Air Conditioning Installation London are commercial air conditioning and refrigeration engineers and are REFCOM F-Gas registered. We cover all 32 London boroughs, the City of London and M25 towns. Commissioning should be planned around the equipment specification, site readiness and intended stock temperatures. Call 07427 826446 to discuss your system, its refrigerant and your handover date. You receive a fixed written quote before work starts.
Define the Duty Before the First Start
Commissioning begins with an agreed operating brief rather than a generic temperature setting. A chilled preparation room, freezer store and display cabinet have different requirements for product temperature, door openings and recovery time. The equipment schedule, manufacturer’s instructions, refrigerant designation and design ambient conditions establish the reference points. Any required alarm outputs, remote monitoring connections or interfaces with other building systems should also be identified before start-up, so the final handover reflects how the business will actually operate.
Site readiness matters just as much as the equipment specification. The electrical supply and isolators must be ready, evaporator and condenser air paths unobstructed, condensate routes complete, and cold-room doors and seals functional. For a restaurant fit-out in Soho or a supermarket refurbishment in an outer borough, other trades may still be working nearby. Dust, temporary coverings or unfinished ventilation can invalidate operating readings. Agreeing which areas are complete helps prevent an apparently successful start-up from masking unsuitable site conditions.
Establish Refrigerant-Circuit Readiness
Before refrigerant is introduced or compressors are started, the commissioning engineer needs the relevant circuit preparation records. Depending on the system and work completed, these include strength and tightness test results, evacuation readings and confirmation of the specified charge. Pressure testing must follow the applicable design and manufacturer’s limits; oxygen must never be used. Evacuation removes air and moisture, which can otherwise contribute to excessive condensing pressure, ice at expansion devices and deterioration of refrigerant oil.
The refrigerant shown on the equipment documentation determines the charging method, pressure limits and safety precautions. R448A and R449A are blends and are not interchangeable simply because their applications overlap. R744 carbon dioxide operates at substantially different pressures, while R290 propane introduces flammability considerations. Confirm the refrigerant when requesting commissioning so the scope and competence requirements can be established. For fluorinated refrigerants, applicable F-Gas requirements govern handling, leak prevention and records; statutory leak-check duties depend on the refrigerant, charge and equipment.
Set Up the Refrigeration Cycle Under Load
During the controlled first run, operating readings need to be interpreted together. Suction and discharge pressures, refrigerant line temperatures, compressor current and supply voltage help establish whether the system is operating within its intended envelope. Superheat and subcooling are assessed against the manufacturer’s requirements, using the appropriate dew-point or bubble-point reference for refrigerant blends. A sight glass alone is not a reliable basis for deciding charge quantity, and adding refrigerant cannot compensate for restricted airflow or an incorrectly configured expansion valve.
Commissioning also establishes the behaviour of evaporator fans, condenser fans, solenoid valves and capacity controls where fitted. Incorrect fan rotation, closed service valves, unsuitable pressure-control settings or a misplaced sensing bulb can prevent stable operation from the outset. Readings should be recorded with their operating context, including ambient temperature and load. An empty cold room can demonstrate initial pull-down, but it does not by itself prove performance with warm incoming stock, frequent door openings or the full design heat load.
Prove Temperature Control, Defrost and Alarms
A controller display is only useful if its probe location, reading and configuration are appropriate. Commissioning establishes the temperature setpoint, switching differential, compressor restart delay and alarm thresholds against the intended duty. Where relevant, displayed temperatures are compared with a suitable reference instrument. High-temperature alarm delays should accommodate legitimate events such as defrost without concealing a sustained loss of cooling. Door switches, alarm contacts and monitoring interfaces also need functional proving where they form part of the agreed system.
Defrost requires more than selecting a convenient clock time. The method, frequency, termination temperature, maximum duration, drainage period and fan restart conditions must suit the evaporator and application. Poor settings can leave ice on the coil or introduce unnecessary heat into the store. In England, food subject to chilled temperature-control requirements generally needs to be kept at 8°C or below, with exceptions; setting refrigeration at 5°C or below helps allow a margin. Air-temperature commissioning does not replace the operator’s food-temperature checks and food safety procedures.
