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] | |
|---|---|---|---|---|---|---|---|
Outside surface film resistance: Thermal resistance of outdoor air; automatically determined by wall/roof type | |||||||
| Inside surface film resistance: Thermal resistance of indoor air; automatically determined by wall/roof type and inside surface type | |||||||
R-value = (m2K)/W R-value is the overall surface-to-surface thermal resistance, with the outdoor and indoor air layers excluded | U-value = W/(m2K) U-value is the overall air-to-air thermal transmittance, with the outdoor and indoor air layers included |
©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:
- Specify the number of material layers: both solid and air layers;
- Select wall/roof type: vertical wall, horizontal roof or sloped roof;
- Input material properties: from ETTV material library, user-defined materials or standard ETTV air gaps
- 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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