Hot Water Cylinder Wrap

Why install a Hot Water Cylinder Wrap?
Hot water accounts for around 29% of the power used by an average New Zealand home.  A hot water cylinder wrap can reduce that percentage substantially and save up to 10% on your electricity bill!
Many households use the hot water cylinder cupboard for drying clothes in.  Because your unwrapped cylinder loses heat every minute, it is more energy-efficient to install a wrap and dry clothes outside or in the dryer for several minutes than it is to lose heat every minute of the year.  If you install a wrap and switch to using the dryer two hours a week, you can save up to 2.5 times the energy!

Installing a cylinder wrap (picture www.smarterhomes.co.nz)

Prices and savings
A hot water cylinder wrap costs between $60 and $90 that will generally be recovered in 2 years through energy savings.

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 quite well insulated already.  However, these cylinders have only been on the market in recent years.  If your cylinder is older it is not likely to be an A-grade - so a wrap will save electricity and money.  If you touch your cylinder and feel any warmth - even just a little - a wrap will assist to 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 takes about two 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.  As the size may vary, make sure the wrap is the correct size for your cylinder.
The insulation 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 be on the market.
Brand R-value (as per manufacturers’ specifications)
Eco-Wrap (Autex) 1.3
Novawrap (Energy Options) no R-value listed
Pink Batts  no R-value listed
Terra Lana (recycled wool) 1.3

Where do you buy a wrap?

Hot water cylinder wraps can be bought at most hardware and building supply stores.
Temperature setting
While you are working on the hot water cylinder, it is advisable to check the temperature setting on the thermostat.  The temperature should be no more than 60°C.  A higher temperature is usually not necessary and may increase the risk of scalding and will incur higher energy costs.

Links to manufacturer’s websites (in alphabetical order):

• Eco Wrap  http://www.autex.co.nz/insulation/eco.html
• Novawrap  http://www.energyoptions.org.nz
• Pink Batts  http://www.pinkbatts.co.nz
• Terra Lana  http://www.terralana.co.nz/products/building/1585.html