BS EN 14134:2019 pdf free.Ventilation for buildings – Performance measurement and checks for residential ventilation systems.
Checks and measurements conditions are as follows: the mechanical ventilation system shall be switched on;  the system settings shall remain unchanged during measurements; all external and internal doors, and windows shall be closed; all other ventilation provisions such as externally and internally mounted air transfer devices should be set in their intended position which shall be recorded in the report; as set points of control devices have an impact on the performances of the system, they shall be recorded in the report. in the case of occupancy control or demand control and as the value of the relevant parameters has an impact on the performances of the system, these parameters or any overriding of the controls should be recorded in the report.Checks and measurements for ventilation systems of the same type (example of types are natural ventilation, unidirectional ventilation or bidirectional ventilation) within apartments belonging to the same building or within houses belonging to the same housing estate can be performed on a sample of these apartments or houses. NOTE The basic assumption behind the authorization for sampling is that ventilation systems that belong to such groups (same type and same building or same housing estate) and that are considered together for the purpose of measurement and checks (for example because of same owner or same general contractor or same installer) have enough similarities to make sampling relevant. The sample size depends on the selected sampling level and the total number of apartments or houses of the considered group. Table 2 gives the sampling error for each sampling level for a level of confidence of 95 %. Table 3 gives the sample size as a function of the total number of apartments or houses for each sampling level. For total numbers of apartments or houses that are not in Table 3, the sample size is calculated using Formula.BS EN 14134 pdf download.