Abstract
Results from a preliminary study on heat losses from air ducts are presented in this report. A duct system was installed on top of the joisting of an attic and the temperature in the space below the attic was controlled to approximately +20 deg C. The duct temperature was controlled to constant values of +20, +30, +40 and +50 deg C respectively both for the uninsulated duct and for insulation with low and high density loose-fill materials. With each type of loose-fill material measurements were carried out for two insulation levels (0.5 m and 0.6 m) and the specific duct-loss factor F{sub k} was calculated. A simplified analytical model was developed in order to deal with the results in a systematic manner. This model gives the heat loss as the product of a material factor (the thermal conductivity), a geometrical factor concerning the position of the duct (with all dimensions given in equivalent duct diameters) and the temperature differences between the duct wall and the top and bottom sides of the insulation respectively. Reasonable agreement was obtained for ``thick`` insulation between measured and calculated values for the total loss although losses to the top side tend to be underestimated and
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Citation Formats
Fahlen, P.
Heat losses from air ducts; Vaermefoerluster fraan luftkanaler.
Sweden: N. p.,
1992.
Web.
Fahlen, P.
Heat losses from air ducts; Vaermefoerluster fraan luftkanaler.
Sweden.
Fahlen, P.
1992.
"Heat losses from air ducts; Vaermefoerluster fraan luftkanaler."
Sweden.
@misc{etde_10121010,
title = {Heat losses from air ducts; Vaermefoerluster fraan luftkanaler}
author = {Fahlen, P}
abstractNote = {Results from a preliminary study on heat losses from air ducts are presented in this report. A duct system was installed on top of the joisting of an attic and the temperature in the space below the attic was controlled to approximately +20 deg C. The duct temperature was controlled to constant values of +20, +30, +40 and +50 deg C respectively both for the uninsulated duct and for insulation with low and high density loose-fill materials. With each type of loose-fill material measurements were carried out for two insulation levels (0.5 m and 0.6 m) and the specific duct-loss factor F{sub k} was calculated. A simplified analytical model was developed in order to deal with the results in a systematic manner. This model gives the heat loss as the product of a material factor (the thermal conductivity), a geometrical factor concerning the position of the duct (with all dimensions given in equivalent duct diameters) and the temperature differences between the duct wall and the top and bottom sides of the insulation respectively. Reasonable agreement was obtained for ``thick`` insulation between measured and calculated values for the total loss although losses to the top side tend to be underestimated and losses to the bottom side tend to be overestimated. A combination of further measurements and computer calculations could much improve upon the model. (18 refs.).}
place = {Sweden}
year = {1992}
month = {Dec}
}
title = {Heat losses from air ducts; Vaermefoerluster fraan luftkanaler}
author = {Fahlen, P}
abstractNote = {Results from a preliminary study on heat losses from air ducts are presented in this report. A duct system was installed on top of the joisting of an attic and the temperature in the space below the attic was controlled to approximately +20 deg C. The duct temperature was controlled to constant values of +20, +30, +40 and +50 deg C respectively both for the uninsulated duct and for insulation with low and high density loose-fill materials. With each type of loose-fill material measurements were carried out for two insulation levels (0.5 m and 0.6 m) and the specific duct-loss factor F{sub k} was calculated. A simplified analytical model was developed in order to deal with the results in a systematic manner. This model gives the heat loss as the product of a material factor (the thermal conductivity), a geometrical factor concerning the position of the duct (with all dimensions given in equivalent duct diameters) and the temperature differences between the duct wall and the top and bottom sides of the insulation respectively. Reasonable agreement was obtained for ``thick`` insulation between measured and calculated values for the total loss although losses to the top side tend to be underestimated and losses to the bottom side tend to be overestimated. A combination of further measurements and computer calculations could much improve upon the model. (18 refs.).}
place = {Sweden}
year = {1992}
month = {Dec}
}