FAQs

Warpfive Stove Fans are miniature Stirling engines.  They work by moving a sealed volume of air from the hot bottom plate to the cool top plate of the engine. As the air moves from the cool plate to the hot plate it is rapidly heated, it expands and pushes the piston up. As the air is moved from the hot plate to the cool plate it cools rapidly and contracts, this creates a vacuum which pulls the piston down. This same volume of air is rapidly heated and cooled many times per second. As the piston is connected to a crank shaft it causes the crank to rotate and this produces the mechanical power to rotate the propeller. 

You need to establish the temperature of your stove surface which can easily be done with a Stove Top Thermometer.  If you don’t have an accurate thermometer, place a drop of water on the surface – if it bubbles away instantly, you’ll know your surface is above 100 C (212 F).  The heat on your stove surface powers the engine which provides the energy to spin the propeller.   

The Warpfive Sidewinder Stove Fan is specifically designed to fit into most restricted spaces.  Its overall height is 225 mm (including the propeller)

The Warpfive Twinspeed Stove Fan is premium high performance engine with twin piston cylinders.  This makes it exceptionally powerful and able to move large volumes of air (in excess of 440 CFM), the perfect choice for a large room.

Stirling engines are incredibly reliable as they have no electrical components which can burn out.  We have test engines that run consistently – see here for more information 

Like any engine a Stirling engine requires basic care once every season or after approximately 1000 hours of use.  This entails wiping clean and lubricating the displacer shaft with the supplied lubricant.  Please see user guidelines for more information. 

It is important to use our supplied lubricant only because it is a synthetic, high temperature oil specially developed for use in extreme heat environments.  Using other oils such as mineral oil or light machine oil, will result in a sticky residue which will damage your engine’s performance.

It is likely that the squeaking is a result of the propeller hub touching the vertical upright.  Loosen the grub screw on the propeller hub and withdraw the propeller by 1 mm.  If the squeaking persists, hold the propeller by the hub and move the entire shaft back and forth, returning it to a central position.

Place the engine on top of your stove and allow a couple of minutes for the base to heat up.  Different engines have different operating temperatures.  Once the base of the engine has heated up sufficiently, gently spin the fan blades.  The fan will slowly start to rotate and gain speed.  The higher the temperature of the stove, the faster the fan will spin.  If the propeller does not spin, it is because your stove top is too cool. 

Yes you can so long as you spin the propeller as soon as it reaches operating temperature to keep the dust cover cool – it must not exceed 90°C (194°F).  Place the engine at least 150 mm (6 inches) away from the flue, however for hot fires in excess of 250°C (482°F), place the engine at least 200 mm (7.9 inches) away from the flue.

Yes a Stirling engine will work on any surface so long as there is sufficient heat transfer into the base of the engine.  All of our stove fans have minimum start up temperatures.  If the base of the engine reaches this minimum start up temperature it will work.  

No.  Operation is quiet – typically 36dB.  We use precision bearings and glass piston cylinders to ensure the engine will work quietly.

The higher the temperature of your stove surface, the faster your fan will spin.  When the room temperature is the same temperature as the air being moved by the propeller, it can be difficult to ascertain any movement.  Wet the back of your hand with cold water and hold it in front of the propeller – this will instantly give you some indication of air movement.  Warpfive propeller blades have been optimised to move maximum air at low RPM.

Yes. UPS is our carrier of choice and most shipments outside of the UK take between 5 to 7 days to be delivered.

Please return your engine to Warpfive, remembering to include your name and contact details. It is not necessary to return your propeller.

Please contact us for pricing.