Accurate measurement of the positions of windows, skylights, vents, dampers, etc. has always been a problem for researchers. Often open/closed switches are used which do not indicate the degree of opening which has occurred. The use of Hall-Effect sensors to measure such positions was first proposed for monitoring residential passive air inlets.
A new turbinemeter is developed to be used as a ventilating rate sensor in livestock buildings. Starting from a previous sensor, which we introduced in 1983, several improvements were done tobecome a low cost air flow rate sensor with an acceptable accuracy of 60 m3/h in a range from 200 to 5000 m3/h and this for pressure differences from 0 to 120 Pa. This sensor can beintegrated in the climate control equipment of livestock buildings to improve process control.
Good indoor air quality and thermal comfort and good energy-efficiency can be achieved simultaneously only if the amount of ventilation can be demand-controlled. Two approaches are discussed in the article: CO2- control and use of so-called air quality sensors. The first experiments have been promising but further development of equipment is still needed, in order to improve the reliability and economy of demand-controlled ventilation.