RÉCUPÉRATION DE CHALEUR DES EAUX DE DRAIN PROJETS COMMERCIAUX, INDUSTRIELS ET INSTITUTIONNELS RÉALISÉS

Les bâtiments commerciaux et institutionnels sont généralement caractérisés par une utilisation fréquente et à volume élevé d'eau chaude qui est littéralement déversée dans les égouts. Le ThermoDrain est conçu pour récupérer cette énergie gaspillée et la retransférer directement dans votre système de chauffage d'eau potable, réduisant ainsi considérablement les coûts associés au chauffage de l'eau chaude. Notre échangeur de chaleur à double paroi est homologué pour une utilisation avec de l'eau potable.

Engineering Division • Commercial, Multi-Family & Industrial Systems

Commercial Drain-Water Heat Recovery (DWHR).
Thermodynamic Principles & P.Eng. Specification.

In high-density residential (MURB), institutional, and commercial operations, domestic water heating accounts for 25% to over 40% of aggregate building thermal energy demand. ThermoDrain® falling-film counterflow heat exchangers passively harvest sensible heat from vertical drainage stacks to preheat incoming municipal makeup water ahead of central boiler plants. With zero moving parts, zero electrical parasitic consumption, and verified CSA B55.1 ratings, ThermoDrain delivers rapid compliance margin for NECB, ASHRAE 90.1, BC Step Code, and CMHC MLI Select projects.

Submit Mechanical Drawings for Engineering Review Download MasterFormat 22 31 16 Guide Specs → Energy Modeling Spreadsheet (.xlsx)
< 2.5 psi (17.2 kPa)
Potable Head Loss @ 2.5 gpm (CSA B55.1)
46.2% – 59.1%
Certified 4" Heat Exchanger Effectiveness (ε)
CSA B55.1 / B55.2
Third-Party Tested • Vented Double-Wall Safety
6.5 – 9.0 kW
Thermal Peak Shaving / Active Shower Draw
Government Registry Listing & Third-Party Verification
Indexed on the Natural Resources Canada (NRCan) Searchable Product Registry Every commercial and residential ThermoDrain® unit is independently tested in accredited laboratories according to CSA B55.1 (thermal efficiency) and CSA B55.2 (structural and potable safety). Performance metrics are registered with Natural Resources Canada, providing verified empirical submittal data for HOT2000, EE4, and EnergyPlus building simulations.
Verify Official NRCan Registry →
Engineering Physics

Falling-Film Fluid Dynamics & Pressure Drop Control

Unlike active greywater systems requiring holding tanks, electric pumps, filters, and chemical treatment, ThermoDrain relies strictly on annular gravity flow and conductive copper heat exchange:

Annular Falling-Film Regime (DWV Column)

Vertical drainage entering the copper core forms a turbulent annular film approximately 0.04 to 0.06 in (1.0 to 1.5 mm) thick against the inner tube wall due to gravitational acceleration and surface tension.

  • Zero DWV Backpressure: The interior core remains entirely open to atmospheric venting. It causes no backpressure and requires no cleanout bypass.
  • Convective Boundary Layer: High film shear velocity creates convective heat transfer coefficients ($h$) exceeding 1,200 W/m²·K.
  • Non-Clogging & Self-Scouring: Grease, soap scum, lint, and hair cannot bridge the open 4-inch core diameter, eliminating operational fouling.

Counterflow Coil Hydraulics (Potable Feed)

Cold municipal water enters the bottom fitting and spirals upward through rectangular-profile copper coils mechanically wound under tension around the central drain tube.

  • True Counterflow Profile: Maximizes the Log Mean Temperature Difference (LMTD) by exposing the coldest incoming makeup water to the exiting drainage film.
  • Controlled Potable Head Loss: Hydro-formed internal coil geometry restricts total pressure drop to ≤ 2.5 psi (17.2 kPa) at rated fixture flow rates, protecting plumbing fixture pressure.
  • CSA B55.2 Vented Double Wall: Potable and drainage circuits are isolated by an engineered double wall with a vented capillary air gap open to atmosphere, satisfying North American plumbing codes.
Thermal Transfer Formulation (ε-NTU Method):
q = ṁ × c_p × (T_out - T_in) = ε × C_min × (T_drain,in - T_potable,in)

Where: ε = CSA B55.1 tested heat recovery effectiveness (0.462 to 0.591 for commercial 4" series); C_min = Minimum fluid thermal capacity rate ($ṁ \cdot c_p$); T_drain,in = Mixed shower effluent temperature entering stack (typically 38°C to 41°C / 100°F to 106°F); T_potable,in = Incoming municipal cold mains temperature (typically 4°C to 12°C / 40°F to 54°F).
Regulatory & Financial Drivers

Compliance Alignment with Model Energy Standards

Integrating DWHR into building schematics provides a high ratio of energy reduction per capital dollar invested, directly addressing current performance pathways:

CMHC MLI Select (Multi-Residential Housing)

Qualifies multi-residential developments (MURBs) for up to 100 energy points by reducing baseline energy consumption and GHG emissions by 20%, 25%, or 40% against model energy codes. Secures 50-year loan amortizations and reduced mortgage loan insurance premiums.