Account for London Site Conditions and Acceptance Limits
London premises can place refrigeration equipment in difficult surroundings: basement kitchens with limited heat rejection, enclosed rear yards, rooftop plant areas or shared service spaces. Commissioning must consider the conditions at the condenser, not just the temperature inside the refrigerated space. Recirculated hot discharge air can increase condensing pressure and reduce capacity. Kitchen extract systems and building ventilation may also affect plant-room conditions, so relevant building systems should be operating normally when representative performance readings are taken.
Acceptance should distinguish what has been demonstrated from what remains unproven. A system commissioned on a cool day has not necessarily demonstrated summer peak-load performance, and an unloaded cabinet has not proved recovery during a busy lunch service. Record the ambient conditions, operating load, achieved temperatures and any outstanding constraints. Where a load demonstration or monitoring period is needed, agree it explicitly. This gives the customer a clear basis for accepting the system rather than relying on a brief observation that it feels cold.
Complete the Handover and Arrange Commissioning
A useful commissioning handover gives the operator a starting point for running the equipment. The agreed record should identify the system and refrigerant, final controller settings, relevant operating readings, functional checks and outstanding items. Staff need to understand alarm meanings, loading restrictions and any waiting period before stocking. Initial pull-down is not permission to load unrestricted quantities of warm food. Commissioning establishes operational readiness against the agreed scope; it does not replace the business’s HACCP controls or ongoing temperature records.
To discuss commissioning, call Air Conditioning Installation London on 07427 826446. We are open seven days a week, 07:00–21:00, and cover all 32 London boroughs, the City of London and M25 towns. Have the site address, equipment details, refrigerant, available documentation and proposed handover date ready. Mention access restrictions and whether the premises will remain trading. A fixed written quote is provided before work starts. If your project also involves a new installation, a free site survey is available for installations.
Book an engineer
Fixed written quote before any work starts. 7 days a week, 07:00–21:00.
Frequently asked questions
When should commercial refrigeration commissioning take place?
Plan commissioning before the intended stocking or opening date, once the system and its supporting services are ready. Power, drainage, ventilation, doors and controls must be sufficiently complete for meaningful operation. Allow time to resolve outstanding items and demonstrate pull-down. Starting the equipment for the first time immediately before a delivery leaves little room to address settings or site conditions that prevent acceptance.
Can refrigeration installed by another contractor be commissioned?
Discuss the proposed handover scope before booking. Commissioning depends on access to equipment specifications, wiring information and relevant circuit preparation records, regardless of who completed the work. Missing evidence of pressure testing or evacuation cannot simply be replaced by observing the system running. Send the available documentation and explain what has already been completed so readiness, responsibilities and any additional work can be established.
Does REFCOM registration mean every refrigeration system has the same requirements?
No. Air Conditioning Installation London is REFCOM F-Gas registered, but the requirements for an individual system depend on its refrigerant, charge, construction and application. F-Gas duties are not the same as the safety requirements for propane or carbon dioxide systems. Provide the refrigerant designation and equipment details at enquiry stage so the appropriate commissioning scope, handling requirements and documentation can be identified.
What temperature should a freezer reach before it is stocked?
Use the equipment specification, product storage instructions and your food safety plan rather than a universal controller setting. Many frozen-food applications use a storage target of −18°C or colder, but the required air setpoint and alarm settings depend on the system and products. Confirm stable operation and the permitted loading conditions before stocking. Equipment intended to store already-frozen food may not be designed to freeze fresh products.
How long does commissioning take, and what affects the quote?
The time required depends on system size, the number of circuits and controllers, documentation, site readiness and the agreed performance demonstration. Cold-room pull-down, defrost proving and alarm integration can require longer observation than a simple first start. Provide the equipment schedule and proposed acceptance requirements when you call 07427 826446. A fixed written quote is provided before work starts; no standard duration should be assumed.