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Ventilation Validation

Hession Energy are Galway based Ventilation Validators, and we carry out ventilation validation inspections nationwide. We are NSAI Certified assessors, and have carried out over 100 assessments in the last year alone.

Under Building Regulations Part F 2019, all new builds are required to have an independent ventilation validation test carried out to ensure that the installed system is appropriately sized, and that the airflow provided is sufficient for the dwelling. Ventilation systems must be designed and commissioned to provide adequate and effective means of ventilation to satisfy the minimum requirements of TGD Part F of the Irish Building Regulations. 

Every ventilation system is designed based on the size and layout of the specific dwelling they are being installed in, and the system is commissioned by the supplier/installer, who adjusts the speed of the systems fan, along with adjusting the input/output ports in each room, to provide the adequate levels of air flow for each room depending on size and intended use. The role of the Independent Ventilation Validator, is to obtain the commissioning documentation, visit the dwelling, and measure the air flow from all of the relevant ports to ensure that the values provided by the installer are an accurate reflection of the air volume traveling through the system. These values are specific to each house, and each house has a minimum requirement for individual and total air flow.

If a house has natural ventilation (trickle vents) then a test is not carried out however the passive vents are inspected and the total openings are calculated to see if adequate ventilation is being provided. It should be noted that with natural ventilation, the NSAI air tightness test result should be no worse than 5m^3/hr/m^2, however, importantly also cannot be less than 3m^3/hr/m^2. If the air tightness test is less than 3m^3/hr/m^2. then the house does not comply with Part F 2019 and will have to have some form of mechanical ventilation installed. 


To date we have been finding approximately 40% of houses we have tested are failing the ventilation validation assessment. The main reason for this in our opinion is the ventilation systems are not been commissioned correctly and the units are been adjusted after the commissioning is carried out. If a ventilation system is not working correctly, or not providing the minimum volume of air flow, this can result in excess moisture inside the dwelling, and effect the thermal comfort levels in a house. 

Before we go to site a Hession Energy engineer will review the ventilation commissioning report to see if the report was prepared correctly and the system is sized appropriately. During the on-site inspection, one of our ventilation validators will assess the property’s mechanical ventilation system. We will test the input/output ports using a flow hood to determine if the air flow specified by the installer is being achieved. Our ventilation validators can assess your system if it is a heat recovery, demand control ventilation (D.C.V), central extract ventilation or natural ventilation with mechanical extractor fans. 


Hession Energy provide ventilation validation tests in Galway, Limerick, Mayo, Roscommon, Sligo Westmeath, Dublin and nationwide.

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