• Kuuma Quality!!
    Great Customer Service...
    Great Customer Service...
    Great Customer Service...
  • Andy's Kuuma Sauna Stove
    Picture of a Kuuma Wood Sauna Stove with an
    outside feed, which really limits clean-up.
  • Proven Experience!!
    All of our products are manufactured indiviually
    with care.
    Over 30 + years of experience (Kuuma = Quality)...
  • Tim's Kuuma Sauna Stove
    Picture of a Kuuma Wood Sauna Stove
    with a glass window for romantic viewing.
    Visit our Facebook page for other custom set-up's!!
  • Manufacturing Process
    Picture of a Kuuma Wood Sauna Stove
    undergoing a few final touches.
  • Kuuma Vapor-Fire 100
    Picture of Kuuma Vapor-Fire bodies
    just before the painting process.
  • Custom Painting
    Picture of Billy Hiltunen Painting Kuuma
    Furnaces & Sauna Stoves.
  • Kuuma Electric
    Picture of our Kuuma Electric Sauna Stove,
    available in either a Floor or Wall Mount Model.
    Get off the top bench!!
  • Kuuma 24 Volt Computer
    High Efficiency & Low Emmissions...
    How? With our revolutionary
    24 volt Kuuma Vapor-Fire computer.
  • Kuuma Wood
    Picture of Kuuma Wood Sauna Stove bodies
    just before the painting process.
    Get off the top bench!!

Common Question's and Answer's about the Kuuma Vapor-Fire 100 Wood Furnace...

Any particular reason you are not EPA certified?

Here is where many people are very confused. Right now under Phase I there is not even a standard set yet for Indoor Forced Air Wood Furnaces in the U.S., and from talking to a few insiders with knowledge in the area Phase II (tougher standard) EPA certification probably won't be required until 2014. Also it probably won't be an efficiency testing but rather an emissions test, because if your emissions are low your efficiency will be good. We hear it will probably require less than 5 grams of emissions per hour because if it goes any lower than that the majority of companies won't have the means, time, or ability to adhere and be forced to quit manufacturing their furnaces and in turn put them out of business. The Kuuma Vapor-Fire furnace line has been my career project for the past 30 years which includes thousands upon thousands of test burns and many design changes. With endless and I do mean endless work hours we were able to achieve less than 1 gram of emissions per hour which is unheard of.

Here is how we began our certification/testing process. In 2009 the opportunity evolved to offer the tax credit with efficiency certification so we decided to take use Intertek (Who runs 3 of the 7 approved efficiency testing sites in the country) and it's testing facility in Madison, WI. Once we received the great efficiency results we were asked if we would also like to have the emissions tested so we would have the information ahead of time for any changes that we would need to make or potential advertising we would like to do. Being a smaller company with limited means this was not an easy decision to make, because the cost is substantial. However we knew that in order to survive and reach our goal of manufacturing the most efficient indoor wood furnace in the world and a truly green product we needed documented proof. This documented proof is located on our website where a PDF of the test results can be found.

Rest assured that when the opportunity becomes available for Phase II EPA certification we will be first in line. On a side note we have received recent calls from some of our competitors many of which, will have a lot of work to do by 2014, inquiring about the emissions testing process that we underwent.

What is the impact on total wood consumption per year if you use a super efficient furnace like our Kuuma Vapor-Fire?

Here are the important numbers that need to be examined: 1 gal. #2 fuel oil = 140,000 BTUs; 1 gal. propane - 91,500 BTU's; 1 cord paper birch wood = 21 M BTU's; 1 cord red oak = 25 M BTU's.

KuumaVapor-Fire furnaces were tested to have an overall efficiency as high as 85%, 99.4% combustion efficiency, less than 1 gr/hr of emissions, 99% "Smokeless" burn cycles, internal flue temperatures 285-400 degrees F., and external flue temperatures 150-250 degrees F. Kuuma Vapor-Fire furnaces have been used for over 25 years with no condensation issues whatsoever, because the flue temperatures are still high enough to support a natural draft system when installed according to our written directions.

