Tracer gas techniques have become widely used to measure the ventilation rates in buildings. The basic principle involved is that of conservation of mass (of tracer gas) as expressed in the continuity equation; by monitoring the injection and concentration of the tracer, one can infer the exchange of air. Although there is only one continuity equation, there are many different experimental injection strategies and analytical approaches. These different techniques may result in different estimates of infiltration due to uncertainties and biases of the procedures.
The IEA Annex 18 Demand Controlled Ventilating Systems-(DCV-Systems) with 9 participants are just in the middle of the work. Reviews are indicating energy conservation possibilities in the range of 8-40% in experiments and even more in theoretical studies. Most of the case studies will start this autumn with sensor tests, test room studies, and trials in occupied spaces. In the testrooms will be simulated the conditions in dwellings ---and offices with various ventilating systems. Almost 30 occupied buildings will be involved in tests in dwellings, offices, auditoria, and schools.
Login