Ventilation by demand.


Air-to-air heat exchangers for energy efficient ventilation of "tight" structures.

Reducing the air change rate of a house increases the concentration of pollutants in the indoor air. These pollutants are identified and located within the residential structure. Air-to-air heat exchangers are suggested tocontrol ventilation, and the three basic types described.

An investigation of operational factors that influence emission rates from gas appliances

Reports the result of investigation of the impact of various operational factors on trace combustion products emission rates from unvented gas appliances including ranges and space heaters. The impact of the following factors on the indoor NO, NO2 and CO emission rates were evaluated under controlled conditions in an environmental chamber - 1) the appliance typeand/or design, 2) the primary aeration level, 3) the fuel input rate, 4) the time dependence of emission rates, and 5) the presence of absorbing surfaces such as wood, plaster board, curtains, carpets, linoleum and plaster.

A fresh look at the building heat loss calculation.

Examines the fundamental building heat loss calculations. Points out some anomalies in the traditional view of room thermal behaviour. Treats equations governing room heat loss taking account of the temperature of the walls and the environmental temperature. Justifies the use of the environmental temperature rather then the air temperature. Examines the heat loss due to ventilation. Discusses the use of the temperature ratio.

Natural ventilation of rooms:a simplified analytical study. La ventilazione naturale degli ambienti studio analitico semplificato.

Presents an analytical procedure for evaluating the air change rate in a room due to the temperature difference between the interior and exterior, which occurs when a door or window is opened.

The use of tracer gas for determining ventilation efficiency.

The local ventilation efficiency of a mechanical ventilation system may in general terms be defined as "providing air in those parts of a room where it is required". In this paper different definitions of the local ventilation efficiency and methods for measuring it are discussed. Presents results from measurements of ventilation efficiency. A test room was mechanically ventilated and nitrous oxide used as a tracer gas. A number of sensors were placed in the room with the aim of determining the variations in the air change rates within the room.

Investigation of three computer programs for calculation of indoor climate.

Reports comparison of three computer programs designed to calculate room air temperature and heating loads. The programs are:< BRIS - a swedish program using a finite difference method< BYVOK - a norwegian program using the thermal response factor method