Dickinson Radex Water Heat Exchanger

Turn Waste Heat into Cabin Warmth

Every water-cooled engine produces a significant amount of heat that is typically carried away and discarded through the cooling system. The Dickinson Radex water heat exchanger puts that energy to work. By connecting the Radex to your engine's coolant circuit or to a dedicated hot water boiler, you can redirect that thermal energy into a steady flow of warm, dry air throughout your cabin.

This approach to heating is both efficient and economical. You are not burning additional fuel to generate heat; you are simply recovering warmth that already exists as a byproduct of running your engine. The result is clean, comfortable cabin heat with no additional fuel consumption beyond what your engine already requires.

Two Models to Suit Your Space

The Radex is available in two configurations to match different heating requirements. The Radex 1 (00-RAD1) is the single-fan model, suited to smaller cabins or supplemental heating needs. The Radex 2 (00-RAD2) is the larger double-fan unit, capable of handling greater heating loads in more spacious interiors.

Both models share the same depth profile and height, making installation planning straightforward. The Radex 2 is simply wider to accommodate its second fan and larger heat exchanger coil, and it also includes a built-in manual air bleed valve to help prevent air locks when used with fresh water-cooled engines.

• Radex 1 (00-RAD1): 12,000 BTU/hr output, single fan, 0.74 amps at 12V
• Radex 2 (00-RAD2): 24,000 BTU/hr output, dual fan, 1.48 amps at 12V

Stainless Steel Construction for Marine Environments

Marine environments are demanding on any equipment, and heating systems are no exception. The Radex is built with stainless steel construction that minimises maintenance requirements and resists the corrosion that salt air and moisture can cause over time. This makes it a reliable long-term addition to a boat's heating system, requiring little attention once properly installed.

Simple Installation and Flexible Mounting Options

Installing the Radex requires connecting it to a circulating hot water source and wiring the fan or fans to a 12V supply. The copper tubing on the unit has an outside diameter of 3/4 inch (1.9 cm), and the manufacturer recommends using compression fittings with a 3/4-inch diameter female tube to a 5/8-inch diameter male hose barb fitting with a hose clamp when connecting heater hose. A 3-amp fuse is recommended in the electrical installation.

To ensure adequate airflow, the unit should be installed with at least 2 inches (5.08 cm) of airspace behind the fan. For fresh water-cooled engine installations, the heater should be mounted below the level of the radiator cap, or an air bleeder should be used to prevent trapped air locks.

Two mounting kit options are available separately. The side mount bracket kit (22-001) fits both the Radex 1 and Radex 2 and allows mounting to a floor, wall, or ceiling. The frame mount kits (22-002 for Radex 1, 22-003 for Radex 2) allow for a recessed flush installation into a bulkhead or cabinet with a trim panel for a clean, integrated finish.

Low-Amp Fan Operation with Individual Controls

Each fan in the Radex is a quiet, low-amp 12V unit designed to push air through the heated coil efficiently without placing a significant load on your vessel's electrical system. The Radex 1 draws just 0.74 amps, while the Radex 2 draws 1.48 amps total. Each fan is controlled by its own dedicated on/off switch, giving you straightforward control over airflow and heat output.

Versatile Applications Beyond the Boat

While the Radex is well suited to marine use, its design makes it equally practical in any setting where a source of circulating hot water and 12V power is available. RV owners, truck operators, and car enthusiasts have all found the Radex to be a reliable supplemental heating solution. Wherever an engine or hot water system is already running, the Radex can put that thermal energy to use.

Specifications

• Model (Single): Radex 1 - 00-RAD1
• Model (Double): Radex 2 - 00-RAD2
• Width - Radex 1: 10.38" / 26.37 cm
• Width - Radex 2: 16.88" / 42.88 cm
• Height - Both Models: 7.00" / 17.78 cm
• Depth - Both Models: 5.00" / 12.7 cm (8" with tubes)
• Weight - Radex 1: 6.5 lbs / 3 kg
• Weight - Radex 2: 9 lbs / 4 kg
• BTU Output - Radex 1: 12,000 BTU/hr / 3.5 kW (based on 100° temperature rise)
• BTU Output - Radex 2: 24,000 BTU/hr / 7 kW (based on 100° temperature rise)
• Operating Voltage: 12V DC
• Amp Draw - Radex 1: 0.74 A
• Amp Draw - Radex 2: 1.48 A
• Airflow - Radex 1: 100 CFM
• Airflow - Radex 2: 200 CFM
• Copper Tubing Outside Diameter: 3/4" (1.9 cm)
• Recommended Fuse: 3 A
• Minimum Airspace Behind Fan: 2" (5.08 cm)
• Construction Material: Stainless steel
• Warranty: 1-year limited warranty (original purchaser)

Key Features 

• Recovers engine waste heat: converts coolant thermal energy into cabin warmth without burning additional fuel
• Two model sizes available: choose the Radex 1 for smaller spaces or the Radex 2 for larger cabins requiring greater heat output
• Continuous heat supply: as long as the engine or hot water system is running, the Radex delivers a steady flow of tempered air
• Minimal electrical draw: low-amp fan operation places very little demand on your vessel's 12V electrical system
• Individual fan controls: each fan has its own on/off switch, giving you direct control over heat distribution
• Stainless steel construction: resists corrosion in salt air and marine environments, reducing long-term maintenance
• Flexible mounting options: compatible with side mount bracket or recessed frame mount kits for floor, wall, ceiling, or bulkhead installation
• Versatile installation: suitable for boats, RVs, trucks, and cars wherever circulating hot water and 12V power are available
• Radex 2 air bleed valve: built-in manual air bleed valve on the larger model helps prevent air locks in fresh water-cooled engine installations
• Dry, clean heat output: produces comfortable cabin warmth without combustion, fumes, or open flame inside the living space