Using the U-Value Calculator

By Ashley Rice 

You can access the Cymap built in U-Value calculation tool either in a project under tools, U-Value Calculator, in the elements fabric details listing or in the Cymap menu under the minor programs list.

Once in you’ll see an apparantly blank screen pop up. It is best to maximise this screen and start by clicking File, New.

You will then be able to populate the gerneral details of the element you need to create. As you will eventually be able to roll this new element out to multiple projects, it is worth giving it a memorable title (keeping within the 16 charater limit).

Element type, Surface Resistances, Heat Flow, Roof Type and Condtions are all under the Element details listing.

Correction factors are applied to the U-Value based on the wall ties under fasteners per meter squared and the fasteners thermal conductivity as shown below:

Click OK and we then move on to building up the Element from the inside out.

Select your internal element i.e plaster type and the thickness of the plaster:

Select your next internal element and the thickness. Then if needed apply a bridging layer percentage:

Choosing mortar Inner leaf, tick the Bridging layer box and apply the percentage to your second element.

Again from the materials listing, choose the insulation element you wish to use and apply the thickness:

Last on the list will be the external element and again any briding layer percentage you wish to apply to it:

Click finish to be taken to the graph of your new element as shown below:

You can edit it afterwards by clicking edit, edit layer and clicking the crosshair on the element you wish to edit. Perhaps you want a better U-value or maybe there is intisistual condensation.

You can also add a layer and increase the insulation thickness as shown above.

Finally, click file, save as a .ELM file and then click file send element to the elements listing. You will then be able to see it in the elements listing and use it on any projects going forward.