A good estimate for oil usage for a heating season would be 500-1,000 gal., with lots of variables. We'll take a look at an average home using 750 gal. of oil for the heating season. 750 gal = 105 M BTU's. If a wood furnace was 100% overall efficient, which is not possible, it would take : 105 M BTU's /21M=5 cords of birch or 105 BTU's/25M=4.2 cords of oak.

Our KuumaVapor-Fire furnace at 82% average overall efficiency would be; 105 M BTU's/(21Mx82%) = 6.09 cords of birch or 105 M BTU's/(25 M x 82%) = 5.12 cords of oak.

Most manufacturers struggle to hit 60% overall efficiency, but we'll look at their results based on 60%. 105 M BTU's/(21M x 60%) = 8.33 cords of birch or 105 M BTU's/ (25M x 60%) = 7 cords of oak.

Therefore, using our efficient Vapor-Fire furnaces will, without a doubt, use less wood to deliver the same amount of BTU's you'd require in oil or propane for the heating season then a less efficient furnace would. The other big advantages are minimal air pollution, longer more even burns, and minimal creosote accumulation from 99% "Smokeless" burn cycles. The safely aspect is also huge in saving homes and lives.

I'm quite sure alot of manufacturers will be very surprised to see their furnace test results when regulations come into effect in 2013-14. They're not going to believe how much air pollution and wasted wood their so called efficient furnaces have produced. Many manufacturers will have to fold or redesign their furnaces quickly. I'm thankful that I invested the time, effort and money in preliminary testing so that our company is prepared for the future. We knew the regulations were forthcoming.

What I need to know about BTU ratings?

A lot of people are mixed up on the BTU's required to heat a home because oil and gas furnaces do no run steady hour after hour. If they did you'd spend $20,000/yr. to heat a home. As it is some people are spending over $4000/yr. to heat their homes. They cycle on and off. Your BTU needs are delivered intermittently. If your home is poorly insulated, or if for some reason you let it cool down, your oil and gas furnace would then run steady. Generally, a furnace rated at 100,000 BTU/hr. runs from 1/4 to 1/3 of an hour on the coldest of MN. days delivering about 30 to 40,000 BTU's/hr. to maintain a comfortable heat level for your home, i.e. 70 degrees F. Most people feel cool in their homes in between the on and off cycles of the oil and gas furnaces, therefore many people prefer wood heat because it's continuous.

Now, heating a home with our KuumaVapor-Fire furnaces is really special because they deliver very even continuous heat hour after hour. They don't smolder the wood and then blast the wood (the two extremes) like other wood furnaces. Instead, its unique automatic draft system avoids these extremes with a continuous front to back burn pattern that allows the user to adjust the burn rate, which in turn varies the BTU output. In mild weather you use a low setting for 15-25,000 BTU's/hr., in moderate weather a medium setting for 25-45,000 BTU's/hr., and in cold weather a high setting for 45-60,000 BTU's / hr. It adjusts simply by turning the knob on the computer from low to high and anywhere in between. Most people never go above the medium setting all winter long.

Keep in mind that all wood has the same # of BTU's pound for pound. The heavier more dense wood (oak, hickory, maple) have more available BTU's/piece than the lighter less dense wood such as poplar and pine, only because each piece weighs more. Every pound of wood that is 100% dry has approximately 8,600 BTU's /pound. Say for instance your home needed 100,000 BTU's/hr. to heat, it would take 11.6 pounds/hr. of 100% dry wood to heat it. Now, if your wood has a 20% moisture content, each pound of wood has only 6,880 BTU's in it (it's 8600 x .80). Then if your wood furnace is only 60% overall efficient, your BTU's would only be 4,128 BTU's/pound (that's 6,880x.60). This would result in a ridiculous amount of wood, 24.2 pounds/hr., to get the needed 100,000 BTU's/hr. In a 24 hr. period that would mean 576 pounds of wood needed for 100,000 BTU's/hr after hr. This would result in probably more than 20 cords of wood to heat your home for one winter. It makes more sense to say that most homes in the coldest of weather only use the 30-40,000 BTU's/hr and probably use 7-10 cords of wood/season to heat their homes. With our KuumaVapor-Fire furnaces that are 85% overall efficient and 99% combustion efficient most people use only 3-5 cords of wood to heat their home/season and that's what makes our furnace very special. To top if off we also have the clean burn of less than 1 gr. emissions/hr.

