Öppna spisar : metod som förhindrar öppna spisar att ryka in

Sammanfattning: The primary purpose of this thesis is to account for a new method of limiting the risk of smoke leaking out from the open fireplace into the room. The improved functionality is obtained by adding a turnplate to the open fireplace mounted horizontally inside the lower edge at the hood of the open fire. The streams of smoke and air, which are cold of the contact with the cool surfaces in the stove, have a tendency to fall down along the inside of the hood and continue out into the room. The stream is stopped and redirected back up into the chimney by the turnplate. The development of the method is based on measuring of temperatures and air flows in a monitored fireplace. Tests have been carried out partially in a test fireplace in full scale and partially in a model of the test fireplace at the scale 1:2. The model fireplace is made in glass which makes it possible to study and photograph the streams of smoke inside of the fireplace and oil fog has been used for the demonstration. Temperatures on surfaces and gases in the fireplace have been measured during different periods of time. These measurements have shown that the greatest risk for backwards floating air currents occurs directly after having lit the fire and during some hour after that. It is during this time the temperatures in the fireplace will rise. Measurements and also film-recordings have therefore been concentrated to these periods of time. The heat gain from the fire has been measured in connection to the tests. The distribution of the heat through radiation and convection based on the temperature measurements is shown.