The first step was to gather various documents that give information on the building. These are, if available, building design drawings and description, energy performance certificates (EPC), mandatory ventilation inspection (OVK) and energy bills.
In order to have more reliable input for the BES, the premises were visited by project personnel. Audits were carried out by inspection of the composition and condition of constructions and systems, power of building services and other electric components, set-points, and control settings.
Measurements made at site were:
• Temperature in zones and outdoor air.
• Temperature readings of installations, especially of supply temperature to radiators and domestic hot water circulation system (DHWC) inlet and outlet temperatures.
• In common spaces, lighting power and controls was assessed.
• Pictures were taken of the facades to ensure window and external wall areas.
At each site, an apartment was chosen to perform the following investigations/ measurements:
• Apartment room temperatures during the visit.
• Measurement of room and building dimensions.
• Assessment of window sizes and types.
• Estimation and prediction of material types and thicknesses in constructions (especially thermal insulation in walls).
• Readings of installation system gauges were made.
• Measurement of air flow rates in the ventilation terminals in the apartment (especially for the mechanically ventilated buildings).
• Blower door measurement for air tightness.
There were two types of longer term measurements:
• A temperature logger was left in the apartment to record the indoor temperature for at least 2 weeks and also one outdoors. This was to capture the long-term values more reliably.
• In apartments with natural ventilation, a tracer gas method was used to assess the overtime rate of air change; for at least 2 weeks.