10 mm Pipe lagging and radiator fitting - local supplier

[Lusi83]

Hi
I'm after some pipe lagging insulation for 10mm CH pipes -have just insulated under my living room floor and now want to insulate the masses of CH pipes (resembles spaghetti - my installation really was done by cowboys!!!) under there....

Have seen the previous posts about buying it online -but I'd quite like to pick it up asap and also save on the postage charges...

What kind of plumbers merchant etc might sell it? Any names or ideas - so I could check locally...

Also have a leaky radiator (found whilst under floor...) tried to nip it up but hasn't worked (infact wiping off the dirt made it worse!) so might need to cut it off and redo - what are those fittings called that fix onto microbore to connect to the valve? And where can I get them?

 

[kirkgas]

Grahams, PTS, Plumb Centre are all in the Fife areas, try google search for something local to you

 

[Lusi83]

Thanks -but do you know if any of those supply 10mm pipe insulation...a couple of months ago I went round a few on a local industrial estate (grahams and plumb centre were ones I visited I think) and none had any....
and no-one could tell me were I could get some from....

 

[kevplumb]

try refregeration / air con suppliers

 

[bengasman]

I'd fix all the leaks first if I were you.

 

[Lusi83]

I'm trying to fix the leaks as well ...

problem I have is I lifted the laminate floor to get under the floor...with a young child and a cat using the underlay as a scratching post I need to get it back down asap...and I have 2 hours on Wed am when I can do either job...
I wouldn't have started insulating under the floor if I had known about the leaks before .... although I should have sourced the pipe lagging first ...but until I lifted the floor I didn't have a good enough idea of how much I needed - I already knew there was lots of extra microbore down there -sometimes I feel like I'm swimming in mud!!!!

 

[D_Hailsham]

10mm is approximately the "critical diameter". If the pipe size is less than the critical diameter, insulation is not recommended as the increase in the surface area exposed to the air is greater than the temperature drop through the insulation. So you get a greater heat loss with the insulation than without it.

 

[Lusi83]

It is actually 8mmm - does that mean that I shouldn't insulate it...and will I not get problems (freezing?) seeing as insulated under the floor boards above...

 

[Agile]

I would always insulate any heating pipe passing through an unheated area.

If this is a ground floor with the cavity under floor open to the outside then it should be insulated to prevent heat loss and discourage freezing.

Tony

 

[D_Hailsham]

It is actually 8mmm - does that mean that I shouldn't insulate it...and will I not get problems (freezing?) seeing as insulated under the floor boards above...

Let's put it this way, Knauf, who are probably the largest manufacturer of pipe insulation, do not make anything smaller than 15mm.

As for freezing, how long has the pipe work been there and what is below it. If it is just a void with the ground below, there is little chance of the pipes freezing. You could always install a frost stat under the floor which would turn the heating on if the temperature dropped below 5°C, but that would be belt and braces.

 

[kevplumb]

and look on the bright side your outgoing air bricks wont freeze

 

[bengasman]

...If the pipe size is less than the critical diameter, insulation is not recommended as the increase in the surface area exposed to the air is greater than the temperature drop through the insulation. So you get a greater heat loss with the insulation than without it.

The great theoretician forgets one thing: insulation has a much lower heat transfer than copper.
Following the above theory, thicker insulation would insulate less than thin insulation of the same material.
If A is greater than B, B is smaller than A; the smaller the surface area, the smaller the heatloss, so the thinner the insulation the less heatloss. I'll use gaffa tape from now on then.

 

[Agile]

Why would anyone want smaller heating insulation than 15 mm?

I just use 15 mm insulation on everything!

It is made in smaller sizes for the aircon trade buut its expensive.

Tony

 

[D_Hailsham]

...If the pipe size is less than the critical diameter, insulation is not recommended as the increase in the surface area exposed to the air is greater than the temperature drop through the insulation. So you get a greater heat loss with the insulation than without it.

The great theoretician forgets one thing: insulation has a much lower heat transfer than copper.
Following the above theory, thicker insulation would insulate less than thin insulation of the same material.
If A is greater than B, B is smaller than A; the smaller the surface area, the smaller the heatloss, so the thinner the insulation the less heatloss. I'll use gaffa tape from now on then.

Then I need to write to the authors of my school physics text book and tell them they are wrong. Oh dear, I think they must be dead. What a pity that thousands of students were misinformed.

Oh no. I have just found this on the net:

For a circular pipe with length very large compared to outer diameter, it may be assumed that the heat flows only in radial directions. If a layer of insulation is installed around the circular pipe to reduce the amount of heat transfer, then it is assumed that the heat transfer will be decreased by adding more insulation. By adding the insulation around the pipe the outside surface area is increased, which will increase the heat transfer.

So may be the authors got it right after all.

 

[Agile]

Suppose the insulation was totally perfect, or VERY good indeed like a vacuum flask?

The that would not be true!

Now another senario for you to consider! Get a fan and blow cold air at the pipe, OK? So it will cool quicker?

Well if you agree with that then encase the 10 mm pipe inside a tube of say 20 mm so the tube prevents draughts reaching the pipe! Surely that will lose less heat than the pipe in the open?

The text book you seem to have read must have been talking about a not very good insulation.

That green quote you have copied, why should that supposition be any different with a 100 mm tube compared with a 10 mm tube if it were true?

Tony