how to assess thickness of Kooltherm FM Pipe Insulation needed?

[AjWill]

Good afternoon,

im looking at the Kooltherm FM Pipe Insulation but am not sure how to calculate what thickness I need for out central heating, I downloaded a PDF from their website but it made no sense to me, does anyone have an easy to follow guide for assessing the thickness needed?

The options are below



Thanks
Alex

 

[endecotp]

It is unusual to use Kooltherm for central heating pipes.

Why have you chosen it? What is your heat loss target?

 

[AjWill]

Oh, I see, I thought it was for central heating also. im about to put kingspan under my suspended floor and the current pipes are just wrapped in fibre glass wool, so I wanted to improve that to make sure I didn't have any issues with heat loss on the pipes or cold temps. I assumed the kooltherm was for that purpose?

 

[endecotp]

If the pipes are now going to be below the insulation then they should definitely be properly insulated. You can use that Kooltherm product if you want, but it is rigid so it will not be particularly easy to fit, especially at bends/joins in the pipes. It is more common to use a flexible pipe insulation, which is easy to fit and cheaper but also less insulating (for the same thickness). If you look at what places likes Wickes sell you’ll see that they often have two thicknesses, “economy” and “byelaw” i.e. the latter is thick enough to meet building / water regulations.

Re the Kooltherm FM, the PDF I’ve seen describes sizes that don’t seem to correspond with typical domestic copper pipe sizes, and the tables talk about steel pipes. This can be confusing because some pipe sizes are inner diameters and some are outer diameters. The people in “plumbing and central heating” might understand that better. But that PDF is pretty clear about what thickness you need in order to meet regulations. Of course adding more is always better, but it will get expensive pretty quickly.