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Ventilation Commissioning & Airflow Test in Ireland
A precise airflow test is essential not only for day-to-day comfort, but also for demonstrating compliance with Irish Building Regulations. Correct testing confirms that each room receives the right air supply and extract and that the system operates efficiently and quietly.
Whether your property uses mechanical ventilation with heat recovery (MVHR/HRV), mechanical extract ventilation (MEV), demand controlled ventilation (DCV) or other continuous systems, proper airflow testing, system balancing, and documentation are now required under Technical Guidance Document Part F (2019) and the NSAI Ventilation Validation Scheme for new dwellings and many major renovations.
In addition, correctly commissioned ventilation supports the energy performance targets set out in TGD Part L (2025).(Conservation of Fuel and Energy – Dwellings), where airtightness, mechanical ventilation and fabric performance are assessed together in DEAP)
What Is an Airflow Test?
An airflow test measures and verifies the volume of air entering and leaving each room through your ventilation terminals. During testing, our engineers use calibrated instruments to record supply and extract flow rates in litres per second (L/s), in line with I.S. EN 14134:2019 and the NSAI Ventilation Validation Scheme requirements.
We then fine-tune each grille, valve and damper so that every room achieves its design airflow. This delivers the right balance between:
- Indoor air quality
- Noise levels
- Energy efficiency and heat recovery performance
Proper airflow testing and balancing:
- Improves indoor air quality by maintaining continuous, controlled ventilation
- Reduces the risk of condensation and mould by limiting indoor moisture levels, a core aim of Part F and S.R. 54 in retrofit projects
- Optimises MVHR/HRV efficiency by avoiding over- or under-ventilation in individual rooms
Well-executed testing and balancing help your home satisfy both TGD Part F (ventilation) and Part L (energy) obligations, provided the system has been correctly designed and installed from the outset
Why Ventilation Commissioning and Airflow Test Matter
Airflow testing confirms that your ventilation system is performing as designed and that the installed system actually matches the design assumptions submitted for Building Control, BER and SEAI documentation.
In Ireland, for systems covered by TGD Part F (2019):
- Airflow rates must be measured at each air terminal device in L/s
- Measured values must be compared against the design calculations and NSAI design sheets
- A competent person must carry out the test using calibrated equipment and record the results in a commissioning report
This commissioning report is typically required for:
- Demonstrating Part F compliance
- BCAR ancillary certification and Assigned Certifier sign-off
- NSAI Ventilation Validation Certificates for mechanical systems
For reference, the NSAI Ventilation Validation Registration Scheme follows I.S. EN 14134:2019 and clearly defines the performance checks, documentation and calibration requirements that must be met before a validator can issue a Ventilation Validation Certificate.
Our Ventilation Commissioning & Balancing Process
1. Preliminary Design Review
Before arriving on site we:
- Review all ventilation design drawings, schedules and specifications
- Check that total general and boost ventilation rates meet TGD Part F requirements for your dwelling type and floor area
- Confirm that the proposed system type (MVHR, MEV, DCV, PSV or intermittent extract) is appropriate for the airtightness level and refurbishment strategy, particularly in retrofit dwellings under S.R. 54
This means we arrive prepared to verify exactly what the design intends to achieve.
2. Site Preparation
On the day of testing, we first prepare the dwelling in line with I.S. EN 14134 / NSAI guidance:
- All external windows and doors are closed
- Background ventilators are set to their intended “normal” operating position
- Internal doors are typically closed to reflect real use and to confirm that the required 10 mm undercut provides adequate transfer air between rooms, as required by TGD Part F 2019
- All controls, including boost functions, are set to the correct mode for testing
We only use calibrated instruments with valid certificates, and we retain these calibration records as part of your final documentation.
3. Visual Installation Inspection
Before switching the system on, we verify that the installation matches the design and manufacturer instructions:
- Duct routes, sizes and branches follow the drawings
- Duct insulation is provided in unheated spaces (e.g. attic, voids), in line with the Part F 2019 Installation and Commissioning Guide and Part L energy efficiency principles
- All joints are mechanically fixed and sealed to minimise leakage
- Condensate drainage for MVHR and wet ducts is correctly installed
- Filters, access panels and labels are accessible and correctly fitted
Any non-compliances are recorded and highlighted before testing proceeds.
4. Initial System Start-Up
We then:
- Power up the system and check for abnormal noise or vibration
- Confirm that fans run in the correct direction and at the expected speeds
- Verify that all sensors (humidity, CO₂, PIR, timers) and boost switches or boost triggers operate correctly and return to trickle as intended
This ensures that the control logic works before we start balancing.
