HVAC and Refrigeration Services in London

Who is J Sons & Co.?

J SONS & CO. is a commercial HVAC and refrigeration contractor with permanent, fully-staffed offices in London. We design, install, maintain and repair air conditioning, heating, ventilation, refrigeration systems, cold rooms and commercial fridge-freezer equipment for offices, restaurants, hotels, retail units, warehouses, clinics, schools and industrial sites across the United Kingdom.

Our London engineers are Gas Safe registered, F-Gas certified and REFCOM Elite accredited. Same brand, same engineering discipline, one directly-employed London team, no subcontractors, no white-labelled work.

Why Commercial Buildings in London Need a Specialist HVAC Contractor

Heating, ventilation, air conditioning and refrigeration are the four most expensive systems to get wrong in any commercial building. An oversized chiller wastes power for fifteen years. An undersized cold room loses stock every week. A non-compliant refrigerant install can void insurance and trigger a regulatory fine.

The difference between a working HVAC system and an expensive headache is rarely the equipment; it is the contractor. Specification, heat load calculation, refrigerant pipework, electrical isolation, commissioning and documentation are where projects succeed or fail. J SONS & CO. operates as a commercial-only HVAC contractor because that depth of experience is the only thing that consistently delivers systems that perform on day one, year one and year ten.

In London, this means working to BS EN 378, F-Gas regulations, Building Regulations Part F and Part L, CIBSE guidance and Gas Safe requirements.

Our HVAC and Refrigeration Services

1. Air Conditioning Installation

We install split, multi-split, cassette, ceiling-suspended, ducted, and VRF/VRV air conditioning systems for commercial buildings of every scale, from a single 12,000 BTU back-office cassette to 300kW multi-floor VRF arrays. In London, our F-Gas certified engineers work with Daikin, Mitsubishi Electric, Toshiba, Panasonic and LG to deliver installations that meet Part L energy efficiency requirements and F-Gas refrigerant compliance from quotation through to handover.

2. Air Conditioning Maintenance

A planned preventative maintenance contract (PPM) is how a £40,000 system avoids a £4,000 emergency. We offer PPM contracts on a quarterly, half-yearly or annual cycle depending on system type, runtime, and operating environment. London commercial systems typically run on twice-yearly servicing.

Every service visit includes filter cleaning or replacement, condensate drain clearance, coil inspection, refrigerant pressure verification, electrical torque check, fan motor inspection and a written condition report. F-Gas logs in London are kept on file and produced for audits on request.

3. Air Conditioning Repair

Cooling failures rarely happen on a quiet day. Our London emergency response covers all M25 boroughs with same-day attendance on most call-outs. 

Common faults we diagnose and repair include refrigerant leaks, compressor failures, fan motor seizure, capacitor failures, PCB damage, condensate pump faults, sensor faults and low-pressure cut-outs. Our vans carry common spares for Daikin, Mitsubishi Electric, LG, Trane, Carrier and York, so most repairs are resolved on the first visit. F-Gas certified leak detection and repair is standard in London.

4. Heating Systems

In London, we design, supply and install commercial gas boilers, electric boilers, air source heat pumps, ground source heat pumps and underfloor heating systems. All gas work is carried out by Gas Safe-registered engineers, with CP12 landlord certification issued on completion where required. We work with Worcester Bosch, Vaillant, Viessmann, Ideal Commercial and Remeha. Heat pump installations are designed to MCS standards where the client wants access to BUS funding.

5. Ventilation Systems

Mechanical ventilation is now compulsory in the majority of new and refurbished commercial buildings. In London, we install MVHR (mechanical ventilation with heat recovery), kitchen extract systems, toilet exhaust systems and full ducted commercial ventilation compliant with Building Regulations Part F, Approved Document L2, and CIBSE TM52 guidance.

6. Refrigeration Systems

We design, install and maintain commercial refrigeration for restaurants, supermarkets, hotels, cafes, dark kitchens, butchers, fishmongers, pharmacies and central production kitchens. London projects include integral and remote condensing systems for high-street retail.

Every system is sized to the actual product load, not over-specified to pad the quote, not under-specified to win the job. Our refrigerants are F-Gas compliant in the london. R290, R454C, R448A and R449A are common in our current specifications; high-GWP gases like R404A and R22 are phased out of our work.

7. Cold Rooms and Walk-in Freezers

Cold rooms are one of the easiest installations to get wrong and one of the most expensive to fix afterwards. We design cold rooms from 4m³ catering units up to 500m³ industrial cold storage, starting every project with a proper heat load calculation, product type, throughput, ambient, door openings per hour, internal lighting, equipment load, defrost regime, and insulation U-value.

London cold rooms are designed to UK food standards and HACCP. We use Foster, Gram, Williams and Porkka equipment, with polyurethane insulated panels rated to the temperature class required.

8. Fridge Freezer Repair and Maintenance

Commercial fridges and freezers fail in predictable ways: door seals degrade, condenser coils block with dust and grease, evaporator fans seize, thermostats drift, drain heaters fail, and gaskets perish. We service and repair every major commercial brand across London, Foster, Williams, Gram, True, Polar, Blue Seal, Electrolux, Hoshizaki, Precision, usually same-day for emergency call-outs and on a scheduled plan for ongoing maintenance.

Sectors We Serve

Our commercial HVAC and refrigeration work spans the full breadth of the london commercial market

Restaurants, cafés, dark kitchens, fine dining, hotel groups, boutique hotels, supermarkets, convenience stores, butchers, bakeries, central production kitchens, pharmacies, healthcare clinics, dental practices, GP surgeries, veterinary surgeries, private hospitals, schools, nurseries, universities, gyms, leisure centres, hair salons, beauty clinics, offices, co-working spaces, retail units, showrooms, warehouses, distribution centres, data rooms, server rooms, places of worship, listed buildings, embassies, residential blocks, and luxury residential homes.

