Office and commercial air conditioning in London

In multi let London buildings, from City towers to converted warehouses in Clerkenwell and Shoreditch, the landlord usually controls the roof, the risers and any plant space. Expect to need a licence for alterations, drawings, method statements and proof of the installer's F-gas certification and insurance. Some buildings have a preferred contractor list or a landlord's mechanical engineer who reviews the design.

Planning is stricter for commercial property too. The permitted development right for heat pumps covers houses and blocks of flats only, so new outdoor plant on a shop or office normally needs planning permission. Central boroughs set firm noise limits for plant. Westminster's noise guidance, for example, asks that plant noise at the nearest home stays 10 dB below the lowest background level in noisy areas.

Common options for London offices are:

• Ceiling cassettes: square units set into a suspended ceiling that blow air four ways, good for open plan floors.
• Ducted units: hidden in the ceiling void with only grilles showing, good for meeting rooms and premium fit outs.
• Wall mounted units: simple and lower cost for small offices, studios and treatment rooms.
• Multi zone or VRF style systems: one outdoor unit serving many indoor units, with each room controlled on its own.

The right answer depends on ceiling height, how many people use each room, glazing and the computers and screens that add heat.

Two sets of rules apply to many office systems. First, under the Energy Performance of Buildings regulations, air conditioning systems with an effective rated output of more than 12kW must be inspected by an accredited energy assessor at least every five years. This is the TM44 inspection, explained in the government guide.

Second, F-gas rules require regular leak checks on equipment that holds refrigerant equal to 5 tonnes of CO2 or more, with records kept by the operator. The frequency is set out on gov.uk. Larger multi zone systems often pass that line. Only an engineer with an F-gas qualification, working for an F-gas certified company, can carry out the work.

Most London offices cannot shut for a week. Installs can be phased floor by floor, noisy core drilling can be booked for early mornings or weekends where the building allows, and indoor units can be fitted after hours to keep desks usable. We agree working hours, lift bookings and loading bay slots with the building manager before starting, because in the City and Canary Wharf those rules are strict.

Not every commercial job is an office. Shops on London high streets, beauty and treatment rooms, dental and medical clinics, and creative studios all need cooling that suits how the space is used. A treatment room needs quiet, gentle airflow. A shop with a glazed front needs strong cooling near the door. Studios with lighting rigs or equipment need more capacity than the floor area suggests. In mixed use buildings with flats above, noise at the residents' windows is usually the deciding planning issue, so the outdoor unit position and any acoustic screen are agreed early.