HOW DOES DRAIN WATER HEAT RECOVERY WORK?
A simple, comfortable and maintenance free passive water heater booster that uses waste heat energy to preheat incoming cold water.
IS DRAIN WATER HEAT RECOVERY WORTH IT (DWHR) ?
DWHR recovers heat from water that would otherwise be lost down the drain. It works best with simultaneous flows like showers, where there is a demand for hot water at the same time as hot water is going down the drain. The recovered heat can be used to preheat cold water going to the hot water tank or for other purposes permitted by codes and regulations.
A ThermoDrain unit consists of copper pipe tightly wound around a vertical section of copper drainpipe. As water flows down the drainpipe, it clings to the inside surface of the drainpipe. The heat from the drain water is transferred through the copper drainpipe to fresh cold water flowing in the outer copper coil.
The warmed water is then sent either to the hot water tank or other permitted end-use. In either case, the amount of energy needed to provide hot water is reduced. ThermoDrain systems provide greater potential for energy savings as the number of simultaneous flows increases.
ThermoDrain units vary in terms of pipe size, orientation of the drain line, heat exchanger design, cost and energy savings achieved.
For tankless hot water heaters, this means a significant increase in the flow of hot water. For tank hot water heaters this means up to 3x more hot water for showering.
In the shower, you are now mixing warm water with hot water and therefore use less hot water in the shower. Overall saving is up to 40%* on the cost of heating water.
DRAIN WATER HEAT RECOVERY BENEFITS
Get more hot water using less energy
- Get three times more hot water with the same water heating tank.
- Tankless on demand hot water systems will provide a higher flow rate.
- Reduce a home’s carbon footprint by one ton of CO2 per year, the equivalent of what one acre of pristine forest can remove.
Reduced energy consumption
- Captures the heat from wastewater primarily from showers.
- Reduced energy costs
- Reduces utility bills.
Easy to install and requires no-maintenance
- 100% maintenance free with no moving parts
- 100% recyclable
- Optional factory installed crimp PEX fittings for easy installation
- Backed up with a 10 year limited warranty
Ten year limited warranty
The ThermoDrain is 100% recyclable and is an environmentally responsible product.
THERMODRAIN IS EASY TO INSTALL WITH
PRE-INSTALLED PEX FITTINGS
The ThermoDrain, drain water heat recovery installation is EASY. There is no soldering required with the optional patent pending crimp style PEX fitting feature. The ThermoDrain is installed vertically on the main drain stack in order to capture most of the hot waste water used. The preheated potable water from the ThermoDrain may be fed in a variety of configurations to either or both the water heater and cold side of the plumbing fixtures using hot water. No maintenance is required, it has a very low pressure drop and has been designed with outstanding efficiency. The ThermoDrain is easy to install and takes no more than 45 minutes with some plumbing experience.
THERMODRAIN, DRAIN WATER HEAT RECOVERY SIMPLE INSTALLATION OPTIONS
In new home construction, the preferred installation configuration is to send preheated water from the ThermoDrain to the water heater cold supply and to the cold water supply of the shower because it provides the most energy savings. In renovation projects, with limited access to the bathroom plumbing or the water heater makes it more practical to use the other two configurations as shown below.
BY USING THERMODRAIN, DRAIN WATER HEAT RECOVERY YOU CAN TURN YOUR 28 MINUTE SHOWER INTO A 90 MINUTE SHOWER & SAVE UP TO 40% ON YOUR HOT WATER BILL!
With ThermoDrain, drain water heat recovery you will save money, increase your the hot water available for in your home for showering and reduce your overall energy consumption. A constant recycling of waste heat energy means longer showers on the same tank. A 40 gallon hot water tank gives you roughly 28 minutes of continuous shower time. Add the ThermoDrain into equal flow and you will get roughly 90 minute continuous shower or nearly three times more shower time while reducing your hot water bill by up to 40%*. This test was done at the Canadian Center for Housing Technologies in Ottawa.
