Drain water heat recovery and what to look for when choosing a model. Basic information including savings calculation, 3rd party calculators. This is the first of several series on drain water heat recovery.
Drain water heat recovery 101 - savings, how to shop and conclusion
DRAIN WATER HEAT RECOVERY
IN A NUTSHELL
A- How to shop
B- Residential Savings
Price your drain water heat recovery unit based on energy it can recover in kW = $cost/kW rating
*Refer to last slide for link on kW ratings for drain water heat recovery units / (as an alternative you can use % efficiency instead of kW)
Similar to a cars efficiency = miles per gallon or L/100km
Some examples (cost per kW):
ThermoDrain™ TD336B = $570 and is rated at 7.0 kW ($570/ 7.0kW)= $81.42/kW
ThermoDrain™ TD342B = $613 and is rated at 7.7 kW ($613/ 7.7kW)= $79.61/kW – Best buy
ThermoDrain™ TD348B = $656 and is rated at 8.2 kW ($656/ 8.2kW)= $80.00/kW
*prices taken from EcoInnovation Technologies website and includes drain couplings. Pricing is MSRP. kW ratings taken from Natural Canada Website and are CSA verified.
NOTE 1: Length is never a factor in determining efficiency. The longer a unit, the more complicated it can be to install. Complicated = more
NOTE 2: Make sure that the kW rating is a CSA B55.1 certified tested number
Electric Hot water tank with a ThermoDrain™
0.08$ kWh energy cost = savings of $12829 over 50 years = Rate of return 24% - payback 4.6 years
0.12$ kWh energy cost = savings of $19243 over 50 years = Rate of return 35% - payback 3.1 years
0.21$ kWh energy cost = savings of $33676 over 50 years = Rate of return 59% - payback 1.8 years
*Only energy recovered from shower water considered in calculations. Based on 4 showers per day, 10 minutes per shower, equal flow configuration, 9.5 lpm (2.25 gpm), $700 total cost
installed. Inflation of 2% per year. Estimates using efficiency test results certified to CSA B55.1. This is an estimated calculation and results may vary.
These ThermoDrain numbers are unreal but yet - TRUE!
1. It will last 50+ years and requires no maintenance.
2. It will provide 60 more minutes of free shower time on a 40 gallon tank for a total of 90 minutes.
3. It will save you $33,000 dollars during its 50 year service and only cost you $700
4. After 50 years, it will be worth more money that what you paid for it (100% copper)
5. It is 100% recyclable so you can recycle it to make another one
6. It is guaranteed to give you a double digit rate of return – as long as you use it.
7. It will pay for itself 48x over.
All drain water heat recovery units efficiencies are measured in Kilowatts (kW).
kW is a measurement of energy/ power kWh is the quantity of kW used over 1 hour.
The higher the kW number = the more you are going to save
Natural Resources Canada has the Btu, %, kW and kWh ratings of all drain water heat recovery
technology listed on their NRCAN DWHR Energy Efficiency Ratings
3rd Party Drain Water Heat Recovery Calculators.
NOESIS DWHR CALCULATOR
1) Visit Natural Resources Canada Website and compare the efficiency results. Are the results
CSA B55.1 certified? NRCAN DWHR Energy Efficiency Ratings
2) Natural Resources Canada recommends a minimum of 42% efficiency for an EnergyStar for
New Homes application. This is the ThermoDrain TD342B model.
3) Go shopping - Calculate and determine the cost/kW and compare!
Other factors to consider: The longer the unit, the more expensive and difficult it may be to install, modifications to current plumbing system
may be required to retrofit therefore adding to the total cost. Are there joints in the copper coils, if so these could be considered potential
leak points. Some manufacturers have none while other have up to 12 joints. Do the drain couplings come with the unit? Shipping charges,