5. Airflow Measurement & Balancing
With the property in the agreed test condition, we:
- Measure airflow at every supply and extract terminal using appropriate methods (typically a powered flow hood for unconditional measurements, as recommended in the NSAI scheme)
- Record both continuous (trickle) and boost rates, where applicable
- Adjust terminal settings and, if necessary, in-line dampers or unit fan speeds to bring each room in line with the design airflow
We always consider both:
- Individual room requirements (e.g. minimum extract rates from wet rooms per TGD Part F tables)
- Total system balance, so supply and extract volumes match appropriately in MVHR systems
6. System Functional Test
Once airflow rates are within tolerance, we carry out a complete functional test:
- Check that all control modes (normal, boost, holiday, standby, night-setback, etc.) work as intended
- Confirm that labelling is clear and understandable for the end user
- Verify that automatic controls (e.g. humidity or CO₂-based boost) respond and reset correctly
This step ensures the installation is intuitive and user-friendly, which is essential for long-term performance and indoor air quality.
7. Independent Third-Party Validation (If Required)
Where validation is required (new dwellings, BCAR projects, SEAI-funded deep retrofit, etc.), we:
- Coordinate with an NSAI-registered Ventilation Validator under the NSAI Ventilation Validation Registration Scheme
- Provide the validator with design documents, our commissioning results and calibration certificates
- Support any additional checks or repeat measurements requested by the validator
After successful validation, the validator issues an NSAI Ventilation Validation Certificate confirming that, at the time of inspection, the installed system met the minimum ventilation rates and design intent of TGD Part F (2019).
8. Client Handover & Documentation
At completion you receive a comprehensive handover pack which typically includes:
- Detailed commissioning and airflow test sheets (design vs measured L/s at every terminal)
- Signed commissioning and functional test checklists
- Calibration certificates for the instruments used
- O&M manuals and manufacturer datasheets
- A clear user guide explaining system operation, filter changes and routine maintenance
Where an NSAI validator is engaged, you also receive a separate Ventilation Validation Certificate issued by the independent third party.
What’s in Your Commissioning Report
Every ventilation system we commission comes with a written commissioning report. It records how the system was designed for your home, how the unit was set up, and what we measured in every room. The report follows TGD Part F 2019 and the government guide Achieving Compliance with Part F, and gives your BER assessor and the independent validator the information they need.
Your home and the installation
- Address, Eircode and MPRN (the electricity meter number used on your BER)
- Who installed the system and who commissioned it. We also commission and balance systems fitted by other contractors, and the report states this clearly.
- Date of commissioning and the technician who carried it out
Your ventilation unit
- System type as defined in TGD F: mechanical ventilation with heat recovery (MVHR) or continuous mechanical extract ventilation
- Manufacturer, model, serial number, firmware and where the unit is installed
- Heat exchanger type (heat recovery units)
The design for your home (TGD F 2019)
- Whole-house ventilation rate, worked out both ways TGD F requires: by occupancy (from the number of bedrooms) and by floor area, with the higher figure used
- Minimum boost rates for the kitchen, utility room, bathrooms and WCs, and the minimum capacity your unit needs
- Whether a boost facility is required
- Design airflow for every room
- Your home’s wet-room configuration (“Kitchen + n”), as used in DEAP for your BER
Fan power and heat recovery
- The declared specific fan power (SFP) and heat recovery efficiency of your unit for your home’s configuration, from the SAP product database (PCDB) that DEAP uses
- Specific fan power measured on site: the unit’s power at its normal setting divided by the measured airflow
- Both checked against the TGD Part L 2019 limits: SFP of 1.2 W/(l/s) or less for heat recovery systems, 0.6 W/(l/s) or less for extract-only systems, and heat recovery of at least 70 %
Fan settings
- Normal and boost fan speeds set on the unit, for supply and extract
Airflow measured in every room
- Every extract and supply valve measured at the normal and the boost rate
- Design and measured airflow side by side, each with a pass or fail: within ±10 % of design, or ±1 l/s for small flows of 10 l/s and below
- Totals for the whole house
Supply and extract balance (heat recovery systems)
- Total supply against total extract at normal and boost rates. Supply must be at least equal to extract and no more than 15 % above it (TGD F 1.2.3.3).