NECB, IECC C404 & ASHRAE 90.1 Compliance

Directly contributes to compliance under National Energy Code of Canada for Buildings (NECB Part 5), IECC Section C404, and ASHRAE Standard 90.1 (Service Water Heating). Mitigates the need for aggressive building envelope insulation additions or custom high-cost glazing assemblies.

BC Energy Step Code & Toronto Green Standard

Assists design teams in satisfying Thermal Energy Demand Intensity (TEDI) and Total Energy Use Intensity (TEUI) targets in upper Step Code tiers (Steps 3, 4, and 5) as well as Toronto Green Standard (TGS) Version 4 GHG targets for multi-family buildings.

CaGBC Zero Carbon Building Standard (ZCB) & LEED

Eliminates high-peak electrical demand on central heat pump water heaters (HPWH) during simultaneous shower events, minimizing backup electric resistance engagement and directly curbing building operational Scope 1 and Scope 2 carbon intensity.

Commercial Project Archetypes

Application Engineering & Operational Payback

Performance projections modeled across commercial utility averages ($0.14/kWh electric, $1.10/therm natural gas):

Building Typology Estimated Daily DHW Demand Recommended ThermoDrain Architecture Annual Thermal Energy Harvest Projected Simple Payback
Multi-Residential (100-Suite MURB) 16,000 – 22,000 L/day (4,200 – 5,800 gal/day) (5×) TD460 on vertical 4" DWV risers 150 – 210 GJ/year (142 – 199 MBtu) 2.0 to 3.2 Years
Full-Service Hotel (180 Guest Rooms) 22,000 – 32,000 L/day (5,800 – 8,500 gal/day) (8×) TD460 or TD472 on guest room stacks 270 – 380 GJ/year (256 – 360 MBtu) 1.6 to 2.4 Years
Municipal Aquatic & Community Center 12,000 – 18,000 L/day (clustered) (4×) TD460 manifolded in reverse-return 130 – 190 GJ/year (123 – 180 MBtu) 1.1 to 1.7 Years
Commercial Laundromat / Linen Facility 30,000 – 55,000 L/day (8,000 – 14,500 gal/day) Modular vertical parallel array (TD472 cores) 420 – 750 GJ/year (398 – 711 MBtu) 0.8 to 1.4 Years

Commercial 4-Inch Core Specifications (Series TD4)

Built with heavy-gauge copper DWV core tubes and high-pressure potable coils. Outer drain ends are sized for standard shielded mechanical couplings (No-Hub):

Model (SKU) Drain Diameter × Total Length Required Vertical Stack Clearance Potable Supply Ports Tested Efficiency (CSA B55.1) Certified Spec Sheet
TD442 4.0" × 42.0" (1067 mm) 46.0" (1168 mm) 3/4" Rigid Copper / NPT 46.20% TD442 Spec Sheet (PDF) →
TD460 4.0" × 60.0" (1524 mm) 64.0" (1625 mm) 3/4" Rigid Copper / NPT 55.30% TD460 Spec Sheet (PDF) →
TD472 4.0" × 72.0" (1828 mm) 76.0" (1930 mm) 3/4" Rigid Copper / NPT 59.10% TD472 Spec Sheet (PDF) →
Hydraulic Engineering Flexibility

Series Piping, Parallel Manifolds & Vertical Stacking

ThermoDrain units can be staged to match the specific pressure allowance and thermal lift requirements of the building:

Series Coil Piping Max ΔT Lift
Piping outer potable coils in series forces total makeup flow sequentially through each coil. This increases fluid velocity, pushes the flow regime deeper into the turbulent zone (higher Reynolds number), and maximizes the convective heat transfer coefficient ($h$) for higher outlet preheat temperatures. Best suited for standard 3/4" nominal flow rates with robust municipal supply pressure.
Parallel Manifolds (1" to 2"+ Mains) High Flow Capacity
Enables seamless connection to 1", 1-1/2", and 2" primary water service mains. By branching the main header into parallel 3/4" coil runs using reverse-return (Tichelmann) piping, the total flow volume is divided. This keeps potable velocity within standard engineering limits (5–8 ft/s) and maintains total loop pressure drop strictly ≤ 2.5 psi across flows from 8 to 40+ gpm.
Vertical Drain Stacking Extended Drop
Where vertical riser drops permit (e.g., parking garages, basements, or multi-story mechanical chases of 9 to 12 ft), two units can be stacked vertically on the same drainage stack with shielded couplings, effectively doubling annular film contact time without expanding the horizontal footprint.
Plumbing Code Precaution: Regardless of series or parallel orientation, preheated potable discharge must route exclusively to the primary water heaters or storage tanks. Preheating direct cold feeds to thermostatic mixing valves is strictly prohibited.

Commercial Procurement & Distribution

ThermoDrain® equipment is available via national wholesale supply contracts. Invoicing is conducted through existing mechanical contractor commercial trade accounts:

Groupe Deschênes • Wolseley Canada • EMCO Corporation • Noble • Desco • B.A. Robinson • Ferguson • Winsupply