Does the Kuuma Vapor-Fire 100 have an automatic damper?

Yes, a 24 volt computer controls a 24 volt (step) motor for your primary intake air used in combustion.

Does the Kuuma Vapor-Fire 100 have a secondary chamber for the wood gases to burn?

Yes, right in and around the top of the fire chamber gasification takes place, in a ceramic lined area with secondary air present.

Does the automatic damper operate by a remote thermostat?

No, the adjustment is right on the computer itself. You just turn the knob to adjust (mild weather=lower and cold weather=higher). It makes it simple to operate.

What type of a blower system is used to deliver heat?

It has a two speed blower that is controlled by a remote thermostat. The blower system is activated by the low limit button thermostat that adjusts 90-130 degrees F. for the on temperature. Once it activates, your remote thermostat will determine if it needs high speed (calling for more heat) or low speed (room temp is satisfied.) The high speed is approximately 1500 cfm and the low speed is approximately 500 cfm, depending on the system back pressure. Therefore, the computer setting and the 2 speed blower help you to maintain your desired level of heat.

Is the fire box brick lined?

Yes, it's not only brick lined right to the ceiling, but ceramic lined behind the brick. All the internal parts are stainless steel and replaceable (ceiling, back, brick holders & straps, front). It's a life time furnace design.

What is the size bonnet is needed?

The opening for the bonnet is 2'x2' & 2'x2' for the return air. The bonnet height should be approximately 2 feet. Your heat output duct should be at least 180-200 square inches to prevent excessive back pressure.

What is the size filter does it take?

It takes two 14x24x1 filters.

Will the furnace heat during power outages?

Yes, when the power stops the blower and computer both shut down. The computer closes to its pilot air opening, causing the fire to slowly die down. You should open all heat ducts, remove the air filters, and rely on gravity air flow then. The front lift off hood can also be removed easily to allow additional heat to escape from the air jacket during power outages. A back-up generator or a 24 volt ac source would be handy.

What length of wood is best and how large a diameter should they be before they should be split?

The best length is 20". If they're smaller pieces (4" or less in diameter) they can be left round or un-split, but if they're larger they need to be split so they will dry better (5-8" in diameter).

Safety Features?

It has an insulated air jacket for 6" clearances. Low flue temperatures and very complete combustion add to safety. The 24 volt computer is set to keep the fire from under burning (causing creosote) or over burning (causing fire chamber damage). The 24 volt computer has an alarm that goes off if the furnace ever over heats (ashpan or main door left ajar). It has a high limit bonnet sensor that causes the blower high speed to activate irregardless of your remote thermostat and will also shut the computer off if the temperature continues to rise to 250 degrees F.

What size home will it heat?

It will heat approximately 3,500 square feet. If the home is properly insulated.

How does the burning of fire wood compare to other fuel costs?

"I have a 3200 square foot home and usually buy 5 cords of birch and maple wood a year. The cost is $75 - $100 per logger's cord and I cut and split it myself. My total cost then is about $500 per year or less and this is approximately 1/4 to 1/3 the cost of using another fuel such as gas, oil or electricity. The heat is much more constant using wood, that's why I like it. Our backup heat is electric baseboard." says Lamppa Manufacturing Owner Daryl Lamppa

What is the white exhaust you see coming from your chimney?

The exhaust you see when the temperature is 32 degrees F. or less, is actually water vapor condensing to form steam. The two byproducts of complete combustion are water vapor and carbon dioxide. If the outside temperature is above 32 degrees F., no visible exhaust occurs when complete combustion is taking place.

How often do I clean the furnace?

Once a year I use a rake that comes with the furnace to scrape out the heat exchanger. I proceed to vacuum through the clean out cover. Finally, I take the pipes off the back and blow them out outside. I've run this furnace for 28 years and never clean out the chimney as a matter of fact I don't even own a chimney brush (NO SMOKE=NO CREOSOTE).

Image of the Kuuma Vapor-Fire 100 freshly painted at the shop.

Common Question's and Answer's about the Kuuma VaporFire 200 Wood Furnace...

