central heating advice

[fizzy]

I want to install oil central heating in our offices.
I thought it would be a very simple job - but had a few plumbers around who seemed clueless. Too long a run one said. Too much pipe and you will need big bore as it's industrial etc etc.
Not much longer than the house I live in!

Excuse the rough drawing.

Red for rads and red for the boiler. It has to go on the back wall as the front is exposed to 90mph winds and sideways rain.

Looks to me like a very simple setup but I know nothing about plumbing!

Need 8kw in front office and say 4kw in the other 2. Then 2kw in the toilet area. Total of say 18 to 20kw of heat.

 

[angellonewolf]

@Kayos might be able to advice

 

[frank horton]

just run a simple 22mm bore loop to and from the boiler and take off the rad feeds as and where necc.......easy peasy......be better if the first half was something like 30mm with a step down to 22mm 1/2 way around the loop.....but prob not necc with just those few rads.......
find an old guy.....these young'uns seem to be clueless.......

 

[hunter27]

Should not be a problem, start in 28mm and reduce to 22mm after 2 or 3 rad's. A 24KW gas boiler would only generally only have 22mm connections anyway but if the runs are long it's good practice to up size to larger pipe as soon as you leave the boiler.

 

[Kayos]

7 rads?

I would just use 22, if you’re not using a combi then a slightly bigger than normal pump and some 28mm around the boiler but that’s it

20kw heat load and probably 3-5kw heat loss through the pipes

 

[fizzy]

They need to be big rads - and we are going to have to use an oil boiler.
I thought it would be simple. Thanks for the advice everyone.
The only awkward part for the pipes is they will have to cross a doorway on the right hand side. Up and through the ceiling or down and dig a channel in the concrete floor?

 

[Kayos]

They need to be big rads - and we are going to have to use an oil boiler.
I thought it would be simple. Thanks for the advice everyone.
The only awkward part for the pipes is they will have to cross a doorway on the right hand side. Up and through the ceiling or down and dig a channel in the concrete floor?

If burying they need to be well protected, concrete has a very corrosive effect on copper

 

[fizzy]

If burying they need to be well protected, concrete has a very corrosive effect on copper

I thought to make a shallow trench with a steel plate over it. Flush into the floor of course.
Less work for the pump if not going up hill.

 

[fizzy]

Sorry to be a pain but could someone do me a very simple diagram of the pipe run for the rads.

I take it I run the pipe along one wall and then loop it back along the same wall. Like a trombone slide?

Does the water flow into and out of each rad in turn? Like something wired in series?

 

[voipio]

Parallel would be the way to go i.e. each radiator would have one connection to the boiler flow, and the other to the return. The far end of the loop might benefit from a bypass valve to help in balancing the system.

Will there be thermostatic valves on each rad? If so, one rad would need to be fitted without thermostatic valve, and essentially be always on.

Not forgetting timer, header or expansion tank, and a room thermostat in the same space as the radiator having no thermostatic valve was fitted. Probably the best place for this rad would be the far end of the loop.

The pipe run over the doorway will be a problem for airlock formation. Automatic vents could be fitted at the highest points of the flow and return pipes, but would need to be easily accessible, in case of leaks.

 

[fizzy]

Parallel would be the way to go i.e. each radiator would have one connection to the boiler flow, and the other to the return. The far end of the loop might benefit from a bypass valve to help in balancing the system.

Will there be thermostatic valves on each rad? If so, one rad would need to be fitted without thermostatic valve, and essentially be always on.

Not forgetting timer, header or expansion tank, and a room thermostat in the same space as the radiator having no thermostatic valve was fitted. Probably the best place for this rad would be the far end of the loop.

The pipe run over the doorway will be a problem for airlock formation. Automatic vents could be fitted at the highest points of the flow and return pipes, but would need to be easily accessible, in case of leaks.

Yes I was planning on a thermostatic valve on each rad. Having one always on won't be a problem.

As regards header tanks etc in my house I have a Worcester heatslave 20/25 - it only seems to have an internal tank as it is some sort of combi boiler? Do I still need a header tank? I was thinking of using something similar - you can get mint used ones for £400 or so. I would install everything - then get our oil boiler bloke to check it all out.

 

[Kayos]

Get a system boiler, only needs flow and return plus a cold mains for the filling loop

 

[Olderisbetter]

I used to pipe up hospital wards and we always went under a door with a channel in the concrete, If it was copper pipes they had to be wrapped in tape and then insulated and then wrapped on tape again, It is more work but going around a door way is a bleeding issue... A few years back we fitted a oil fired Worcester combi boiler which has not really had any issues.

 

[gaz1]

a few questions here boiler in warehouse can the pipes be run high above doors?

is it u p stairs . office?

if yes run it that way and run it to see each rad

run it in 22mm at 30m swap to 15mm pipe through to middle one and split off to other rads the last rad bathroom one tee off at 22/15/15 and run back to bathroom this will equal your system out better

 

[fizzy]

All on the same ground floor level gaz

 

[fizzy]

I used to pipe up hospital wards and we always went under a door with a channel in the concrete, If it was copper pipes they had to be wrapped in tape and then insulated and then wrapped on tape again, It is more work but going around a door way is a bleeding issue... A few years back we fitted a oil fired Worcester combi boiler which has not really had any issues.

Yes that will prob be the plan.
Floor should be fun though. Old factory so heavy duty reinforced floors.

 

[brightspark]

Yes that will prob be the plan.
Floor should be fun though. Old factory so heavy duty reinforced floors.

use a 4 and a half inch inch angle grinder and a diamond blade in it to cut the concrete out

 

[fizzy]

use a 4 and a half inch inch angle grinder and a diamond blade in it to cut the concrete out

And there was me thinking I would need to hire something!.
Doesn't need to be a big trench. Just the width of the doorway and a few inches deep.

 

[gaz1]

run the pipes samee way on warehouse side cut in on 'middle room and drill 18'mm . holes pipe up those rads .
everything all above door height warehouse side

 

[pressbrake1]

Remember expansion joints . My old gym owner didnt bother and the pipe popped off the wall