installing plastic pipe central heating in bungalow

[wgm50]

just bought a bungalow which as 11 rads which i plan to replace and reinstall them with plastic pipe in the brick walls etc the property is 19 meters long and 7 meters wide the boiler is situated in the middle of the property and the boiler is a greenstar 28i junior 2014 model. question is i found the 22mm return and feed pipes in loft what size plastic pipe would you recommend for the main feeds and return pipes and would it be ok to run 10mm pipe off the main 22m feed and return to the rads not forget the pipes will go into the brick wall

Thank you

 

[OffshoreGas]

just bought a bungalow which as 11 rads which i plan to replace and reinstall them with plastic pipe in the brick walls etc the property is 19 meters long and 7 meters wide the boiler is situated in the middle of the property and the boiler is a greenstar 28i junior 2014 model. question is i found the 22mm return and feed pipes in loft what size plastic pipe would you recommend for the main feeds and return pipes and would it be ok to run 10mm pipe off the main 22m feed and return to the rads not forget the pipes will go into the brick wall

Thank you

To size pipe work correctly you’d need an idea of room sizes, window sizes etc. You can find tools online to work out how much heat you need. You can use that to work out him much flow you need.

Personally I’d never bury any pipe in a wall as it wastes a lot of heat/energy. Burying plastic is also likely to result in premature failure due to expansion/contraction.

 

[Aire]

Some don't like micro bore pipes and some done like burying pipes in the wall either. Fact is though, if it's done properly you'll be fine and it's perfectly acceptable. Taking 10mm feeds to each radiator off the main 22mm flow and returns is fine and when putting pipes in the wall cover them with felt sleaving, this helps give the pipe room for expansion and also protects against abrasion.
[automerge]1570223615[/automerge]

To size pipe work correctly you’d need an idea of room sizes, window sizes etc. You can find tools online to work out how much heat you need. You can use that to work out him much flow you need.

Personally I’d never bury any pipe in a wall as it wastes a lot of heat/energy. Burying plastic is also likely to result in premature failure due to expansion/contraction.

What's room size got to do with pipe size? And if burying plastic pipe causes premature failure why is that underfloor heating companies offer upto 50 year warranties?

 

[ShaunCorbs]

Depends on the length wouldn’t run 10mm more than 3m away from the 22mm

 

[OffshoreGas]

@Craig Watson, the size and construction of a room dictate how much heat input you need to heat a room. Radiators transfer heat from the hot heating water to the cool room. The more heat you need to put into the room the greater the flow rate you need of hot water.

Pipes are sized based on the speed that the liquid travels down them, if that liquid travels too fast you get lots of noise, cavitation, pressure loss and erosion. The speed the liquid travels at is proportional to the size of the pipe (to get the same flow down a smaller pipe the liquid has to go faster). Bigger pipes cost more money so it’s a balance to try and find the smallest pipe that gives you the flow/pressure drop/velocity that meets your requirements.

I don't like chasing pipes into walls because a lot of heat is wasted in warning the rather than the room.

Fair point on UFH pipes, they are normally installed on top of PU foam insulation boards so free to expand on one direction at lowest unlike a pipe encased in bonding/plaster.

 

[Best]

10mm won’t cope with any great length of run, so best just bare minimum distance (just down wall).
Remember distance is X 2 flow and return.
You could run pipes inside a pipe sleeve.
Personally I wouldn’t use plastic pipes on a heating system, or push fit.
Plastic pipes apparently all absorb air

 

[king of pipes]

Just about every new build has plastic pipework installed providing it's installed correctly it will work, is it as good a traditional copper system then no in my opinion but sometimes you have to complete with other installers so have to be in and out as quickly as possible, always use a barrier pipe and keep 10mm radiator runs short as practically possible these should be protected and traceable download hep 20 installation information it will give you some idea . Kop

 

[Deleted member 32524]

Just as easy to run 15 plastic. I would go 22 main carcass 15 rad feeds.

 

[wgm50]

thank you everyone for your reply's and professional advice. i have one last question if i was to put 10 mm pipe from the 22 mm feed what would be the maximum length of the 10 mm i could use

 

[ShaunCorbs]

3m per leg no longer than that