Any particular reason you are not EPA certified?

Here is where many people are very confused. Right now under Phase I there is not even a standard set yet for Indoor Forced Air Wood Furnaces in the U.S., and from talking to a few insiders with knowledge in the area Phase II (tougher standard) EPA certification probably won't be required until 2014. Also it probably won't be an efficiency testing but rather an emissions test, because if your emissions are low your efficiency will be good. We hear it will probably require less than 5 grams of emissions per hour because if it goes any lower than that the majority of companies won't have the means, time, or ability to adhere and be forced to quit manufacturing their furnaces and in turn put them out of business. The Kuuma Vapor-Fire furnace line has been my career project for the past 30 years which includes thousands upon thousands of test burns and many design changes. With endless and I do mean endless work hours we were able to achieve less than 1 gram of emissions per hour which is unheard of.

Here is how we began our certification/testing process. In 2009 the opportunity evolved to offer the tax credit with efficiency certification so we decided to take use Intertek (Who runs 3 of the 7 approved efficiency testing sites in the country) and it's testing facility in Madison, WI. Once we received the great efficiency results we were asked if we would also like to have the emissions tested so we would have the information ahead of time for any changes that we would need to make or potential advertising we would like to do. Being a smaller company with limited means this was not an easy decision to make, because the cost is substantial. However we knew that in order to survive and reach our goal of manufacturing the most efficient indoor wood furnace in the world and a truly green product we needed documented proof. This documented proof is located on our website where a PDF of the test results can be found.

Rest assured that when the opportunity becomes available for Phase II EPA certification we will be first in line. On a side note we have received recent calls from some of our competitors many of which, will have a lot of work to do by 2014, inquiring about the emissions testing process that we underwent.

What is the impact on total wood consumption per year if you use a super efficient furnace like our Kuuma Vapor-Fire?

Here are the important numbers that need to be examined: 1 gal. #2 fuel oil = 140,000 BTUs; 1 gal. propane - 91,500 BTU's; 1 cord paper birch wood = 21 M BTU's; 1 cord red oak = 25 M BTU's.

KuumaVapor-Fire furnaces were tested to have an overall efficiency as high as 85%, 99.4% combustion efficiency, less than 1 gr/hr of emissions, 99% "Smokeless" burn cycles, internal flue temperatures 285-400 degrees F., and external flue temperatures 150-250 degrees F. Kuuma Vapor-Fire furnaces have been used for over 25 years with no condensation issues whatsoever, because the flue temperatures are still high enough to support a natural draft system when installed according to our written directions.

A good estimate for oil usage for a heating season would be 500-1,000 gal., with lots of variables. We'll take a look at an average home using 750 gal. of oil for the heating season. 750 gal = 105 M BTU's. If a wood furnace was 100% overall efficient, which is not possible, it would take : 105 M BTU's /21M=5 cords of birch or 105 BTU's/25M=4.2 cords of oak.

Our KuumaVapor-Fire furnace at 82% average overall efficiency would be; 105 M BTU's/(21Mx82%) = 6.09 cords of birch or 105 M BTU's/(25 M x 82%) = 5.12 cords of oak.

Most manufacturers struggle to hit 60% overall efficiency, but we'll look at their results based on 60%. 105 M BTU's/(21M x 60%) = 8.33 cords of birch or 105 M BTU's/ (25M x 60%) = 7 cords of oak.

Therefore, using our efficient Vapor-Fire furnaces will, without a doubt, use less wood to deliver the same amount of BTU's you'd require in oil or propane for the heating season then a less efficient furnace would. The other big advantages are minimal air pollution, longer more even burns, and minimal creosote accumulation from 99% "Smokeless" burn cycles. The safely aspect is also huge in saving homes and lives.

I'm quite sure alot of manufacturers will be very surprised to see their furnace test results when regulations come into effect in 2013-14. They're not going to believe how much air pollution and wasted wood their so called efficient furnaces have produced. Many manufacturers will have to fold or redesign their furnaces quickly. I'm thankful that I invested the time, effort and money in preliminary testing so that our company is prepared for the future. We knew the regulations were forthcoming.

What I need to know about BTU ratings?

