Complete new CH system - design questions

[SYDDOS]

My First Post.


I have spent 6 weeks researching all the new central heating systems including UFH, the components currently in use and Building regulations Part L and Part P (electrical).


The property is semi-detached, Gnd floor -large hallway, large kitchen-diner, huge extended lounge. 1st floor -3 Dbl Beds/Bathroom.


Room sizes, fabric heat loss, air changes etc have all been calculated. I intend to use a Gas Safe engineer for installation. Due to several other constraints, I’m leaning toward a system configured as follows.


Condensing system boiler located in loft.
CW tank - 227Ltr.
Fast re-heat HW Cylinder - 120Ltr
Plastic barrier pipe 15mm (External Diameter).
Two manifolds kits -Ground/First Flr.
Radiators on each floor directly linked to its corresponding flow/return manifold.


Have any of you installers DESIGNED and/or installed a similar configured system?

If you have, did you experience any problems with flow speed, heat delivery to the rads, temperature drop on the return circuit or any other problems?


I’m aware of the push-fit, vermin, o-ring, pipe sagging issues and opinions both for and against plastic pipe in CH systems.


[FONT=&quot]Syddos. [/FONT]

 

[GQuigley67]

is your boiler fed off of the tank or is it mains pressure ? I'm guessing its a gravity fed system.

if its fed off the tank then the boiler cannot be located in the loft as it will have to be below the cistern on the 1st or ground floor.

 

[Plumbstar Tom]

have you considdered unvented?

 

[SYDDOS]

is your boiler fed off of the tank or is it mains pressure ? I'm guessing its a gravity fed system.

if its fed off the tank then the boiler cannot be located in the loft as it will have to be below the cistern on the 1st or ground floor.

The HW cylinder is fed from the CW tank in loft.
System Type Boiler with expansion vessel to be located in loft.
System will be fully pumped.

 

[SYDDOS]

have you considdered unvented?

Yes, but I intended to install a power shower, hence the need for Large CW tank in loft. Using a system boiler does away with the Header tank.

 

[Plucky]

Yes, but I intended to install a power shower, hence the need for Large CW tank in loft. Using a system boiler does away with the Header tank.

Using an unvented cylinder will also do away with the need for any tanks in loft, providing you have sufficient mains pressure and flow rates.

I have sent you a private message

 

[HouseholderXX]

Just don't use JG Speedfit plastic pipe anywhere there is a possibility of mice let alone rats. Some people seem to think JG 'barrier' pipe means barrier to mice chewing...not so, it is vapour barrier, plastic foil I think. Our mice had our system depressurised withina few weeks thanks to use of plastic pipe underfloor. Keep to copper underfloor or in wall cavities and roofs, or run plastic inside the rooms where you can see the mice at work!
Wiser-now Householder.

 

[GQuigley67]

not everyone has mice in there house

 

[jambo]

unvented all the way

 

[gaspastemania]

ditch anything gravity , very 70's and annoying , unvented everytime for me

 

[SYDDOS]

Power shower on unvented system? How does that work?

 

[Gray0689]

Power shower on unvented system? How does that work?

Your shower will be mains pressure

 

[tamz]

Speak to a heating engineer (or 2) and get their advice and opinions on what may be best for you and your house.

Doing "research" on the internet is all very well if you know what to look for.
Unfortunately most don't and pick up a bit of this and that. Sometimes you need a bit professional guidance and as i can't see your set up i won't comment other than you can do better.

If i wanted to buy the wife bigger t..ts and researched all the options for weeks then popped along to the t..t clinic, i'm quite sure the surgeon would listen to what i wanted then steer me in the right direction to what was best.

I'm happy with what she has anyway

 

[HouseholderXX]

not everyone has mice in there house

Glad you know which houses they get into and which they don't! The pest control guys (council and commercial) say they get into pretty much every house at one time or another.

 

[HouseholderXX]

Vermin - if you think there might be mice don't use plastic pipe

The mice and vermin jokes are great but the reality is a defunct system until you rip up enough carpets and floorboards or wall cavities to find the chewed pipe. We were lucky - our plumber thought one of his joints had gone, so ripped up where he'd got most joints, and the mouse had obligingly done his tiny chew right there too. Pity our plumber didn't read the small print on the JG Speedfit website that says put plastic pipe in trunking if there might be vermin around - which there are in almost all houses at one time or another, so the pest control guys said later (council and a commercial firm).

