Hot water accounts for 29% of the energy used by an average New Zealand home. A hot water cylinder wrap can significantly help to save energy.
Many households use the hot water cylinder cupboard for drying clothes in. A well-wrapped hot water cylinder will still warm the cupboard enough to dry clothes in, therefore keeping the utility of the cupboard while increasing the performance of the cylinder.
Prices and savings
A hot water cylinder wrap costs between $60 and $90. It will pay itself back within 18 months. You may be eligible for a subsidy through the Government's Warm Up New Zealand: Heat Smart programme. Check out www.energywise.govt.nz to find out more.
Who can install a wrap?
Hot water cylinder wraps can only be installed on electric hot water cylinders. You can install the wrap yourself.
If you have an A-grade cylinder (there should be an 'A' on the side of the cylinder) it may not be economically worth installing a wrap, as it is well-insulated already. Since these cylinders have only been on the market in recent years, a wrap will save power and money on older cylinders. If you touch your cylinder and feel any warmth - even just a little - a wrap will retain this heat.
To install a cylinder wrap you need to have good access to the cylinder. You will need at least 5 cm all around the cylinder - more will make the installation easier. If you have easy access to the cylinder, installing a wrap is not difficult and will take about 2 hours. Don't forget to install pipe-lagging insulation to at least the first metre of hot water pipe that comes out of the cylinder, as this will also save you money.
Insulation value
There are different brands of cylinder wraps on the market. Ensure that the wrap is the correct size for your cylinder. The insulation value (R-value) of wraps may also vary. The R-value gives an indication of the insulation value of a wrap: the higher the R-value, the more heat retained. Not all wraps have the insulation value marked on the packaging though. The following table gives the R-value of the different brands that are known to Environment Canterbury.
| Brand |
R-value
(as per manufacturers’ specifications) |
| Eco-wrap (Autex) |
1.0 |
| Tasman |
1.3 |
| Terra Lana (wool) |
1.3 and 1.8 |
| Insultec |
1.2 |
Where do you buy a wrap?
Hot water cylinder wraps can be bought at most hardware and DIY stores.
Some organisations like Community Energy Action in Christchurch (CEA, 374 5698) can install hot water cylinder wraps for people who are not keen or able to do it themselves
Temperature setting
Check the temperature setting on the hot water cylinder; the ideal temperature is 60 degrees Celsius (140 degrees Fahrenheit). A higher temperature is usually not necessary, may cause scalding and costs you extra money.