Changing internal pressure to achieve variable thermal conductivity in thermal insulation

• Cold climates might have a variable need for thermal insulation. When there are large heat loads a low Uvalueis preferable, and opposite when heat loads are low and it is cold outdoors. One way to adjust the Uvalueis to change the gas pressure within the insulation. This would be especially effective in nano-porousmaterials where the relation between pressure and thermal conductivity is stronger. Measurements have beenconducted on an aerogel blanket and a fumed silica material. The results show an almost linear dependencein thermal conductivity at pressures between 1 kPa and 100 kPA for both materials. In the measurements,the thermal conductivity increase by a factor between 1.5 and 2.6 (highest conductivity divided by lowestconductivity).

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Husbyggnad (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Building Technologies (hsv//eng)

Keyword

thermal conductivity

nano-porous insulation

thermal insulation

varied pressure insulation

Adaptive façade

Publication and Content Type

kon (subject category)

ref (subject category)