A lot of people are mixed up on the BTU's required to heat a home because oil and gas furnaces do no run steady hour after hour. If they did you'd spend $20,000/yr. to heat a home. As it is some people are spending over $4000/yr. to heat their homes. They cycle on and off. Your BTU needs are delivered intermittently. If your home is poorly insulated, or if for some reason you let it cool down, your oil and gas furnace would then run steady. Generally, a furnace rated at 100,000 BTU/hr. runs from 1/4 to 1/3 of an hour on the coldest of MN. days delivering about 30 to 40,000 BTU's/hr. to maintain a comfortable heat level for your home, i.e. 70 degrees F. Most people feel cool in their homes in between the on and off cycles of the oil and gas furnaces, therefore many people prefer wood heat because it's continuous.

Now, heating a home with our KuumaVapor-Fire furnaces is really special because they deliver very even continuous heat hour after hour. They don't smolder the wood and then blast the wood (the two extremes) like other wood furnaces. Instead, its unique automatic draft system avoids these extremes with a continuous front to back burn pattern that allows the user to adjust the burn rate, which in turn varies the BTU output. In mild weather you use a low setting for 15-25,000 BTU's/hr., in moderate weather a medium setting for 25-45,000 BTU's/hr., and in cold weather a high setting for 45-60,000 BTU's / hr. It adjusts simply by turning the knob on the computer from low to high and anywhere in between. Most people never go above the medium setting all winter long.

Keep in mind that all wood has the same # of BTU's pound for pound. The heavier more dense wood (oak, hickory, maple) have more available BTU's/piece than the lighter less dense wood such as poplar and pine, only because each piece weighs more. Every pound of wood that is 100% dry has approximately 8,600 BTU's /pound. Say for instance your home needed 100,000 BTU's/hr. to heat, it would take 11.6 pounds/hr. of 100% dry wood to heat it. Now, if your wood has a 20% moisture content, each pound of wood has only 6,880 BTU's in it (it's 8600 x .80). Then if your wood furnace is only 60% overall efficient, your BTU's would only be 4,128 BTU's/pound (that's 6,880x.60). This would result in a ridiculous amount of wood, 24.2 pounds/hr., to get the needed 100,000 BTU's/hr. In a 24 hr. period that would mean 576 pounds of wood needed for 100,000 BTU's/hr after hr. This would result in probably more than 20 cords of wood to heat your home for one winter. It makes more sense to say that most homes in the coldest of weather only use the 30-40,000 BTU's/hr and probably use 7-10 cords of wood/season to heat their homes. With our KuumaVapor-Fire furnaces that are 85% overall efficient and 99% combustion efficient most people use only 3-5 cords of wood to heat their home/season and that's what makes our furnace very special. To top if off we also have the clean burn of less than 1 gr. emissions/hr.

Does the Kuuma Vapor-Fire 200 have an automatic damper?

Yes, a 24 volt computer controls a 24 volt (step) motor for your primary intake air used in combustion.

Does the Vapor-Fire 200 have a secondary chamber for the wood gases to burn?

Yes, right in and around the top of the fire chamber gasification takes place, in a ceramic lined area with secondary air present.

Does the automatic damper operate by a remote thermostat?

No, the adjustment is right on the computer itself. You just turn the knob to adjust (mild weather=lower and cold weather=higher). It makes it simple to operate.

What type of a blower system is used to deliver heat?

It has a one speed blower of approximately 448 cfm and is activated by a snap disc button thermostat, located in the air jacket. You can adjust the on temp of the thermostat from 90-130 degrees F.

Is the fire box brick lined?

Yes, it's not only brick lined right to the ceiling, but ceramic lined behind the brick. All the internal parts are stainless steel and replaceable (ceiling, back, brick holders & straps, front). It's a life time furnace design.

What is the size of the heat outlet?

It has an 8" round heat outlet that you connect to the hot air bonnet of your existing furnace or directly into your ductwork.

What is the size of the filter used in the filter box?

It is 14x20x1.

Will the furnace heat during power outages?

