WHAT IS DRAIN WATER HEAT RECOVERY?

How does residential drain water heat recovery work? What can it do for you?

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WHAT IS DRAIN WATER HEAT RECOVERY?

A residential drain water heat recovery device consists of a copper potable water tube wound around a central copper drain tube

The drain water heat recovery unit replaces a section of your vertical drain stack where warm water from the shower usually drains. 

Wastewater from your shower or other sources of heated water heats the inner copper drain tube of the drain water heat recovery unit as it flows down the drain. At the same time, cold water is flowing in the outer copper potable water tube that is wound around this central drain tube. The outer coil is trying to cool down the warm central drain pipe and the result is that a heat exchange takes place. The cold water in the coil extracts the heat energy from the drain pipe and is heated using waste energy.

The preheated water in the coil feeds the water heater and/or the cold side of the shower. Two things occur;

  1. At the shower, you are now mixing warm water from the drain water heat recovery unit with hot water resulting in the use of less hot water in the shower to achieve the desired shower temperature.
  2. Instead of feeding cold water to the water heater, you are now feeding it warm water. For tankless hot water heaters, this means a significant increase in the flow rate of hot water. For tank hot water heaters this means up to 3x more hot water for showering. The overall saving is up to 40% on the cost of heating water

Savings

Up to

Recyclable

Environmentally Responsible Product

1   X

More Hot Water!

Drain water heat recovery price

When shopping for a drain water heat recovery device, you want the most efficiency for the price. The length is not a factor when comparing between manufacturers. 

Always look at the cost versus efficiency

Construction of the drain water heat recovery devices vary from one manufacturer to another. When comparing the cost of the drain water heat recovery unit, take the efficiency of the unit and divide by the price. This will give you the price you are paying for 1% of efficiency. The lower the number, the better.  

Some manufacturers offer pre installed fittings and drain couplings to facilitate installation costs.

Typically where drain water heat recovery is required by code, the efficiency requirement (NOT LENGTH) needs to be is equal to or above 42%. This must also be a CSA B55.1 verified number. 

Differences between drain water heat recovery brands

  • Thinner potable water walls and require longer, heavier units to achieve the same efficiency as our compact high efficiency models.
  • They also do not come factory equipped with PEX fittings.

Fortunately, most drain water heat recovery devices are now third party verified for performance under the CSA B55.1 standard. The question is, are you shopping by length or by efficiency. The difference is the smarter shopper will choose the later.

+ 100 K

+100,000 Installed ThermoDrains

+ 100000 ton

Removed CO2 in Atmosphere/Year

Residential

Commercial