*Hydro Quebec estimates http://www.hydroquebec.com/residential/energy-wise/hot-water/used-water-heat-recovery.html
USING AN TANKLESS WATER HEATER?
Imagine how your tankless ThermoDrain will introduce warm water to the water heater from the ThermoDrain and increase the flow rate when showering. When you are using hard cold water, the ThermoDrain will increase the life expectancy of your heater by reducing scalding that causes calcium build up in your heater. You can now enjoy much more hot water and enjoy a long lasting hot water heater.
LOWER ENERGY CONSUMPTION = SAVINGS!
As a homeowner, you may be interested to know that hot water is the 2nd highest energy user after home heating. Growing energy costs requires that we stop wasting precious heat down the drain. The ThermoDrain is the most cost effective way to save on utility bills year after year while adding value to your home. On average, 20% of a homeowner’s energy bill is from heating water.
If replacing your standard shower head with an ultra low flow model is what you had in mind but fear the lack of flow from these, consider that a ThermoDrain will provide the same energy savings without having to compromise.
DOES DRAIN WATER HEAT RECOVERY WORK?
IF SO, WHAT DO THE NUMBERS LOOK LIKE?
Drain water heat recovery really does work. The numbers are independently verified by several parties and products used in homes must be tested for efficiency before being installed. There is a CSA standard B55.1 that verifies the efficiency of a given drain water heat recovery unit under strict operating parameters. This efficiency is then labelled on the unit in according with this same standard. Government and utilities have all verified claimed efficiencies prior to the release of this CSA standard.
COMPARING TWO DIFFERENT LENGTH DRAIN WATER HEAT RECOVERY UNITS
Below are two scenarios that demonstrate under the same operating conditions the temperature increase potential using drain water heat recovery. A 3″ x 42″ unit versus a 3″ x 60″ unit. The 42 inch length unit is capable of preheating water from from 50°F to 71.4°F while a 60″ length unit is capable of preheating water from 50°F to 75.75°F.
Scenario 1 (42″ long drain water heat recovery unit)
- TD342B 42.8% efficient
- Drain water temperature 100°F
- Cold water temperature 50°F
- DELTA T = 50°F
- Temperature increase = 50°F x 42.8% = 21.4°F
- 50°F cold + 21.4°F ThermoDrain increase = 71.4°F ThermoDrain exit
Scenario 2 (60″ long drain water heat recovery unit)
- TD360B 51.5% efficient
- Drain water temperature 100°F
- Cold water temperature 50°F
- DELTA T = 50°F
- Temperature increase = 50°F x 51.5% = 25.75°F
- 50°F cold + 25.75°F ThermoDrain increase = 75.75°F ThermoDrain exit
WHAT MODEL DRAIN WATER HEAT RECOVERY UNIT SHOULD I USE?
Where drain water heat recovery is code required, the code usually states are minimum requirement of 42% efficiency. This number must be verified by a third party to the CSA B55.1 standard. If you are not required by code to use drain water heat recovery and wish to install and do not know where to begin, look at the cost versus efficiency in percent. Each dollar invested in drain water heat recovery is buying you a point in efficiency. By using this graph, you can determine the efficiency versus length and cost out what unit suits your needs. In the case where you are building to a NETZERO or PASSIVEHOUSE standard, you will want the longest unit possible because the cost of the energy recovered using this technology beats out cost per energy recovered.
Your selection should take into account the available length of the 3” drain pipe where the unit will be installed as well as the efficiency you wish to obtain. The models proposed are all suited for residential installation and should be located on the vertical drain stack that services at least one shower and most of the appliances using hot water.
THERMODRAIN, DRAIN WATER HEAT RECOVERY IS AVAILABLE IN METRIC SIZES
We do offer the ThermoDrain in metric sizes. 100 and 75mm drain diameter x 22mm coil for countries that are currently using metric standard pipe sizes. The drain couplings supplied are also metric compatible.