about a second zone or a ducted mini split for the problem room if balancing does not fix it.
Do not
- Do not close more than a couple of diffusers to fix one hot spot. Too many closed vents raise duct pressure and can ice the coil.
- Do not add space heaters under desks in a cooled space without telling the contractor. They fight the system and load circuits.
- Do not buy a smart thermostat as the fix before the airflow is sorted.
Who to call
A licensed commercial HVAC contractor, ideally one who does test and balance
Balancing diffusers, relocating a thermostat or adding a zone damper is controls and airflow work on your existing unit.
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What it should cost
$100 to $250 per hour
HVAC labor for balancing, thermostat relocation or a zone damper; parts extra. No neutral figure for commercial zoning was found
Source: Angi, HVAC repair cost, updated August 2026. View source
National published range, not a quote for your job. The full cost table for this trade is on the commercial hvac page.
Ask this contractor, on the phone, before anyone comes out
Tap each one as you ask it.
- Can you measure airflow at each diffuser and balance them, and give me the before and after numbers?
- Is the thermostat in the right place, and what would moving it cost?
- Would a zone damper or a separate small unit for the problem room make sense, and what is the rough cost of each?
- Is the unit the right size for this space, or is it short-cycling?
End the call if
- A new unit proposed as the fix for a comfort complaint with no airflow measurements.
- A 'balance' that consists of closing vents.