Drain Water Heat Recovery Horizontal or Vertical installation? Why?

In the past few years it has been a common question that many people have asked me.

"Can the ThermoDrain or Eco-GFX drain water heat recovery unit be installed horizontally?"

In a nut shell, yes you can.
Is it recommended? No!

Why?

When I get this question, it leads me to believe that the person asking the question does not quite understand the concept and functioning of the drain water heat recovery unit. I can see how some people would believe that the unit could easily be installed in any configuration.

Some facts about drain water heat recovery in regards to its attitude (installed position)
1) The unit is never filled up with water (misconception)
2) The unit should be installed perfectly vertical for optimum efficiency
3) The units inside surface area is what transfers the heat and there is a fine equilibrium between the surface area required.
4) Longer and bigger does not mean better and more efficient (Something I will cover in another blog posting)

The drain water flows down the cooled walls of the inside of the heat exchanger. This drain water contains the energy we wish to extract.
The reason the ThermoDrain is so effective as a passive heat exchanger is due to the film that is formed on the inside walls.

TO UNDERSTAND THE CONCEPT.........

Take a boiling cup of water and extract the energy from it as quickly as possible. What would be the fastest and most effective way?
1) Leave it in the cup
2) Leave it in the cup and cool the outside of the cup
3) Pour the cup of boiling water over a pan
4) Pour the cup of boiling water over a flat pan
5) Pour the cup of boiling water over a flat cooled pan
6) Pour the cup of boiling water over a flat cooled copper pan

Scenario #6 pretty much covers the concept of the technology and why the ThermoDrain or Eco-GFX should not be installed in a horizontal position. Tests have shown that when the ThermoDrain is perfectly positioned in a vertical position, you will obtain the maximum efficiency. In the horizontal position, you will achieve only a 10% efficiency.

My next post will deal with what does the efficiency of a drain water heat recovery unit really mean and why it is so important.

Drain Water Heat Recovery - ThermoDrain and EcoGFX

I love Wind energy, Solar energy and geothermal energy but simply cannot afford it.



Here is a challenge for you.

Find me a 10kW hot water heater that......
1) Lasts 50 years and requires no maintenance
2) Is 100% recyclable
3) Uses waste energy to produce its own (not powered by new energy)
4) Is 55% efficient and costs between $500 and $600
5) Works only when I need it
6) Allows me to reduce my original hot water tank by 50%
7) Increases my shower time capacity by 3x (example: 40 gallon tank will give me 30 minutes of the shower time and when this "hot water heater" is installed it gives me up to 90 minutes)

Submit your ideas.