Some people seem to think 'barrier' pipe means barrier to mice chewing and told me so...not so, I can now see, it's a vapour barrier, plastic foil I think. Our mice had our system depressurised within a few weeks thanks to use of plastic pipe underfloor. Keep to copper underfloor or in wall cavities and roofs, or run plastic inside the rooms where you can see the mice at work! We had copper for 25 years, and mice, and no trouble.
Wiser-now Householder (and expert mouse-catcher).

 

[Gray0689]

The mice and vermin jokes are great but the reality is a defunct system until you rip up enough carpets and floorboards or wall cavities to find the chewed pipe. We were lucky - our plumber thought one of his joints had gone, so ripped up where he'd got most joints, and the mouse had obligingly done his tiny chew right there too. Pity our plumber didn't read the small print on the JG Speedfit website that says put plastic pipe in trunking if there might be vermin around - which there are in almost all houses at one time or another, so the pest control guys said later (council and a commercial firm).

Some people seem to think 'barrier' pipe means barrier to mice chewing and told me so...not so, I can now see, it's a vapour barrier, plastic foil I think. Our mice had our system depressurised within a few weeks thanks to use of plastic pipe underfloor. Keep to copper underfloor or in wall cavities and roofs, or run plastic inside the rooms where you can see the mice at work! We had copper for 25 years, and mice, and no trouble.
Wiser-now Householder (and expert mouse-catcher).

I bet your house is lovely if you had mice for 25 years lol

 

[MR RIGSBY]

How many bathrooms/showers do you have? If theres only one then I would be lucking at a 40kw combi.

Would work out ALOT cheaper. Central heating side of things would be no problem and unless you had more than one shower hot water wouldn't be affected.

 

[HouseholderXX]

500 years of mice probably, that is the age of the house!

I bet your house is lovely if you had mice for 25 years lol

 

[doitmyself]

How many bathrooms/showers do you have? If there's only one then I would be looking at a 40kw combi.

Why 40kW? You don't know what the flow rate is!

 

[SYDDOS]

How many bathrooms/showers do you have? If theres only one then I would be lucking at a 40kw combi.

Would work out ALOT cheaper. Central heating side of things would be no problem and unless you had more than one shower hot water wouldn't be affected.

We may decide to install an en-suite next year and are considering a loft conversion or a two tier side extension (subject to planning permission), so any CH system will have to cope with the expected additional demand.

Combi boilers do require less materials, but are prone to pressure loss when more than one tap is opened and are not suitable for a true power shower.

 

[SYDDOS]

Re: Vermin - if you think there might be mice don't use plastic pipe

Some people seem to think 'barrier' pipe means barrier to mice chewing and told me so...not so, I can now see, it's a vapour barrier, plastic foil I think. Our mice had our system depressurised within a few weeks thanks to use of plastic pipe underfloor. Keep to copper underfloor or in wall cavities and roofs, or run plastic inside the rooms where you can see the mice at work! We had copper for 25 years, and mice, and no trouble.
Wiser-now Householder (and expert mouse-catcher).

I hear what you and others have said about plastic pipe. BTW some plastic barrier pipe employs aluminium inner tube as an additional barrier.

I must admit that I'm surprised that I cannot find any evidence of past or present vermin in this house, and given the state of the kitchen when I moved in, I would have expected vermin to have taken over. I know it doesn't mean they wont turn up one day.

 

[tamz]

Re: Vermin - if you think there might be mice don't use plastic pipe

I hear what you and others have said about plastic pipe. BTW some plastic barrier pipe employs aluminium inner tube as an additional barrier.

Unipipe. That won't stop them.

 

[GQuigley67]

nothing will stop those pesky vermin ! they are on a mission to sabotage plastic pipes they prefered the old copper ones.

 

[SYDDOS]

I've seen a few posts suggesting that plastic pipe when run under floors/in walls should placed in trunking, but I don't remember if any of the post said which type of trunking.... harden steel, granite rock, my old PE teachers socks?

 

[tamz]

It is just a risk they will chew them and like any other risk should be weighed up before you start. They can and do eat through plastic pipes (usually the fittings) but they are also fond of electric cables and there are not a lot of houses with armoured cable!

 

[Gray0689]

If there a problem with vermin put in the things that plug in to keep them away