ThermoDrain TD 46% Efficiency – 4″ Commercial High-Flow Drain Water Heat Recovery, 42″ (TD442B)

Commercial High-Flow Drain Water Heat Recovery

The ThermoDrain™ TD442B is the 4″ high-flow model in the ThermoDrain line, built for larger drain stacks in commercial and high-demand residential applications. A single ¾″ copper potable-water coil is wound around a central 4″ copper drain tube: as warm wastewater flows down the stack, the coil captures the heat and preheats the cold water feeding your water heater and/or shower — recovering energy that would otherwise be lost down the drain.

Key Features

• 46% verified thermal efficiency at 9.5 L/min (2.5 GPM)
• 4″ drain diameter for high-flow stacks; 42″ length
• Single ¾″ coil design — very low pressure drop, no risk of coil blockage
• Choice of factory-installed ¾″ crimp PEX (CSA B137.5 / ASTM F1807) or expansion PEX (ASTM F1960) fittings
• All-copper construction; no moving parts, zero maintenance, 100% recyclable
• Compatible with all water heaters (tank, tankless, hybrid, solar)

Technical Specifications

• Efficiency (CSA B55.1 verified, 9.5 L/min): 46%
• Drain diameter: 4″ | Length: 42″ | ¾″ potable water connections
• Certifications: verified to CSA B55.1, certified to CSA B55.2
• 5-year warranty
• Note: drain couplings are not included with this unit

Installation

Installed vertically in the 4″ drain stack (horizontal installation possible with reduced efficiency). Preheated water can feed the water heater cold inlet, the shower cold side, or both for the maximum-efficiency configuration.