Contact Information:

Ralph Balltrip
Lexington, KY

(859) 299-2267

Cell Phone:
(859) 576-7621


Crown Royal RS 7200-7500

Greentech Manufacturing Inc. proudly presents the RS outdoor furnace series. Based out of International Falls, Minnesota, which is known as “The icebox of the nation”, we have been in business since the early 90’s. We are a family oriented business that started out by selling outdoor wood furnaces that were produced by different companies. Eventually we became highly unsatisfied with these furnaces and tried to get the manufactures to make changes. When these changes were not considered we decided to manufacture our own. We have been working to insure that our outdoor furnaces are of the best quality on the market and we strive to make improvements wherever possible. We believe that when you buy an outdoor furnace you are making an investment, not a purchase. This is why it has been our commitment to build the best performing and longest lasting furnace on the market. Every outdoor furnace we manufacture and sell comes with a Twenty Year Limited Workmanship Warranty as well as a Twenty Year Limited Corrosion Warranty. We are ready to meet your needs and provide you with outstanding service, that is our promise!


  • High Grade 409 Stainless Steel
  • Stainless steel heat transfer tubes 
  • Class A insulated chimney 
  • 4 models to choose from 
  • Fan forced draft 
  • •Smoke by pass 
  • 20 year limited warranty 
  • Safety latch firebox door 
  • Non-stick door gasket 
  • Insulation - Walls R30, Roof R40 
  • Shaker grate system with ash pan
  • Custom colors at additional cost


  • No splitting wood  
  • Outside, no mess in the house  
  • Works with any existing system  
  • No carbon monoxide caused by gas fumes  
  • Removable ash pan  
  • Large firebox & loading door  
  • Cost effective heat source  
  • Multiple 1 1/4” supply & return connections  
  • Easily removable rear access door to plumbing connections  
  • Light for night loading


  • Clean, Efficient & Safe  
  • Low maintenance  
  • Lower heat costs 
  • Warm & Dry floors  
  • UL 391, UL 726 & CSA B366.1


  • Commercial buildings  
  • Homes & Shops  
  • Greenhouses  
  • Swimming pools / Hot tubs  
  • Radiant in-floor heat  
  • Domestic hot water


MODELS RS 7200 RS 7300 RS 7400 RS 7500
Estimated Weight 1250 1500 2140 3230
Width 53" 53" 65" 83"
Length 55" 68" 83" 85"
Height 74" 74" 86" 101"
Max Firewood Length 32" 44" 56" 60"
Chimney Size 6" 6" 8" 10"
Door Size 20" x 20" 20" x 20" 24" x 24" 32" x 42"
Supply Size 2-1 1/4 2-1 1/4 2-1 1/4 4-1 1/4
Return Size 2-1 1/4 2-1 1/4 2-1 1/4 4-1 1/4
Water Capacity Approx 150 gals 200 gals 380 gals 620 gals
Fan Capacity 150 cfm 150 cfm 150 cfm 300 cfm
Turbo Draft B: 100 cfm 100 cfm 100 cfm 100 cfm
Approximate Sq. Ft. 2000-3000 4000-5000 8000-10,000 18,000-20,000
Approximate BTU's 165,000 240,000 365,000 500,000
Insulation: Walls R 30 R 30 R 30 R 30
Insulation: Roof R 40 R 40 R 40 R 40
Type 409 Stainless Yes Yes Yes Yes
Domestic Coil
250,000 BTU
Optional Optional Optional Optional
Domestic Coil
500,000 BTU
Optional Optional Optional Optional

Parts & Accessories

A Air Handler - Is a self contained forced air hot water heater. It can be easily installed in shops or garages and is thermostatically controlled for your complete heating needs.

B Stack Extension - This adds height to the stack for exhausting over buildings.

C Astro Foil - Installs easily and creates a superior thermal performance for in floor heat.

D Water Lines - Many brands of water lines are available; many of which have a thirty year warranty and are designed to take constant heat of hot water systems such as ours. It is easily formed and uses compression fittings for trouble free installation.

E Insulated Pipe - Insulated PVC is used in ground to run your water lines through. With this insulated pipe, there is very little heat loss in the ground.

F Tube & Shell Coil - This unit has been specially designed to be used for swimming pools and hot tubs.

G Chemical - This is low pressure boiler treatment for hard water. It is most effective at removing scale, inhibiting corrosion, and neutralizing acids.

H Circulating Pump - Is used to circulate water from the outdoor wood furnace to the house and back to the furnace. There are several models available to suit your specific installation.

I W.A. Heat Exchanger - A water to air heat exchanger may be installed into an existing electric or gas furnace duct work, therefore using the furnace blower to circulate the heat from the heat exchanger through the duct work of your building.

J Brazed Plate Heat Exchanger - These water to water heat exchangers make them ideal for domestic water heating, radiant floor, and hot water boilers.

K Brass Fittings - A large supply of brass fittings for all applications.

L Cloverleaf Rain Cap - Eliminates downdraft problems, creates better burns and keeps rain and snow out.

Financing Options Available


Zero interest, zero payments OR Straight Financing! Click here to find out more information. Applications can be processed on the internet or over the phone.