Online ETTV U-value calculator

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Online ETTV U-value calculator

Material
The sequence of material layers. Mateiral 1 is the outmost layer
Source
Library: standard materials defined in ETTV; User: materials input by user; Air gap: standard air gaps defined in ETTV
Name
Material name; editable for user materials only
Color
Material display color in the schematics; editable for user materials only
Thermal
conductivity
Material thermal conductivity in W/(m⋅K); editable for user materials only

[W/(m⋅K)]
Thickness
Material thickness in mm; editable for all materials, with 3 thickness options for air gaps

[mm]
Thermal
resistance
Calculated thermal resistance (R-value) of each material layer

[(m2K)/W]
Inside surface film resistance:
Thermal resistance of indoor air; automatically determined by wall/roof type and inside surface type
R-value
R-value is the overall surface-to-surface thermal resistance, with the outdoor and indoor air layers excluded
 =  (m2K)/W
U-value
U-value is the overall air-to-air thermal transmittance, with the outdoor and indoor air layers included
 =  W/(m2K)
©OTM Solutions Pte Ltd, V1.1.0, 26/06/2020

How to use the online U-value calculator?

The calculator is based on BCA ETTV code.

Get your wall/roof system U-value with a few simple steps:

  1. Specify the number of material layers: both solid and air layers;
  2. Select wall/roof type: vertical wall, horizontal roof or sloped roof;
  3. Input material properties: from ETTV material library, user-defined materials or standard ETTV air gaps
  4. Select inside surface type: low-emissivity for an inside surface covered with aluminum foil

The thermal resistance of each layer, overall system R-value and U-value are automatically calculated, according to the BCA ETTV code.

Looking for a professional U-value testing lab?

Please visit our thermal conductivity testing service page. Our lab is SAC-SINGLAS (ISO 17025) accredited and our customers are from more than 20 countries.

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Comments or feedback?

Please feel free to leave your comments or feedback to this online calculator in the “Leave a Reply” section at the bottom of this page. We will improve this online calculator regularly.

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