Insulating crawl space pipes and other questions!

[dabaldie]

i have a crawl space beneath my house which is well ventilated.
Most of the downstairs heating pipes run throught this space, just beneath the floorboards. (in a mix of copper and polypipe)
Is it well worth the saving to insulate the pipes?. bear in mind it will take me best part of a day in really cramped and cold conditions?

and if, , the front room radiator never seems to heat the room enough even when the TRV is up full, will it help heat the room by raising the temp of the rad? (i guess in theory .. yes.. cos less heat loss.. but in practice?). I cany put a bigger radiator cos the missus has put two huge leather sofas in there and now there is no free wall space, other that the 2mx750mm that already has a rad (newish double) under the bay window!

any ideas on how to better utilise the rad?.. is the foil stuff behind the rad on the wall worth the spend?
thansk.. sorry bout the millions of questions.

 

[chrishutt]

If you have a well ventilated ground floor with crawl space, you should definitely insulate underneath the whole floor! There are various materials you might use - polystyrene blocks that can wedge between the joist, mineral wall with paper backing that might be stapled under joists, etc. This would greatly reduce the heat loss through the floor (and draughts?).

 

[Agile]

And back to the original question, the CH pipework should always be insulated to prevent heat loss where it passes through unheated areas to to reduce the risk of freezing.

bearing in mind the advantage of insulating suspended wooden floors its surprising that there are no products on the market to specifically do that.

Wickes have a very expensive polystyrene sheet with precut zig zag slotts which can be quickly pushed into the space between joists or rafters without cutting as it fits 14-16 " spacing ( or similar ).

It may not be ideal but it may be a quick solution.

Fitting pipe insulation will only take about 1-2 hours, not all day!

Tony

 

[ChrisR]

I found it astonishing how much heat can be lost from pipes under ground floors. Pipe insulation is often not applied very well. It can be difficult at particular places, and most installers use 9mm, which is not up to the Standards. Thin pipes (15mm) lose more heat so need 25mm insulation.

Simplistically, if you're losing 2 degrees in the pipe going to a rad, and 2 coming back, and it has 11 degrees across it, you're spending 36% more on gas than you need. Wow?

 

[chrishutt]

Thin pipes (15mm) lose more heat so need 25mm insulation.

ChrisR! You didn't really mean that, did you?

Thicker pipes have a greater surface area and lose more heat. But when it comes to protection against freezing (which isn't the issue here) thinner pipes hold less heat and can therefore cool to freezing more quickly, hence the requirement for thicker insulation.