Best pipe insulation and where do I need it?

[MikeSharp01]

It's time to insulate water pipes and I am looking for the best options given the vast array of products out there and where to insulate, we have several water mediums to consider, some like anything to do with hot water - including UFH, are obvious but the cold water supplies not so obvious. Should I, for instance, routinely insulate mains / softened potable cold water to taps, basins, cisterns etc? The house is very well insulated and air tight.

[Nickfromwales]

The black neoprene and cheap grey EPS stuff are near identical in thermal performance, which I was surprised by, so I now install EPS internally with wall thicknesses to suit the application.

 

I seldom insulate the cold pipes tbh, as plastic pushfit (Hep) pipe seems to be a world away from copper in terms of condensation risk.

 

Plant rooms need everything insulating imo as the temp differences there are the most adverse, so defo the cold mains supply to manifolds but only in a 9mm or 13mm wall product. 
 

Insulating the hot pipes where there is no hot return (in such a dwelling) seems pointless too tbh, so I just put hot & HRC together in the same insulation to wrap them up nice and toasty (25mm wall) and then call it a day after that.

 

Very different advice would be stated if this was a typical uk home with pipes under voids / in cold attics etc obvs. 

[Nickfromwales]

UV resistant neoprene for outdoors stuff, to an ASHP for eg, but also the neoprene doesn’t get munched on by rodents for some reason whereas EPS outside is a buffet! 

[Iceverge]

44 minutes ago, MikeSharp01 said:

It's time to insulate water pipes and I am looking for the best options given the vast array of products out there and where to insulate, we have several water mediums to consider, some like anything to do with hot water - including UFH, are obvious but the cold water supplies not so obvious. Should I, for instance, routinely insulate mains / softened potable cold water to taps, basins, cisterns etc? The house is very well insulated and air tight.

 

It's 's a waste of effort insulating any pipe that is only occasionally heated up like pipe runs to basins etc in my opinion. 

 

Anything that's permanently hot like a hot return loop or pipes attached to a cylinder need to be well insulated.

 

As for cold, it depends, if you are showing no evidence of condensation on them I wouldn't bother.

[saveasteading]

Polyethylene, which I think the cheap ones are,  gets munched, and I think shrinks and stiffens over the years.

But it's much cheaper.

I don't know what the difference is between what is called "economy" and " bylaw quality".

[nod]

58 minutes ago, MikeSharp01 said:

It's time to insulate water pipes and I am looking for the best options given the vast array of products out there and where to insulate, we have several water mediums to consider, some like anything to do with hot water - including UFH, are obvious but the cold water supplies not so obvious. Should I, for instance, routinely insulate mains / softened potable cold water to taps, basins, cisterns etc? The house is very well insulated and air tight.

Sort of wish I’d used these 

[saveasteading]

5 minutes ago, nod said:

wish I’d used these

What are "these"?

[nod]

2 hours ago, saveasteading said:

What are "these"?

Pipes that come with the insulation on 

Every pipe in the house is ready insulated Saves time 

[Nickfromwales]

2 hours ago, nod said:

Pipes that come with the insulation on 

Every pipe in the house is ready insulated Saves time 

Same we do with the MVHR ducts where we heat / cool (temper) the airflow to rooms.

 

TBH I don't insulate everything any more, so putting insulation on where needed afterwards seems the most cost-effective.

 

I work out the lengths of the hot & HRC run, walk it out, insulate in and tape it up well, and them pull it in in one go; we use band or 50mm waste pipe clips around the insulation to fix it into place vs clipping the pipes and then having to stop/start the insulation.

[Iceverge]

The physics doesn't work out for insulating pipes in a radial or trunk and branch setup. 

 

The insulation doesn't stop the transfer of heat, merely slows it. There is simply too little water in the pipes, too much surface area and too little depth of insulation to meaningfully retain any hot water in the pipes between uses in a house. 

 

In other words it will cool to room temperature whether you insulate it or not between average tap usage intervals. Your time is far better spent on minimising the volume of water in your dead leg by short runs and thin pipes etc.

 

There is a difference where the pipe is always hot like a HRC ( a symptom of bad house design in my opinion) which should be massively insulated or pipes coming from an UVC. These continuously loose heat as it is internally replenished. 

 

Another thing to consider is heat loss through convection. Any pipes rising vertically from a permanent source of heat will be prone to this. It may be desirable in the case of a preheated hot water manifold ( I did this ) but usually it's not ( I accidentally did this for my control block for the UVC).

 

 

[Nickfromwales]

10 minutes ago, Iceverge said:

a symptom of bad house design in my opinion

...or practical necessity in anything bigger than a flat.

 

On a project we just fired up such a system, and the kitchen sink is appx 5m from the UVC. As the taps are modern EU regulated offerings there is a 9 second delay to get premium hot water to that outlet (15mm). In normal occupation the HRC will keep a fair amount of the primary hot pipework warm / hot throughout the day, so I will assume this will reduce to maybe 4-5 secs, but if not this may end up getting added to the HRC.

 

For the small running cost per annum (likely entirely offset if you have PV) it is a great thing to open a tap and the hot water is available instantly, particularly for low volume / high frequency outlets such as a hand wash after using the loo or rinsing something at the kitchen sink.

 

I do like the option for the Quooker hot (as well as boiling) water doo-dah at the kitchen sink, if that meant you could otherwise do away with a HRC, but it's always down to the individual case / client and distances from UVC > outlet. We always discuss this very comprehensively before getting the tools out, so expectations are managed and nobody can whinge afterwards (if the water is slow to arrive at these modern, low-flow rate taps etc, for eg).

[marshian]

6 hours ago, Nickfromwales said:

Very different advice would be stated if this was a typical uk home with pipes under voids / in cold attics etc obvs. 

 

Indeed

 

I have

 

Copper pipes under a suspended ground floor and running in a very well ventilated void - these are all insulated (CW, HW and CH Flow and Return)

 

Copper pipes above an insulated cold loft that is ventilated - these are all insulated (CW Tank Feed, HW F&E

 

The only pipes between loft and floor that are insulated are the flow and return to the HW Tank from the boiler and All pipework in the airing cupboard

 

All HW, CW and CH flow and returns inside the heated envelope are not lagged mainly because they are boxed in or under the first floor - I did consider it