Instruments used
- Make, model and serial number of each measuring instrument, with its calibration date, expiry and certificate number
System checks (Yes / No / N/A)
- Doors and windows closed during the test
- Airflow direction correct at every valve
- No abnormal noise, vibration or smell
- Ducts in unheated spaces insulated
- Condensate drain trapped and connected (heat recovery units)
- Background vents of at least 2,500 mm² in habitable rooms (extract-only systems)
- 10 mm door undercuts
- Access for filter changes and maintenance
- Controls set to the manufacturer’s instructions
- Valves and grilles locked in position
- Operating and maintenance manual and handover given
Declaration and signatures
- The technician’s declaration that the system has been commissioned and balanced to the design
- Qualification and registration number, date of commissioning and signature, with room for your signature
- Notes on anything found on the day
- A note that validation (Part 4 of the Part F commissioning form) is carried out separately by an independent validator
Our technician’s certifications
- Copies of our technician’s ventilation certifications are attached to every report
Important Disclaimer
If Eco Vent did not design and install the original ventilation system, we cannot accept responsibility for validation failure caused by design or installation deficiencies.
Where test results or visual checks reveal non-compliance (e.g. undersized ductwork, missing insulation, poor routing, inaccessible terminals, or an incorrect system type for the airtightness level), the original designer or installer must rectify these issues before validation can be completed.
Eco Vent will give you the measured readings and, once the corrections have been carried out, come back to retest and balance the system.
Can every system be balanced?
No. About half of the systems fitted by other installers that we’re asked to balance can’t be set up as they are.
Balancing only fine-tunes a system that was built right. If a room has no duct, a pipe is connected to the wrong side, there are too few pipes for a room, or the runs are too long and full of bends, the air simply can’t get where it should. Turning the fan up doesn’t help. It just makes the house noisy and costly to run.
If yours can’t be balanced
You pay €200 for the attempt instead of the full price, plus the usual travel charge beyond 100 km. That covers the time we spend measuring and trying to set it up, about an hour. You get the readings: which rooms fall short and by how much. If it can be balanced after all, we do it on the same visit and the €200 counts towards the commissioning price.
Once the pipes are built in, nobody can see where the fault is. Your installer knows how the pipes run and has to find it. When it’s fixed, we come back and balance it.
Is there a design?
When you book, just tell us whether your system was designed. Are there airflow calculations, and a drawing that shows the valves in each room, how many plenum boxes there are and how many pipes go to each one? A yes or no is enough. Without a design, nobody knows what the airflow in each room should be, and balancing is guesswork.
Why Choose Eco Vent for Ventilation Test?
Eco Vent combines on-site experience with a strong focus on Irish regulations and standards:
- We work directly to TGD Part F (2019) for ventilation design, installation and commissioning
- We apply the principles of S.R. 54:2014 / A2:2022 for retrofit projects, where ventilation, airtightness and moisture control are closely linked
- We follow TGD Part L (2022) requirements for airtightness testing, mechanical ventilation performance and commissioning of building services
- Our procedures align with the NSAI Ventilation Validation Registration Scheme and I.S. EN 14134:2019 performance testing methods
Homeowners, architects and contractors across Ireland choose Eco Vent for:
- Accurate, fully traceable airflow test reports
- Quiet, energy-efficient, balanced systems
- Professional support with BCAR, BER and NSAI validation documentation
Ventilation Test Compliance Standards
Part F 2019 Requirements & Future Updates
TGD Part F (Ventilation) 2019 significantly strengthened the requirements for:
- Documented system design (including general and boost ventilation rates)
- Proper installation and airtight, insulated ductwork
- Commissioning, airflow measurement and record-keeping
- Independent validation of mechanical systems through recognised schemes
Key practical requirements include:
- Ductwork in unheated spaces should be insulated to reduce heat loss and condensation risk, typically with at least 25 mm of insulation (λ ≤ 0.04 W/mK), in line with Part F guidance and the broader energy efficiency principles of Part L.
- All duct joints should be sealed and mechanically secured to limit leakage and noise and to ensure measured airflow reflects design intent.
- Installers and designers must provide full documentation and clear user guidance at handover, allowing the homeowner to operate and maintain the system correctly.
The Code of Practice for Inspecting and Certifying Buildings and Works (BCAR) requires that Assigned Certifiers retain relevant ancillary certificates, including ventilation commissioning reports and (where applicable) Ventilation Validation Certificates, for at least six years as part of their statutory records.
SEAI-funded major renovation projects must comply with the Domestic Technical Standards and Specifications (DTSS), which in turn refer back to TGD Part F, Part L and the NSAI Ventilation Validation Scheme for mechanical ventilation in airtight dwellings. In practice, this means that any SEAI-supported deep retrofit relying on mechanical ventilation is expected to have:
- A properly designed and commissioned system, and
- A Ventilation Validation Certificate issued by an NSAI-registered validator, where required by the scheme.