If your sector is not listed, ask. We have almost certainly delivered a similar project.

Our Credentials, Certifications and Compliance

This is what separates a qualified commercial HVAC contractor from a general fitter. These credentials protect you legally, technically and financially, and they are the credentials a client uses to verify a contractor

United Kingdom; London Office

• Gas Safe Registered (commercial gas heating)
• F-Gas Company Certificate (refrigerant handling)
• Individual F-Gas qualifications held by every refrigerant engineer
• REFCOM Elite registered
• NICEIC approved electrical contractor (Part P compliant)
• CHAS accredited (health and safety pre-qualification)
• ISO 9001 quality management procedures
• ISO 14001 environmental management procedures
• £10m public liability insurance
• Compliance with BS EN 378, Building Regulations Part F and Part L, CIBSE TM44 and TM52, HSE refrigerant guidance

How We Work: From First Call to Handover

Every HVAC and refrigeration project at J SONS & CO. follows the same six-step process regardless of size.

1. Site survey. A qualified engineer attends your site in person, in London, carries out a video survey for smaller jobs. We measure the space, identify service constraints, photograph existing infrastructure and discuss operational requirements.
2. Heat load calculation and design. We calculate the actual heating or cooling load using room dimensions, occupancy, glazing area and U-value, lighting load, equipment load and the relevant ambient design conditions. Specifications are matched to the load rather than oversized to inflate the quote.
3. Written quotation. A fully itemised quotation including equipment, labour, ancillaries, refrigerant, electrical works, builders’ works, commissioning, certification and warranty. No hidden costs and no last-minute extras.
4. Programme and works. Once approved, we issue a programme of works, RAMS (risk assessment and method statement), and a single named project manager for the duration.
5. Commissioning and certification. On completion, the system is commissioned to the manufacturer’s specification. You receive F-Gas certificates, electrical certificates, gas safety certificates (where applicable), and a full O&M (operations and maintenance) pack.
6. Aftercare. All new installs come with the manufacturer’s warranty (typically five years on equipment) and one year on workmanship as standard. PPM contracts are available immediately on handover for ongoing maintenance.

HVAC Services Across London

Our London team covers all 32 London boroughs and the City of London. Active project areas include the City, Canary Wharf, Mayfair, Soho, Shoreditch, Holborn, King’s Cross, Camden, Westminster, Kensington, Chelsea, Hammersmith, Fulham, Battersea, Vauxhall, Wandsworth, Clapham, Greenwich, Stratford, Wembley, Croydon, Bromley and Romford. Out-of-London projects within the M25 corridor, Watford, St Albans, Slough, Reading, Guildford, Sevenoaks and Dartford, are covered on request.

Same-day emergency response is standard inside Zones 1 to 4. Next-working-day response is standard for Zones 5 and 6 and Greater London.

Why Commercial Clients Choose J SONS & CO.

Directly-employed team. We staff and run our own London operation. No subcontractor partners, no white-labelled work, no inconsistent standards.

Commercial-only focus. We do not chase domestic call-outs. Every engineer in our team works on commercial systems daily. That depth shows in the diagnosis, the design and the documentation.

Single-contractor accountability. HVAC, heating, refrigeration, ventilation and cold rooms, all delivered in-house. When something needs warranty attention, there is no finger-pointing between trades.

Honest specification. Systems are sized to the actual load. Oversized AC short-cycles, waste energy and fail early. We have inherited too many badly specified installations from other contractors to repeat the mistake.

Documentation built for auditors. F-Gas logs,  electrical certificates, gas certificates, O&M packs, asset registers, supplied as standard, not on chase-up.

Real engineers on the phone. When you call, you reach someone who understands the system. Diagnosis often starts on the call, before the van leaves.

Frequently Asked Questions

What is F-Gas certification, and why does it matter in London?

F-Gas (Fluorinated Greenhouse Gas Regulations) is UK law governing the handling of refrigerants in air conditioning and refrigeration equipment. Any company installing, servicing or decommissioning HVAC equipment with fluorinated refrigerants must hold an F-Gas company certificate, and individual engineers must hold personal F-Gas qualifications. J SONS & CO. holds both. Hiring an uncertified contractor is illegal, uninsurable and a regulatory liability.

How quickly can you respond to an emergency HVAC failure?

In London, same-day response is the standard target inside the M25. 

Do you supply the equipment or only install it?

Both. We supply equipment from every major manufacturer we work with at competitive trade prices, Daikin, Mitsubishi Electric, Toshiba, Panasonic, LG, Trane, Carrier, York, Worcester Bosch, Vaillant, Viessmann, Foster, Williams, Gram and Polar. If you have already bought equipment, we will install and commission it under our installation warranty.

Can you take over an existing PPM contract from another provider?

Yes. We carry out a takeover survey, document the current condition of every unit, and then enter a PPM contract from a known baseline. This protects both parties, you get a clear starting record, and we are not liable for pre-existing faults.

Do you work on listed buildings in London?

Yes. Listed-building HVAC work in London requires sympathetic design, concealed pipework, low-impact equipment placement, and often planning or listed building consent. 

Can I get a quote without committing to anything?

Yes. Site surveys and written quotations are free for commercial enquiries. We do not take a deposit until you have signed off on the specification and the programme of works.

Request a Quote

For London projects

Phone: +44 20 8050 7969

Email: info@jsonsco.com

Address: 222a Preston Rd, Wembley HA9 8PB, United Kingdom emergency line 24/7.

Or use our contact form, commercial enquiries are answered within one working hour during office hours.