In article ,
Robert Frame wrote:
I am installing an oil fired central heating and hot water system.
I plan to use 22mm copper pipe as the main primary feed and return,
with 15mm pipe as the radiator supply and return.
Should I run the 22mm pipe as close as possible to all radiators?
Am I best avoiding long runs in 15mm pipe?
Can anyone direct me to good in depth guides on central heating
installation and plumbing?
Anything I have found so far is either very basic or generalised.So
any info on the installation for a semi detached house with 11
radiators and 1 hot water tank would be greatly appreciated.

1. the myson.co.uk provides a downloadable program for sizing rads and
brequired boiler ouputs. You calculate heat loss from the rooms by
inserting sizes of walls, windows, materials etc.

2. my local library has a good section on plumbing and house building books

3. the above books tell yuo waht size pipes to use. Small 15 mm pipes can
only serve rads outputs of around 6kW, 22m can serve 12kW? (get exact
figures from books, or web sites/DIY faq).

4 My oil boiler, located at one of of my end terrace, has 28 mm to a
T-pice next to the boiler. From this T-piece;
a) 22 mm runs to the upstairs and then goes to 15mm when it enters the
floor void (for 3 beds plus one landing rad),
b) 22 mm runs through the kitchen (and kitchen rad) to the dining room rad
and then changes to 15 mm for the hall and lounge. There is also a
T-piece in the 22 mm near the boiler for a 15 mm run to the bathroom, at
the back of the kitchen.
This may give you some idea.
Neil

I'll be selling my oil boiler and tank soon?