From our commissioning visits
Typical Costs and Inclusions
The cost of an airflow test and commissioning visit depends on:
- Total dwelling size and number of terminals
- System type (MVHR, MEV, DCV, PSV, intermittent extract)
- Location, site access and travel
- Whether NSAI third-party validation is required on top of commissioning
Every Eco Vent airflow testing and balancing service includes:
- Full airflow testing of all supply and extract terminals
- System balancing at trickle and, where relevant, at boost
- A commissioning report comparing measured and design flows
- A compliance summary and professional recommendations
Where NSAI validation is required, additional fees for the independent validator apply.
Ventilation Compliance Standards: Part F 2019 Requirements and 2025 Draft Updates
Part F (Ventilation) 2019 — and the upcoming 2025 updates — strengthen the requirement for certified testing. These regulations clearly highlight the need for proven system performance and proper documentation.
Specifically, installers must insulate all ducts in unheated spaces with a minimum 25 mm layer (thermal conductivity ≤ 0.04 W/mK). Moreover, they seal every duct joint to ensure airtightness and verify airflow results in line with I.S. EN 14134:2019.
Additionally, contractors provide full documentation and deliver clear user guidance before handover. As a result, homeowners receive a transparent record of how their ventilation system performs.
Under the Code of Practice for Inspecting and Certifying Buildings and Works (2016), Assigned Certifiers retain both the Ventilation Validation Certificates and commissioning records as part of BCAR ancillary certificates for at least six years.
Furthermore, SEAI-funded major renovation projects must meet DTSS standards to maintain balanced ventilation in airtight dwellings. Every major renovation project requiring mechanical ventilation must include a Ventilation Validation Certificate
Frequently Asked Questions About Ventilation Commissioning
Do I need an airflow test for Part F compliance?
Yes—if your dwelling relies on a mechanical ventilation system (MVHR/HRV, MEV, DCV, PSV or intermittent extract fans with background ventilators), TGD Part F (2019) requires that the system is designed, installed, commissioned, and its airflow rates measured and recorded by a competent person.
What is MVHR/HRV balancing?
Balancing is the process of adjusting an MVHR/HRV system so that:
- Each habitable room receives the correct supply airflow
- Each wet room provides the correct extract airflow
- Total supply and extract are in appropriate balance
This ensures effective heat recovery, stable pressures and consistent indoor air quality throughout the dwelling.
Do you test MEV and DCV systems?
Yes. We commission and balance:
- Centralised and decentralised MEV systems
- Demand-controlled ventilation (DCV) systems, where correct sensor setup and minimum airflow rates are critical
- Other hybrid solutions in line with TGD Part F and the NSAI Validation Scheme
What documents will I receive?
You receive:
- A detailed ventilation commissioning report (flows in L/s per terminal, trickle and boost where relevant)
- Signed commissioning and functional test checklists
- Instrument calibration certificates
- A tailored Owner’s Handover Pack explaining everyday operation, routine maintenance and basic troubleshooting
If an NSAI-registered validator is engaged and the system passes validation, you also receive a separate NSAI Ventilation Validation Certificate issued by that independent third party.
Can I adjust my ventilation system after it has been commissioned?
You should not change fan speeds, damper positions or controller settings after commissioning without professional advice. Any adjustments can:
- Unbalance the system
- Reduce indoor air quality in specific rooms
- Undermine the assumptions used for BER, BCAR and NSAI validation
If changes are needed (e.g. after alterations or extensions), the system should be re-checked, re-balanced and, where applicable, re-validated.
What is the most common reason for not receiving ventilation system validation?
The issues we see most often include:
- Design errors (e.g. incorrect system type for the airtightness level, undersized ductwork, or insufficient general ventilation rate)
- Installation issues (crushed ducts, excessive bends, missing insulation, leaky joints)
- Measured room airflows that fall below the design values, particularly in upstairs bedrooms or long duct runs
- Occupants or other trades changing damper positions, fan speeds or controls before validation takes place
Eco Vent measures the system and gives you the readings. The corrections are for the original installer; once they are done, we retest and balance the system.
Book Your Ventilation Test Today
If you need a professional airflow test or HRV balancing in Dublin, Leinster, or anywhere in Ireland, Eco Vent can help. Our engineers deliver precise measurements, verified calibration, and full compliance with Irish Building Regulations.
To ensure your system runs efficiently and meets every standard: