Insulating the pipework and valves of a hot-water and heating systems could help cut heat loss or heat gain by up to 90 %. In one or two years, the investment could be recovered, and savings made.

Take an office working on a single-shift system, for example. Fitting insulation to 100 mm pipework would cost around € 23 (£ 20) a metre but save € 23 (£ 20) a metre, assuming a gas price of € 0.03 (2.5 pence) per kWh. That means a payback period of just one year.

An un-insulated valve or flange can lose the same amount of heat as one meter of un-insulated pipe. Insulating a hot 100 mm flanged valve would cost around € 90 (£ 80) and save around € 23 (£ 20), recouping the cost within four years.

There are different insulating materials (glass mineral fibre, aluminium foil faced, pre-formed rock mineral fibre aluminium foil faced, pre-formed polyethylene foam, etc.) suited to diverse applications:

• Straight pipework is usually insulated with pre-formed lengths fixed with metal bands or high-temperature tape
• Insulation for external pipework is weather-proofed to stop it absorbing water and losing its insulating properties
• Valves are best insulated using flexible jackets fixed with quick release fastenings