Choosing the right type of commercial air conditioning
Commercial air conditioning is not one product. The right system depends on the size of the space, how many separate zones need different temperatures, and how much heat the building gains.
| System | Best for | Things to weigh up |
|---|
| Single split | One room or a small shop | Simple and low cost, but one indoor unit per outdoor unit |
| Multi-split | A few rooms sharing one outdoor unit | Fewer outdoor units on the wall or roof; limited number of indoor units |
| VRV / VRF | Offices, restaurants, hotels and larger buildings with many zones | Many indoor units on one system; some can heat and cool different zones at once |
| Ducted | Open-plan areas where ceiling cassettes or wall units are unwelcome | Concealed units; needs ceiling void space for ductwork |
| Central plant (chilled water) | Large or complex buildings | Chillers, pumps and air handling units; higher complexity and maintenance |
| Close control | IT rooms and other rooms needing tight temperature and humidity | Designed for continuous, precise cooling |
We design and install central plant and ducted systems with heating, humidification or dehumidification, filtration and heat recovery, plus VRV/VRF systems with ceiling cassette or concealed fan units. For a side-by-side comparison read VRF or split system air conditioning: which is right for a commercial building?.
How a system is sized
Cooling load is the amount of heat that has to be removed to keep a space comfortable. It comes from four main places: heat arriving through the building (sun on glazing, roofs and walls), people, lighting and equipment, and fresh air brought in for ventilation. A shop with a big south-facing window and a busy till area has a very different load from an interior office of the same floor area.
An undersized system never keeps up on a hot day. An oversized one cycles on and off, controls humidity poorly and wastes energy. That is why we survey and calculate rather than quote from floor area alone, and why the type of use (restaurant, office, retail, server room) matters to the design.
Restaurants and commercial kitchens
Air conditioning in a restaurant has to work with ventilation, not against it. Dining areas lose cool air to the kitchen extraction, and strong draughts across the pass or line can disrupt the capture of cooking fumes. HSE advises that where cooler air is needed in a kitchen it can be provided by balanced make-up air, by air conditioning, or by fixed fans that do not affect the efficiency of extraction. Local free-standing fans, by contrast, can disturb extraction. We design the air conditioning and the kitchen ventilation together so they do not fight each other. See our guide to restaurant air conditioning.
Energy efficiency
Modern systems use inverter compressors that match their speed to the load in the room instead of switching fully on and off. By matching compressor speeds to the cooling or heating load of a room, up to a 30% reduction in energy consumption can be achieved. Other savings come from good controls (schedules, set-back, occupancy sensing), correct zoning, heat recovery where simultaneous heating and cooling is needed, and regular maintenance, since dirty coils and filters make plant work harder. Our environment page explains our approach to R410A refrigerant and energy.
Refrigerants and F-gas rules
Most commercial air conditioning contains fluorinated gases (F-gases). Under GOV.UK's F-gas guidance, operators of equipment above set thresholds must have it leak-checked by a suitably certified person at set intervals, and must repair leaks as soon as possible. For example, GOV.UK's guidance sets leak-check intervals of every 12 months for equipment containing at least 5 tonnes of CO2 equivalent, every 6 months from 50 tonnes, and every 3 months from 500 tonnes, with intervals doubled where a leak detection system is fitted. Check the current GOV.UK guidance because thresholds and wording can change. Older systems that use R22 refrigerant can no longer be serviced with R22, so replacement is often the sensible route; we install replacement systems at competitive rates with minimum disruption. Our F-Gas guide for commercial air conditioning explains what operators should do.
Installation, commissioning and handover
We survey the building, agree the design and system layout, install indoor and outdoor units and pipework, test the pipework and system to BS EN 378, and commission before hand-over. Work is planned to minimise disruption, which matters in trading restaurants, offices and shops. After hand-over we offer planned maintenance so the plant stays efficient and compliant.
What to ask before you buy
- How was the cooling load calculated?
- Which refrigerant does the system use, and how much is in the circuit?
- Who will carry out the leak checks, and are they suitably certified?
- What will the running costs look like, and how are controls set up?
- Where do indoor and outdoor units go, and how will noise and condensate be handled?
- What maintenance does the manufacturer require to keep the warranty valid?
