THERMODRAIN MODEL SELECTION

Welcome to the ThermoDrain model selection guide. Below you will find information on how to select the right size model drain water heat recovery unit. This is the first step in saving energy, money and getting more out of your water heater.

DRAIN WATER HEAT RECOVERY RESIDENTIAL MODEL SELECTION GUIDE

Your model selection is quite simple. Three different factors will determine the model that is best for you. The first two are measurements of the drain diameter where the unit shall be installed, followed by the length. You will then need to find the size of your cold water feed line size to the water heater. The models listed in the table below are all designed for residential installation and shall installed on the vertical drain stack where at least one shower is draining into.

MEASURE THE DRAIN SIZE

ThermoDrain comes in 3″, 4″ or 6″ inner drain diameter. Begin by determining your drain size.

Measure and determine your drain diameter using this guide.

MEASURE THE LENGTH YOU CAN INSTALL

Measure the maximum vertical length where the ThermoDrain will be installed. Then subtract 2.5″ to allow for the installation of the drain couplings. For example: If you have 45″ of vertical pipe, you can install a 42.5″ long unit (45″-2.5″=42.5″).

Find the maximum length of drain water heat recovery for your application with this guide

SELECT YOUR MODEL

Using the table below, the drain measurement and the maximum length, you can either install the maximum size unit or anything below this size in length.

FIND COLD WATER CONNECTION SIZE
NOTE: THERMODRAIN HAS A 3/4″ CRIMP PEX OPTION

Standard size is 3/4″. ThermoDrain is available from 1/2″ to 1.5″+

LOOKING FOR METRIC SIZES?

Note: We do offer the ThermoDrain in metric sizes. 110 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.

LOOKING FOR A 2″ DRAIN DIAMETER?

Consider using a 3″ ThermoDrain on a 2″ drain stack if you have no other choice. Verify with local codes. Some areas will allow this due to the simple reason that no solids flow down a 2″ residential drain pipe. The Ontario Building Code 7.4.9.1 allows you to install a larger diameter ThermoDrain on a smaller diameter drain pipe and then return to a smaller diameter under these circumstances.

Drain water heat recovery

COMMON RESIDENTIAL MODELS

Model
Efficiency
Pressure Drop
Drain
Length
Fitting
Comment
TD336B
39.2%
1.3 Psi
3″
36″
3/4″
For Smaller Restricted Areas
TD342B
42.8%
1.6 Psi
3″
42″
3/4″
Perfect for Residential applications
TD348B
46.0%
1.8 Psi
3″
48″
3/4″
A higher performance, added value
TD360B
51.5%
2.3 Psi
3″
60″
3/4″
Multi-shower applications & higher efficiency homes
TD372B
55.6%
2.7 Psi
3″
72″
3/4″
Very high efficiency, Extremely high efficiency homes
TD442B
46.0%
1.4 Psi
4″
42″
3/4″
Perfect for residential applications. Excellent value
TD460B
57.3%
2.2 Psi
4″
60″
3/4″
Multi-shower applications & high efficency homes
TD472B
58.4%
2.7 Psi
4″
72″
3/4″
Very high efficiency. Extremely high efficiency homes

Most Popular Models

TD336B

Excellent value

3″ Drain Diameter, 36″ Long

39.2% Efficient @ 9.5 Lpm

1.3 Psi pressure Drop @ 9.5 Lpm

1425 kWh NRcan/Energuide credits

TD342B

Most common model used in residential applications

3″ Drain Diameter, 42″ Long

42.8% Efficient @ 9.5 Lpm

1.6 Psi pressure Drop @ 9.5 Lpm

1556 kWh NRcan/Energuide credits

TD348B

Designed for Higher Performance

3″ Drain Diameter, 48″ Long

46% Efficient @ 9.5 Lpm

1.8 Psi pressure Drop @ 9.5 Lpm

1673 kWh NRcan/Energuide credits