Chofu Wood Fired Water Heater

Installation

The Chofu wood fired hot tub heater will connect to any tub using accessories provided (see connection kit): flexible neoprene tubes, stainless steel pipes, and thru-wall tub ports. (Thickness of the tub wall must be specified to determine the length of thru-wall ports.)
Installation requires these four basic steps:

1. Preparing a brick or cement foundation next to the hot tub to receive the Chofu wood fired heater.
2. Cutting 1 7/8-inch holes in the side of the tub wall for thru-wall ports.
3. Installing pipes to connect heater and tub.
4. Installing the stove pipe, (8 feet recommended)

Operations

The Chofu hot tub heater operates like a conventional wood stove, achieving its fastest heating rate from dry hardwoods. It uses 17-inch wood with an 18-inch x 14-inch x 14-inch firebox. The most efficient heating comes from using 17-inch x 1 1/2-inch x 1 1/2-inch wood, loaded at 45 min. intervals.

The Chofu has a high and low speed draft control to regulate the heating rate. It operates with the draft wide open for fast heating, and closed down to maintain temperature once the water is hot.

Features

• High grade stainless steel stove body
• 1/8-inch steel stove front
• Heavy cast iron door and grates
• Hot Tub Connection kit (see photo)
• Generous size firebox, 18"L x 14"W x 10"H
• Vented smoke-outlet for secondary combustion.
• 3/4-inch drain for freeze protection.
• An ash drawer for easy removal of ashes.
• A long handled ash rake

Specifications

• Dimensions: 16" wide x 23" long x 18" high
• Weight: 59-lbs.
• Stove body: Grade 316 stainless steel, inner wall 20-gauge, outer wall 22-gauge
• Stove Front: 1/8-inch steel
• Firebox door and grates: cast iron
• Firebox dimensions: 18"L x 14"W x 10"H
• Heat exchange surface area: 9 sq. ft.
• Smoke outlet: 4 5/8-inch (reduced to 4-inch)
• Circulating pipes: 1 3/4-inch O.D.
• Drain: 3/4-inch I.D.
  

Heating

Although the heating rate is variable depending on dryness of wood, frequency of loading, etc., the average heat output of the Chofu CHS is 32,000 BTU’s. A 200-gallon tub can be heated at approx. 20ºF per hour.

Note: The heat output of the Chofu increases after an initial 45-min. warm-up period that heats the stove body and establishes a bed of coals.

Heating Schedule
55ºF to 105ºF

Filter System Option

The Chofu system will be attractive to customers who have limited electrical capacity at their cottage or would not frequent the hot tub on a daily basis (weekend use). As an option we offer a low voltage filter/pump system with a GFI receptacle. This system, with proper chemical maintenance, allows users to extend the clarity and "health" of the water allowing an extended time frame between draining of the tub.