HVAC Inspection

Per EN 12831, the design heat load must be calculated considering external design temperature for the building location, fabric U-values, ventilation heat loss, and internal heat gains. Radiator output must meet EN 442 test conditions (ΔT 50 K) and be correctly sized for each room. System energy performance must be assessed per EN 15316 series, covering generation, distribution, emission, and control subsystems.

1. Verify heat load calculation per EN 12831 uses correct external design temperature for the site location

2. Confirm radiator sizing matches room heat loss calculations, with output declared per EN 442 at the system design temperatures

3. Check distribution pipework is correctly sized for the design flow rates and system pressure drop

4. Verify flow and return temperatures at the boiler or heat generator match the design specification

5. Confirm thermostatic radiator valves (TRVs) are installed on all radiators except in rooms with room thermostats

- Heat load calculation uses incorrect external design temperature for the site location

- Radiators undersized because EN 442 output at ΔT 50 is assumed but system operates at lower temperatures

- Pipework undersized causing excessive pressure drop and insufficient flow to remote radiators

- TRVs missing or set to maximum, preventing individual room temperature control

Per EN 16798-1, indoor air quality must meet the required category (Category I to IV) based on building use. Ventilation rates must provide adequate outdoor air supply per person and per floor area. Ductwork must comply with EN 1506 (circular ducts) and EN 1507 (rectangular ducts) for material and construction. Air handling unit performance must be verified against the design specification for airflow, pressure, and filtration.

1. Verify design ventilation rates meet EN 16798-1 requirements for the building use category

2. Measure supply and extract airflow rates at each terminal device using a calibrated anemometer or flow hood

3. Check air handling unit filter condition and confirm filter class matches specification per EN ISO 16890

4. Verify ductwork is sealed and supported per EN 1507/EN 1506 requirements

5. Confirm extract ventilation is provided in all wet rooms (kitchens, bathrooms, WCs) at adequate rates

- Ventilation rates below design values due to dirty filters or incorrect fan speed settings

- Ductwork connections not sealed, causing air leakage and reduced system performance

- Supply and extract air flows unbalanced, creating unwanted positive or negative pressure

- Fresh air intake positioned too close to exhaust outlet or pollution sources

- Condensation in ductwork due to inadequate insulation on ducts in cold spaces

Per EN 378-1 to EN 378-4, refrigerating systems must meet safety requirements for design, construction, testing, and operation. Refrigerant charge limits depend on the refrigerant type and system location per EN 378-1 Table C.1. Heat pump performance must be tested per EN 14511 with seasonal efficiency declared per EN 14825 (SCOP for heating, SEER for cooling). F-gas regulations apply to systems containing fluorinated greenhouse gases.

1. Verify refrigerant type and charge are within the limits per EN 378-1 for the system location and occupancy

2. Check compressor, condenser, and evaporator for correct operation and performance against EN 14511 rated values

3. Confirm leak detection system is installed where required by EN 378-3 and F-gas regulation

4. Verify safety devices (pressure relief, high/low pressure switches) are functional and correctly set

5. Review F-gas log records for leak checks, refrigerant additions, and technician qualifications

6. Confirm declared SEER/SCOP per EN 14825 meets project energy performance requirements

- Refrigerant charge incorrect — undercharge reduces capacity, overcharge risks compressor damage

- Leak detection not installed where EN 378-3 requires it for the refrigerant quantity and location

- F-gas records incomplete or leak checks not performed at required intervals

- Condenser airflow restricted by poor siting or adjacent obstructions, reducing cooling capacity

- Seasonal efficiency below declared values due to incorrect controls setup

Rectangular sheet metal ducts must comply with EN 1507 for construction, dimensions, and tolerances. Circular ducts must meet EN 12237. Ductwork air leakage must be within the specified leakage class per EN 15727 (Class A, B, C, or D — higher classes for more demanding applications). Flexible duct connections must be minimised in length (typically max 1.5 m) and must not be kinked or compressed.

