Energy Matters Forums

[munter]

Excellent comparison data - Thanks Gordon. This is just the data I need to convince the missus that we should plumb our solar/gas hot water in to the dishwasher when we renovate. We will probably take the water from the downstream side of the tempering valve to try to avoid hot water damaging seals but still making a good contribution to reducing the energy requirements. I would guess that the first rinse will typically just use cold water between the gas boost and the washing machine and that it will use hot water from there onwards. Given that our household consumption is about 5 kwhrs/day and our dishwasher uses about 20% of that we could make a 10% reduction in our overall power consumption through this change!

[Tracker]

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Some interesting findings indeed !

Don't forget - To those who read these findings and think that it might apply to them also.......
The situation is that folk are talking about SOLAR-Hot-Water... FREE Hot Water.

The valid argument is that by using HOT water, the washing time is reduced, and hence there is considerably less electricity used. TRUE

If, however you have to pay to heat the water, then the reverse situation exists. Most all dish washers rely on using COLD water for initial rinses, and then gradually heat the water to a set temperature.

To use Electrically-Heated water for all washes, might reduce the wash time, but will likelky cost more in total energy consumption and hence the $$$ ..
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[Smurf1976]

If, however you have to pay to heat the water, then the reverse situation exists. Most all dish washers rely on using COLD water for initial rinses, and then gradually heat the water to a set temperature.

To use Electrically-Heated water for all washes, might reduce the wash time, but will likelky cost more in total energy consumption and hence the $$$ ..

Agreed though it does depend on how you are actually heating the water, and how long the pipe run from the water heater to the dishwasher are.

In my case it's a heat pump HWS on off-peak tariff sitting almost straight under the dishwasher. That's about a 6:1 cost ratio (two thirds reduction in energy use, and the power used is at half price being off-peak) in favour of the heat pump per kWh of heat put into the water. Even if half of it gets wasted, it's still a bit more energy efficient and considerably cheaper than letting the dishwasher heat its own water.