Create target construction

[XYE]

Hi!

I'd like to ask about the Project constructions > Tools tab.

How do you specify/determine a value for the Target cM value?

Thanks,

Xye

[PCully]

Hi,

This is the SBEM Thermal Capacity, as far as I am aware it is only really used by UK Compliance regulations. It is based on the Construction density, thickness and specific heat capacity, more info can be obtained from the iSBEM user guides which you can download from the BRE NCM website http://www.ncm.bre.co.uk/.

Phil

[XYE]

Hi Phil,

Thanks for the reply. What I mean is, in the Create target construction tab, you can input the u-value that you want, say, 0.504 W/(m²-K), but how about the corresponding cM value? How do you determine this, or can you just accept the default value for it?

Thanks,

Xye

[PCully]

Hi,

Yes sorry was trying to get across that unless you will be doing UK Regs Compliance assessments (in which case the NCM site will give you all the info you need for this input) then you can just ignore and leave as default. I did a quick test simulation with different Cm values but the same U-value and results came out the same so I don't think it's something you need to worry over.

Phil

[XYE]

Hi Phil,

Alright then. Thanks very much.

Xye