This is the perfect hot tub system for cabins, those that are off grid, or if you're simply looking for something a
little more rustic or "back to basics". Like our regular complete hot tub systems, our wood fired hot tub systems can be in either
western red cedar,
Alaskan Yellow Cedar or
The Chofu is a precision built wood-burning water heater specifically designed for heating hot tubs.
It circulates water using the principal of thermosiphon (the movement created by rising hot water)and
eliminates the need for a circulating pump or electricity. This unique feature opens up a whole new
range of possibilities for alternative hot tubs. Now you can have a traditional wooden soaking hot tub
without the need for pumps or electricity.
The stove body of the Chofu is made with high quality #304 stainless steel and is intended to be used
outdoors. The firebox is also made of stainless steel and will withstand many years of
service without danger of burning-out. The smoke outlet on the Chofu features a unique vented collar that
provides secondary combustion of unburned gases. This secondary combustion reduces smoke emissions and
The Chofu utilizes a sophisticated heat exchange design for efficient water heating. The stainless steel
stove body surrounding the firebox is a double-walled water-jacket with a 1-inch space between. This makes
the entire firebox (except the front) a heat-transferring surface. Additional heat transfer takes place in a
water-filled baffle plate that runs horizontally through the firebox. The baffle deflects the path of the
fire, so it gives up more heat into the water jacket before going up the chimney.
The Chofu 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
Installation requires these four basic steps:
- Preparing a brick or cement foundation next to the hot tub to receive the Chofu heater.
- Cutting 2-1/2" holes in the side of the hot tub for thru-wall ports.
- Installing pipes to connect heater and tub.
- Installing the stove pipe (8 feet recommended).
Complete installation instructions can be seen here.
The Chofu operates like a conventional wood stove, achieving its fastest heating rate from dry hardwoods.
It uses wood up to 17" long and has an 18" x 14" x 14" firebox. The most efficient heating comes from using
17" x 1½" x 1½", loaded at 45 min. intervals.
The Chofu hot tub heater 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.
- High grade stainless steel stove body
- 1/8-inch steel stove front
- Heavy cast iron door and grates
- Hot Tub Connection kit
- Generous size firebox, 18"L x 14"W x 10"H
- Vented smoke-outlet for secondary combustion.
- ¾" drain for freeze protection.
- An ash drawer for easy removal of ashes.
- A long handled ash rake.
- 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: 1¾" O.D.
- Drain: ¾" I.D.
Heating Rate Information
Although the heating rate is variable depending on dryness and type of wood, frequency of loading, etc.,
the average heat output of the wood burning Chofu hot tub heater is 32,000 BTU’s (an 11kW electric heater
is about 30,000 BTU's). A 200 gallon hot 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.
|Hot tub size...
diameter x height
||temp. rise per hour
*We don't recommend this large a hot tub due to the extended heat-up time
Stainless Steel Stovepipe
Made of grade 304 stainless steel. 8ft of pipe is necessary to produce the
optimum air-draw through the stove for a fast, efficient heating rate; a shorter
length will produce a slower heating time. Using more than 8ft of pipe produces
a hotter fire but will reduce fuel efficiency because more of the flame is drawn
up into the chimney. Remedy this by installing a stove damper. If more than 8ft
of pipe is used, it must be supported to insure stability. Sheet metal screws
and a cobalt drill bit are provided with the Chofu Wood-fired Heater for
fastening stove pipe connections.
Stainless Steel Chimney Cap
Made of grade 304 stainless. Maybe necessary where danger of fire is extreme,
however, secondary combustion in Chofu prevents most sparks from escaping
chimney. Adding a chimney cap reduces draw through stove, slowing the heating
rate. 10ft or more of pipe is necessary when using a chimney cap, to maintain
maximum heat rate. Stovepipe with a chimney cap must always be supported to
Filtration / Circulation System
This high performance pump/filter skid pack is rated at 2400 gallons per hour and consists of an energy
efficient 120v Hayward Power-Flo pump and Micro Star-Clear fliter, all preplumbed and mounted to a molded base.
Designed for outdoor applications, simply plug it into a GFCI protected outlet and add a timer if desired.
Our More Popular Sized,
Wood Heated, Complete Hot Tub Systems
Includes 2 benches. Perfect for 2
||No bench. Up to 4 people sit on the floor.
||Includes full circle bench for up to 4 people.
|These are just some of the more common
sizes. Many other sizes, including custom sizes and individual hot tubs are avaialbale.
For a complete price list please see here.