TECHNICAL BULLETIN
ISSUE 29
JULY 2018
MICROBORE HEATING SYSTEMS HOW THEY WORK, THE ISSUES & HOW TO REPORT ON THEM DR LISA BLAKE TECHNICAL MANAGER, SAVA PHIL PARNHAM MRICS DIRECTOR, BLUEBOX PARTNERS
Many heating systems in the UK still use microbore piping. Here, we take a look at the advantages and disadvantages of microbore piping and how best to report on it.
heat and a smaller capacity boiler can be used. The reduced surface area of the pipes also means less heat loss. Microbore systems are always two-pipe systems using the flow and return convention. Traditional older systems can often be one-pipe systems, where the heat flow from the boiler is one continuous loop.
History of microbore piping
Microbore pipes were introduced in the 1970s and were hailed as an innovative plumbing material for central heating systems. The piping comes on rolls and consists of copper pipe with a thickness between 8 mm and 10 mm. The narrow pipe was flexible enough to be gently bent by hand, reducing the need for joints and soldering which can cause additional heat loss and leakage. This meant that installing the pipe-work for a central heating system could be regarded as a DIY task, saving the homeowner time and money. More recently, as the price of copper has increased, and we are more environmentally aware, there is renewed interest in microbore piping.
How does microbore differ from conventional systems?
Microbore piping is not only flexible and easy to install, but the narrower pipes also use less water. This means that microbore heating systems need less boiler
Figure 1 - coil of copper micro-bore pipe
Figure 2 - one and two-pipe systems
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