Use insulation to keep hot water hot

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Use insulation to keep hot water hot

If your hot water system is a long way from where the hot water is used, you can lose heat in the water pipes. If you can’t move your hot water system, you should insulate the hot water pipes with R1-rated insulation that is at least 10mm thick. This will help to minimise heat loss.

Insulating your electric hot water storage tank will also reduce heat loss and save money.[1]

Implementing this can:

  • reduce standby heat losses by 25–45%, and
  • save about 4–9% in water heating costs.[2]

One way to do this is with an insulation jacket:

If your business has exposed external hot water pipes, then it pays to have these insulated as well. The ‘Victorian Employers’ Chamber of Commerce and Industry’ (VECCI) estimates that fitting insulation to 100mm pipework could save you up to 800kWh per metre.[3] The insulation lagging is only $40 per metre so the savings quickly add up, especially if you have a few metres of exposed piping.

They also estimate that insulating a hot 100mm flanged valve could save up to 800kWh. An insulated jacket for a valve costs about $160, so the return on this is usually within a short time frame.

Fitting this insulation is quite easy, but it can also be done by your maintenance contractor the next time they check your hot water system. Just remember to give notice that you want this insulation installed.


Heat losses from hot water systems

Heat losses from hot water systems Insulating your hot water set-up is very important. According to, heat loss from hot water storage tanks and the associated fittings and pipes is substantial:


• large electric storage tanks and their fittings can waste up to 1,000kWh each year



• this is equivalent to the energy required to heat 50–60L of hot water each day


The above figures are only for home-based hot water set-ups. If you use bigger uninsulated hot water systems, the heat losses will be higher still.[4]