WindFurnace.com proposes an improved Wind Furnace (UMass circa 1972-1985) resulting in reduced cost and complexity of past wind driven heating systems.

WindFurnace.com is not based on electricity generation but converts rotational energy, from a wind turbine, directly into heat through use of a dynamic heat generator (DHG) manufactured by Island City Engineering of Merrill, Wisconsin. A DHG is a hydro-dynamic rotary device that creates heat through fluid shearing (Fig. 1). A DHG can convert rotation to heat at efficiency levels greater than 85%.

Vertical axis wind turbines are well suited for this application because they deliver high torque, self-start, and can be mounted on existing structures; such as roof tops and silos. The turbine drive shaft can be extended into an insulated space where the DHG would reside.

Temperatures can be precisely controlled such that heat transfer fluids can be heated to temperatures up to 600°F or water can be held below boiling and stored in plastic tanks, if desired.

Energy is stored in multiple insulated tanks that are heated sequentially (Fig 2). Separation valves between tanks allow each tank to be fully heated before the next tank volume is added. As each individual tank reaches its desired temperature, the next tank is brought in by opening a tank separation valve. Using multiple sequential tanks allows the system to maintain higher temperatures and allows the total tank volume to be optimized.

A pump in series with the DHG moves fluid through the system.

Current production DHGs operate between 1800 and 3000 rpm, however, Island City has designed a DHG specifically for wind turbine applications. The purpose built DHG would produce heat at low speeds thus eliminating the need for a gearbox.

Advantages:
• Power absorption of the DHG is greater than power produced from the wind turbine, thus, the turbine never over-speeds (Fig. 3).
• Heat can be stored for long periods at low cost.
• No high voltage interface with a utility.
• The purpose built DHG will eliminate the losses associated with transmissions.
• Energy converted directly to heat eliminates losses associated with conversion of rotational energy into electricity then electricity to heat.
• DHGs eliminate losses due to degradation of electric element heaters.
• The system is scalable from 5 to 1200 HP.
• The system can be built with mechanical thermostats that use zero electricity or designed with sophisticated electronic controls and displays.
• An electric motor with clutch can be installed with the DHG such that when wind speed is low and heat is required the DHG can continue to provide heat to the system by disconnecting the turbine and driving the system electrically. Motor power could come from batteries.
• WindFurnace.com adds value to structures such as silos and barns
Applications:
• Homes, farms
• Car washes
• Swimming pools
• Greenhouses
• Anaerobic digesters
• Industrial processes

A prototype system with gearbox and current production DHG has been built. Next step is to eliminate the transmission, install the wind DHG and source turbine.