In a product showroom the heat is often the lighting: track, spots and window lights on for the whole trading day, in a tall room with few people. Floor area and a small staff count will undersize it. Survey the lamp load, including older spots if they are still there, and the ceiling space those lights already occupy. Cool the occupied band. If the effective rated output is more than 12 kW, the operator has the TM44 inspection duty on GOV.UK's air conditioning inspections page. Use an F-gas certified company.
Track, spots and a floor that is rarely full
A row of spots over a display can outrun the people standing under it. Ask what is installed, not what a future LED scheme might be, unless that scheme is actually funded and dated. Window bays add solar on top of the lamps. The load stays when the showroom is quiet. Put the lighting schedule in the load. Do not size from staff headcount alone. Include solar on the glazed bays.
Dimmers and switching matter. If every track is on from open to close, that is the design case. If a night set is lower, the comfort plant may still be off, but the survey should not assume a gallery blackout you do not run.
Showroom ceilings are high so the lights can aim. Bring air to the height people stand and sit. Stratification is the failure mode. Staff who meet clients on the floor all day are the HSE comfort question: reasonable workplace temperature, no legal maximum. The product does not need a shop setpoint. People do. A mid 20s target is easier to hold under lights than a cold gallery number.
A ceiling already full of track
Tracks, transformers, fire detection and feature bulkheads steal the cassette space. Measure the void. Leave space in a ceiling already full of track. A ducted run or wall units on side piers may be what the ceiling can take. Condensate must not drip onto a display. Pumps need alarms.
Outdoor plant, landlord or centre-management consent, and power for a system that may be larger than the headcount suggests are the install constraints. Service access has to wait until the showroom can be reached without a ladder over stock. If the lighting is later replaced with lower-heat lamps, the plant will be oversized. That is acceptable if you have said so. It is a surprise if you have not. The lighting load assumed in the selection should be stated, with the throw into the occupied band. An F-gas certified company installs the plant. The hours that matter are the hours the lights are actually on.
Frequently asked questions
Why size a showroom from the lights if it is rarely full?
Because the lights are on all day and the ceiling is high. People are a small part of the gain. A headcount-only figure will leave the floor warm under the track.
Will new LED spots remove the need to cool a showroom?
They can cut the heat if they are really fitted. Until then, survey the lamps that are there. LEDs still add some heat, and the sun on the glass remains.
Can one high-level unit cool a double-height showroom?
Only if it delivers air to the occupied band. A unit lost at the apex often cools the roof space. A cassette in the apex can cool the void and leave the display floor warm, or throw a draught across a polished table. Ask the survey to show where the air goes.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
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.