Unventilated Air Layers with a Reflective Coating in the Building Envelope

2018 ◽  
Vol 931 ◽  
pp. 496-501 ◽  
Author(s):  
Nina P. Umnyakova ◽  
Adam Ujma
Keyword(s):  
Heat Exchange ◽  
Thermal Insulation ◽  
Building Envelope ◽  
Radiative Heat Exchange ◽  
Aluminium Foil ◽  
Reflective Coating ◽  
Air Layers ◽  
Design Calculations ◽  
Reflective Coatings

Heat exchange through infrared radiation in air layers located inside building envelopes may be significantly modified in case of use of aluminium foil coatings therein. The intensity of conductive, convective and radiative heat exchange in these structures depends on the thickness of the air layer and the temperature difference on its surfaces. Generally speaking, application of aluminium foil in air layers of a building envelope improves its thermal insulation capacity. However, assessment of efficiency of such a solution and determination of the thermal resistance value of a given structure is often incorrectly determined and assumed for design calculations. The article analyzes the instructions and principles of determination of thermal insulation capacity of unventilated air layers. Provisions of two standards have been compared with results of tests of air layer parameters. The effect of different factors on heat exchange and insulation capacity of air layers with reflective coatings has been considered and assessed.

scholarly journals The determination of the thermal reliability criterion for building envelope structures

2019 ◽  
Vol 13 (2) ◽  
pp. 129-133
Author(s):  
Gennadiy Farenyuk
Keyword(s):  
Thermal Insulation ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Time Analysis ◽  
Thermal Reliability ◽  
Thermal Failure ◽  
Reliability Criterion ◽  
Building Operation

The paper presents the basic methodical principles for the time analysis of the variations of envelope structures’ thermal insulation properties and for the substantiation of the thermal reliability criterion, which should allow the analysis of the actual parameters of heat losses during the operation of buildings. In the paper, the state of the envelope structures thermal failure, the concept of building thermal envelope thermal reliability and the principles of its rating are defined. The physical meaning and basic criterion of the envelope structure thermal reliability are formulated. The application of the thermal reliability criterion allows determining the probable variations in the thermal insulation properties during the building operation and, accordingly, the changes of the building energy performance over time.

scholarly journals Thermal efficiency of the building envelope with the air layer and reflective coatings

2019 ◽  
Vol 100 ◽  
pp. 00082
Author(s):  
Adam Ujma ◽  
Nina Umnyakova
Keyword(s):  
Thermal Protection ◽  
Heat Insulation ◽  
Building Envelope ◽  
Air Gap ◽  
Air Gaps ◽  
Number Of Factors ◽  
Air Layers ◽  
The Difference ◽  
Heat Shielding ◽  
Reflective Coatings

Currently, when calculating the heat-shielding qualities of external enclosing structures, the ability of fencing surfaces to reflect the heat flux by radiation is not taken into account. All this leads to an underestimation of heat-shielding characteristics in comparison with reality. Studies have shown. that a number of factors affect the thermal protection of air layers - the difference in temperature on the surfaces of the interlayer, its thickness. But the most important is the coefficient of elimination of the air gap surface. The use of reflective heat insulation with a low emissivity on one of the surfaces of the air gap makes it possible to increase its thermal protection 2.5–3 times. The article presents the calculations of thermal protection of air gaps with different emissivity coefficients of surfaces and conclusions about the effectiveness of the use of reflective insulation.

Analysis on the Energy-Saving Property of Solar Heat Reflective Coatings on Building in Beijing

2014 ◽  
Vol 787 ◽  
pp. 159-163 ◽  
Author(s):  
Qian Jin Mao ◽  
Qiu Rui Lv ◽  
Ya Li Wang ◽  
Xiao Yu Ma ◽  
Rui Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Building Envelope ◽  
Heat Gain ◽  
Reflective Coating ◽  
South Wall ◽  
The Common ◽  
North Wall ◽  
Saving Effect ◽  
Reflective Coatings

To discuss the effect of energy saving of heat-reflective coating on building, the heat gain of exterior building envelope in summer and winter in Beijing has been calculated. The results indicated that the higher the reflectivity of coating, the better the energy saving effect. The energy consumption of roof and different direction walls were analyzed. The energy saving effect on roof is the best, however the effect is not obvious on the east and west walls. The heat reflective coating has no effect on north wall but exhibits effect on south wall. The energy saving effect of brick red heat-reflective coating is not obvious compared with the common brick red coating.

Sign in / Sign up

Export Citation Format

Share Document