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10 Secrets why Geyser Wise will save you money and the environment

We all know that hot water heating can account for 40 – 60% of your domestic electricity usage. With electricity tariffs set to increase annually, anything you can do to reduce your geysers electricity consumption, will therefore lead to substantial savings.

In advising clients how to reduce their geyser’s electrical consumption, knew the Geyser Wise system works but wanted to investigate, first-hand, the claims and promises of saving electricity and money. Attended the Geyser Wise training at the Solar Academy where Deon van Blommenstein explained excellently how the system works and what the developer Meinhard Fourie was hoping to achieve. The research undertaken by the Cape Peninsula University of Technology provided a valuable resource and test data from various installations were also analyzed.

So in layman terms, why will Geyser Wise save you money?

You have total control. The programmable controller is easy to use and you set the temperature and time the element is on heating water. The controller displays, in real time, the temperature of the geyser making assessment, evaluation and adjustment for greater efficiency possible.

The element is being used for less time. It’s that simple, less time drawing electricity means savings and greatly reduces the “top up” scenario. The best analogy to compare is the boiling of a kettle. You boil a kettle and a couple of minutes later you go to make your tea. Now even though the water has just boiled you put it on again and it takes longer (more electricity) than expected to re-boil.

You control the temperature. This is important; as most people have no idea what temperature their geyser is set for? (Usually find at 70 degrees C). Massive amounts of electricity are wasted heating and maintaining this temperature, when the ideal water temperature for domestic washing is between 37 – 41 degrees C.
For my family of 2 adults, nanny and 3 year old, I  have my geyser set weekdays at 50 degrees C. for 1.5 hrs in morning and 47 degrees C. for 2 hrs in evening. For weekends at 60 degrees C. for 2 hrs in the morning to prevent the unlikely event of Legionnaires disease. These settings were more efficient but the cents saved compared to partner ranting when shower went occasionally cold, was not justifiable!

The amount of heat loss is reduced. By using the majority of the heated water and leaving the geyser at a low temperature (near ambient temperature) during the times when do not need hot water, the standing losses are reduced. Before require hot water again, the timer starts heating the water and the cycle repeats.

The temperature dropping on the display can give valuable information. Being aware of the standing losses prompts most people to insulate the geyser and pipes but please use the correct insulation. ( Topic for another journal entry) If the temperature is dropping constantly it could indicate leaks. A leaking tap and a leaking pipe in a wall, have been identified this way.

We are creatures of habit. The control unit can be programmed to your weekday and weekend needs down to the nearest minute and degree of temperature to accommodate your families lifestyle. What about unexpected events or guests? No problem, one push on the override button turns on the element until it achieves the programmed temperature. Then it switches itself off and goes back to the programmed settings. Easy and you don’t have to remember to turn it off is an added bonus.

Can program element to heat out of peak hours, when certain tariffs are cheaper (In the future hoping for cheaper off peak residential tariffs! – The more people believe it will happen the greater chance it will happen) Heating in off peak hours benefits the country substantially, as by moving the usage out the peak times it reduces the operational capacity that is needed . This creates a buffer that is critical, as it allows essential maintenance to occur and reduces black-outs.

Compatible with solar geyser installation you have installed or are planning to. The controller links up to the solar pump and pumps the solar heated water when there is a slightly higher temperature than in the geyser. So even if the day is cloudy, any heated water heats the geyser, reducing or eliminating the usage of the element at the end of the day.

The hours used are recorded.  You can track your use and make the necessary adjustments, comparisons, bragging rights around the braai etc.

The positive spin off will probably spill over to other areas and you will look with fresh eyes to opportunities and possibilities for savings and being more efficient. Enjoy this feeling that you are making a difference and I hope this helped you.

By Mathew Streatfield


Welcome, I am Mathew, a civil engineer with 20 years experience in construction. I now advise on energy efficiency in residential and light commercial buildings, and I would love to help you.

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