An architect studio overheats from afternoon glass and from screens left on, not from a dense call-floor of people. Size the glazed wall and the monitors. A single west-facing room with eight desks is a different problem from a deep open office with internal gains only. Keep air off necks at the drawing table, and do not put the indoor unit where it washes a monitor and causes complaints you will blame on the software. HSE temperature guidance is the workplace duty. There is no legal maximum.
Four o'clock on the west glass
West and south glazing at 4pm can exceed the heat from the people. Say which elevation, and whether blinds actually get used. A survey at 9am with the blinds down will undersize the room. Screens and a plotter add a steady gain. A meeting table used twice a week does not double the plant. Photos of the glazed wall in the afternoon, the desks and the screen layout are the useful record. You do not need a full building model to get an honest first reply.
One zone with a wall unit or a cassette can be right for a single studio floor. HSE temperature guidance is the workplace duty. There is no legal maximum. Keep throw off necks and off monitor faces. Use a moderate fan and aim along the ceiling so paper stays flat.
Boards, shut crit rooms and trunking on a drawing
People sit still and look at fine lines. A draught on the wrist or a flap that chatters is more annoying here than in a shop. Low or medium fan, vane along the ceiling, and a setpoint you do not chase down to 16C. The kilowatts are fixed. The fan is the comfort control. Several private crit rooms with shut doors need their own indoors or they stay warm. Do not rely on a door propped into the studio.
Models, trace and a spray booth, if you still spray, do not belong in the cooling story. Sprays need extract. The split recirculates. Paper that must lie flat should not sit in a high-fan path. Say where the boards are. The studio will judge the trunking. Put it on a drawing before install day, on a wall that is not the elevation you show clients. The outdoor unit needs a lawful place, service access, and a noise check to the flat next door or the meeting room window. F-gas certification applies. If you cool a whole floor and the rated output crosses the inspection line, use the GOV.UK air conditioning inspections page. A single room may not. Energy Saving Trust's air-to-air page is a useful description if you also want heating from the same units on a small domestic-scale system. A large office may be a commercial range instead. Let the survey say which.
Frequently asked questions
Why does the studio cope in the morning and fail at 4pm?
The glass has not peaked yet at 9am. Size for the afternoon sun you actually get, with blinds as they are really used.
Will the airflow bother people at screens?
It will if it hits faces or makes paper lift. Aim along the ceiling and use a moderate fan. The setpoint does not have to be extreme.
Can one cassette cover desks and a closed meeting room?
No. A shut door leaves the meeting room on its own. Give it a zone or accept it will not hold the setpoint.
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How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.