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Teacosy? Think Valvecosy

Valvecosy cutaway
Valvecosy heat escape comparison
Valvecosy in a packet

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If you remember that great bit of nana technology the “tea cosy” you’ll understand that by insulating a tea pot it keeps the water hot for longer. However have you considered how this “cosy” concept can be used at a larger scale in your home?

Hot water services are one of the biggest energy users in the home. Minimising how much energy a hot water service uses will save greenhouse gas emissions and save you money. The best thing to do is to install a modern energy efficient solar boosted hot water service but not very nana like if the one you have is still working.

So what options are available to renters to minimise hot water service energy usage?

  1. Use less hot water – Anyone can do that, it’s free and sharing a shower can be fun also (yes nana probably did that too!)
  2. Make sure that the thermostat is on the low setting – When nana had a briquette fired hot water heater she would have only lit when she had to. A modern equivalent is the thermostat. If you’re not regularly running out of hot water, boosting the water to a high temperature and keeping it at that temperature 24 hours a day is wasting energy. The hardest part is to identify where the thermostat is. The user manual or a call to hot water service manufacturer will advise on how to turn down the thermostat.
  3. Consider insulating your storage tank – Think really big cosy! Despite being insulated all hot water service tanks lose heat to the environment. The more exposed the position the more heat is lost. Consider insulating your hot water service by wrapping it with insulation. Be careful that you do not block any vents and make sure that you follow all the manufacturer’s warnings in the applicable user manual.
  4. Insulate the pipes – Think of the pipes as a really long teapot spout. Without insulation as soon as hot water leaves the hot water service tank and travels along the pipes it is losing heat to the air.  This means the water will arrive at the outlet cooler and you’ll compensate by using more hot water using more energy. In order to save heat loss the pipes can be insulated. Make sure you stay away from the temperature and pressure relief valve. The folks at Green Renters have already covered this topic. Lagging the pipes with split nitrile rubber foam is another option. This is available at most hardware stores and can be easily installed (and removed if you feel like taking it with you). Unfortunately in a rental situation you may not be in the situation to be able to insulate the pipes as they travel through walls or ceiling cavities.
  5. Insulate the pressure relief valve – you may have noticed that when you were installing the pipe insulation that the pressure relief valve was quite warm. Heat is being lost through the valve 24 hours a day. The pipe fittings and valve are responsible for ~12% of the standby heat loss from a hot water service. Insulating the valve will save energy but must be safely done in a way that doesn’t compromise the operation of the valve. A product such a Valvecosy™ is a way to safely insulate the valve and save up to 55kWHrs each year. The thermographs below show the heat loss from a valve without and with Valvecosy™.

For renters the benefit is that it is easily installed without tools and can be easily removed and taken with you when you move.  Valvecosy™ is also Australian designed and made. For more information on Valvecosy™ and where to buy visit

Unfortunately Valvecosy doesn’t come in the funky retro colours and patterns that nana used to make her teas cosies in but it is made to last and be just as effective. I hope you give it a thought.

Christian Groves, Valvecosy designer