Commercial HVAC Engineers + Contractors

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  Top common faults we see:

• Dirty filters / coils causing poor airflow and high running costs
• Refrigerant leaks (loss of performance and system damage risk)
• Failed capacitors/contactors (especially splits/VRF outdoor units)
• Fan / motor / bearing failure
• Blocked condensate drains (water leaks, ceiling damage)
• Control / BMS issues (wrong setpoints, sensors out of calibration)
• Low water flow / air locks in heating/cooling circuits

Classic signs include:

• Hot / cold spots around the building
• Humidity issues (too damp = mould risk / too dry = discomfort)
• Stuffy air / headaches (poor fresh air / poor filtration)
• Condensation on windows or ceilings
• Unusual odours (mould, drain smells, stale air)
• Noisy operation (fans, bearings, loose panels)
• High energy bills with the same usage
• Frequent callouts for resets / breakdowns

A poorly maintained HVAC system creates real risk in 5 areas:

1. Breakdowns and downtime (loss of heating/cooling = business disruption)
2. Higher energy costs (dirty filters/coils and incorrect controls cause inefficiency)
3. Poor air quality (dust/mould/bacteria build-up, especially with blocked filters/drains)
4. Compliance risk (F-Gas leak checks, TMVs, ventilation rates)
5. Reduced lifespan (premature failure of compressors, motors, fans, pumps

Key UK regulations commonly linked to HVAC include:

• F-Gas Regulations (refrigerant leak checking, handling, records, certified engineers)
• Health & Safety at Work Act 1974 (general duty of care)
• COSHH (chemicals like coil cleaner / water treatment)
• Workplace (Health, Safety & Welfare) Regulations 1992 (ventilation requirements)
• Building Regulations (especially Part F ventilation / Part L energy efficiency)
• HTM/HBN guidance in healthcare environments (if applicable)
• Legionella control (HSE ACOP L8 & HSG274) for systems like AHU humidifiers /      water systems

A simple way to group them is:

1. Split Systems: Indoor unit + outdoor condenser (cooling/heating)
2. Multi-Split Systems: One outdoor serving multiple indoor units
3. VRF/VRV Systems: Variable refrigerant flow systems for multiple zones, high efficiency
4. Central Plant Systems: Chillers/boilers + AHUs/fan coils distributing heating/cooling via water + ductwork

• VRF = Variable Refrigerant Flow (general system type)
• VRV = Variable Refrigerant Volume (Daikin’s branded name for VRF)

Same concept: the system varies refrigerant flow to match demand across multiple indoor units, giving:

• excellent zoning control
• high efficiency
• strong performance for multi-room commercial sites

In the UK, the most common commercial HVAC setups are:

• VRF/VRV systems (very common in offices, schools, hotels, multi-room buildings)
• Chiller + AHU systems (larger buildings like hospitals, large offices)
• Gas boiler + radiators/fan coils paired with DX splits for cooling (very common on mixed-use sites)

It depends massively on capacity, brand and complexity, but as ballpark UK figures:

• Small split system (single room): £1,500 - £4,000 installed
• Multi-split (2–5 indoor units): £5,000 - £15,000 installed
• VRF/VRV systems: £15,000 – £150,000+ installed
• Chiller plant: £30,000 - £300,000+ installed
• AHU (Air Handling Unit): £10,000 - £100,000+ installed