energy losses

The airtightness of a building envelope impacts upon the magnitude of uncontrolled air leakage and associated ventilation energy losses. A building's airtightness can be assessed using a steady state fan pressurisation technique. This paper describes a study on the largest building in the UK ever to have had its airtightness tested. Power law regression analysis revealed a good correlation between flow rate into the building and observed pressure differentials.

This report gives a comparison of the calculation methods used in 21 European countries for energy performance of buildings. It comments the differencies and similarities between these national procedures. Different aspects of calculation methods are analysed in details, including the way to calculate heat losses due to ventilation. Comments are given about the way by which calculations procedures are treating or taking into account points such as minimum ventilation rates, intermittent and demand controlled ventilation, air infiltrations, duct tightness, heat recovery, fan power.

A study of test methods for duct leakage revealed that there is room for improvement in this evolving field.

The development of new highly sensitive detection techniques for particle bound polycyclic aromatic compounds (PP AH) on the nano-particles of traffic born soot open a new dimension for real time measuring techniques for air exchange rates in buildings in operation. The principles and first measurements are presented and demonstrate the principal applicability of this method.

Describes how basic studies (detailed simulations) have been used to define the calculation of energy losses due to ventilation in French regulations, and the "ongoing" research aiming towards a better assessment of air quality.

The paper describes measurements made on large doors - 10 to 20 m2 in 2 buildings in Narvik. The air change was measured with the tracer gas (SFg). The method of constant concentration or decaying concentration of the tracer gas was used. The dosing, measuring and calculation of the air change was made with a Briiel & Kjaer gas analyser type 1302 and computer. Use of the decaying method was best with short opening times. The opening of the door in 5 to 7 minutes gives an air exchange of 500 m³ to 1300 m³ or an air change from 0.2 to 1.0.