1. Verify duct material and gauge comply with EN 1507 (rectangular) or EN 12237 (circular)

2. Check duct joints are correctly sealed with appropriate gaskets or sealant per the specified air leakage class

3. Confirm ductwork supports are spaced per EN 1507/EN 12237 requirements for the duct size

4. Inspect flexible duct connections — verify they are short (max 1.5 m), fully extended, and not kinked

5. Verify fire dampers are installed at all fire compartment boundary penetrations per EN 15650

- Duct joints not sealed, resulting in air leakage exceeding the specified class per EN 15727

- Flexible ducts kinked, compressed, or excessively long, causing high pressure drop

- Ductwork not adequately supported, causing sagging and collecting condensation

- Access doors missing at fire dampers and other components requiring maintenance

- Ductwork damaged during construction and not repaired before concealment

Per EN ISO 12241, thermal insulation for building equipment (heating, cooling, and domestic hot water pipework) must be designed to limit heat loss and prevent condensation. Minimum insulation thickness depends on pipe diameter, fluid temperature, and ambient conditions. Vapour barriers must be provided on cold pipework insulation to prevent condensation forming within the insulation material. All fittings (valves, flanges, bends) must be insulated to the same standard.

1. Verify insulation thickness meets EN ISO 12241 requirements or project specification for the pipe diameter and application

2. Check insulation is continuous with no gaps — all valves, flanges, and fittings must be insulated

3. Confirm vapour barrier is intact on all chilled water pipework insulation, with sealed joints and overlaps

4. Inspect insulation at pipe supports to verify thermal pads prevent compression and cold bridging

5. Verify insulation material fire classification meets EN 13501-1 requirements for the installation location

- Insulation missing on valves, flanges, and fittings — these uninsulated components cause significant heat loss

- Vapour barrier damaged or not sealed at joints on chilled water pipework, allowing condensation to form within insulation

- Insulation compressed at pipe supports, reducing effectiveness and creating cold bridges

- Insulation thickness below specification, increasing energy loss above design calculations

Per EN ISO 52120, building automation and control systems (BACS) must be classified by function (Class A to D, where A is the most energy-efficient). The impact on energy performance must be assessed per EN 15232. Control systems must provide time scheduling, optimum start/stop, weather compensation, and zone control appropriate to the building use. Sensors must be correctly located and calibrated.

1. Verify the BACS class per EN ISO 52120 meets the project specification and regulatory requirements

2. Confirm time schedules are programmed to match building occupancy patterns

3. Check weather compensation curves are set correctly for the heating and cooling systems

4. Verify temperature and humidity sensors are correctly located (away from heat sources, draughts, and direct sunlight)

5. Test alarm functions — high/low temperature, filter differential pressure, plant failure

6. Review trend logging to confirm systems are operating within design parameters

- Time schedules not adjusted for actual building occupancy, causing unnecessary energy consumption

- Weather compensation not commissioned or incorrectly set, overriding design efficiency

- Temperature sensors poorly located (in direct sunlight, near heat sources), giving false readings

- BMS points not connected or labelled incorrectly, preventing effective monitoring

Heating system commissioning must comply with EN 14336, including flushing, filling, venting, and setting design flow rates. Ventilation system commissioning must meet EN 12599, covering airflow measurement, pressure testing, and functional performance verification. Hydronic balancing must achieve design flow rates at all terminal units within acceptable tolerances (typically +/- 10 %). All commissioning results must be recorded and handed over to the building operator.

1. Verify system has been flushed and water quality meets the specification (pH, inhibitor concentration)

2. Confirm heating and chilled water flow rates have been measured and balanced to within +/- 10 % of design per EN 14336

3. Measure supply and extract airflow rates at all terminals and confirm they are within +/- 10 % of design per EN 12599

4. Check all safety devices have been functionally tested (pressure relief, thermostats, flow switches)

5. Review commissioning records — all results must be documented with instrument serial numbers and calibration dates

- System not flushed before commissioning, causing debris to block valves and heat exchangers

- Flow rates not balanced, with terminals close to the pump receiving excess flow and remote terminals starved

- Commissioning records incomplete or not provided for handover to the building operator

- Safety devices not tested during commissioning, remaining in unknown operating condition

- Air trapped in system due to inadequate venting, causing noise and reduced performance