Yes, when the power stops the blower and computer both shut down. The computer closes to its pilot air opening, causing the fire to slowly die down. You should open all heat ducts, remove the air filters, and rely on gravity air flow then. The front lift off hood can also be removed easily to allow additional heat to escape from the air jacket during power outages. A back-up generator or a 24 volt ac source would be handy.

What length of wood is best and how large a diameter should they be before they should be split?

The best length is 16". If they're smaller (4" in diameter or less) they can be left round, but if they're larger they need to be split so they'll dry better (5-8").

Safety Features?

It has 12" clearances, low flue temps and very complete combustion meaning added safety. The 24 volt computer is set to keep the fire from underburning (causing creosote) or overburning (causing fire chamber damage). The 24 volt computer also has a safety buzzer to signify any overheating which may be caused if the ashpan or fire door is ajar.

What size home will it heat?

It will heat approximately 3,000 square feet. If the home is properly insulated.

How does the burning of firewood compare to other fuel costs?

"I have a 3200 square foot home and usually buy 5 cords of birch and maple wood a year. The cost is $75 - $100 per logger's cord and I cut and split it myself. My total cost then is about $500 per year or less and this is approximately 1/4 to 1/3 the cost of using another fuel such as gas, oil or electricity. The heat is much more constant using wood, that's why I like it. Our backup heat is electric baseboard." says Lamppa Manufacturing Owner Daryl Lamppa

What is the white exhaust you see coming from your chimney?

The exhaust you see when the temperature is 32 degrees F. or less, is actually water vapor condensing to form steam. The two byproducts of complete combustion are water vapor and carbon dioxide. If the outside temperature is above 32 degrees F., no visible exhaust occurs when complete combustion is taking place.

How often do I clean the furnace?

Once a year I use a rake that comes with the furnace to scrape out the heat exchanger. I proceed to vacuum through the clean out cover. Finally, I take the pipes off the back and blow them out outside. I've run this furnace for 28 years and never clean out the chimney as a matter of fact I don't even own a chimney brush (NO SMOKE=NO CREOSOTE).

Image of the Kuuma Vapor-Fire 200 freshly painted at the shop.

Common Question's and Answer's about the Kuuma Woodburning Sauna Stove...

Is the metal heavy enough to prevent warpage?

Yes, it's constructed of 1/4", 3/8", and 1/2" plate.

Is it brick lined and baffled?

Yes, it's brick lined to also prevent warpage, and coupled with the baffle, enhances the burning of gases.

Is it an air tight stove?

Yes, the only air it gets is what you set on the carburetor. The doors are sealed for air tightness.

Can you heat water for bathing at the same time it heats the room?

Yes, with the optional 12 or 16 gallon stainless steel hot water tank water heats very quickly.

Can you see the fire?

Yes, if ordered, an optional 5" by 8" glass window is available to watch the burn and make your sauna experience even more romantic and enjoyable.

What size room will it heat?

Usually the small stove is for up to an 8x8x8 room. The medium is for up to 10x10x8, and the large is for rooms bigger than 10x10x8.

What length wood works best for each sauna stove?

16" wood lengths for the small and medium sauna stoves. 20" wood lengths for the large sauna stove.

Can you load wood from outside or from the dressing room?

Yes, the 8" or 12" optional extensions are used to go through the wall.

Image of the Kuuma Wood Sauna Stove in the finishing stages before paint.

Common Question's and Answer's about the Kuuma Electric Sauna Stove...

Is it costly to operate?

No, the floor and wall mount models are both 6,000 Watts, so you multiply 6x the rate to give you the cost per hour. If it costs you 5 cents per kilowatt it would be 6x5 cents or 30 cents per hour. (Not Very Expensive)

Do you need a rail around the heater?

No, they have insulated and double air flow hoods to keep them relatively cool on the outside, 6" clearance on the floor model and 1" clearance on the wall mount.

What size room is suited for the wall mount?

If insulated correctly, up to a 7x7x8 room.

What size room is suited for the floor model?

If insulated correctly, up to a 10x10x8 room.

Does it have a remote timer?

Yes, if ordered, an optional 1 hour or 6 hour timer can be located outside of the sauna room.

What is the best type of rock to use?

Granite rock is the best. The size of your fist or smaller are preferred.

Image of our Kuuma Electric Sauna Heater display at the shop.



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