Heat–powered stove-top fans have been around for a while, sitting atop solid fuel boat stoves all over the network. Employing a principal rediscovered by a gentleman called Thomas Seebeck back in 1821 they require no power to run, instead the difference in temperature between the hot base and the cooler radiating fins generates a small voltage, which drives a motor fitted with fan blades. Especially useful in narrowboats with stoves at the front of the saloon, the fan moves a small but significant amount of warm air down the boat.
But there is a major drawback in their use in boats that cruise. Inevitably, due either to the helmsman’s inattention, inconsiderate wind or inconvenient cross-currents, the boat is going to come in contact with parts of the stationary scenery. If the bump is heavy enough, the fan falls off, causing bent fan blades and possibly a bent frame as well.
A company called Valiant has recognised this problem, and have come up with a design that attaches to the stove’s flue pipe. This is the Remora Magnetic Flue Pipe Fan. We were asked to try one out and write a review.
It came well packed, with formed polystyrene packing protecting the contents. A pity that it wasn’t packed in compressed cardboard instead though, that would have enhanced the company’s eco-friendly image. The four-blade fan comes packed separately, but an Allen key and spare grub screw are provided to fit it.
What makes this stove fan different from others on the market is the magnetic “wings” that attach to the flue pipe above the stove top.
I was frankly a bit dubious about the effectiveness of this mounting method, but was surprised at how well the magnets hold the unit onto the flue. Time will tell if they remain as tenacious.
They should do, they're made from Samarium Cobalt, one of the strongest magnets available, and the one best suited to high temperature applications.
Within a minute of it being fitted it was off, the fan revolving quickly enough to produce a significant airflow close to the unit. And it was silent, always a good thing.
I experimented with different mounting heights, but found around 300mm above the stove top to be about the best. The flue pipe is hot enough at this level to run the motor, and it also leaves the stove top clear for the kettle and a pan of stew to simmer away.
One thing different from a stove-top fan is the response to varying states of the fire in the stove. With it drawing the fan runs quickly, slowing down as the fire dies down and the flue cools. In fact with the stove banked down overnight it stopped completely. But with the fire riddled and fresh fuel added it soon got going again.
A free-standing fan has a larger base area to absorb the heat, and the top plate of the stove is a lot thicker than the flue pipe, so holds heat for longer. So the fan reaction to a cooling fire is a lot slower. Having said that the four-blade fan on the Remora shifts an awful lot of warm air down the boat, a lot more than our old two-blade Eco-Fan.
The unit looks well put together and is covered by a 24 month warranty. The manufacturer also offers a maintenance and repair service to refurbish worn out parts. Hopefully several years down the line…
It’s not the cheapest of it’s kind on the market, stove-top fans are available for less than £30 now. But the Remora does what it’s supposed to do with no fuss, and it’s not going to finish up on the deck if we have a knock or two while locking.
There’s just one fly in the ointment. The recent upgrades to the Boat Safety Scheme recommend that boat stove flue pipes be insulated for safety and to improve efficiency. And the Remora relies on a hot flue pipe to work. It is only a recommendation, however, and I suspect the vast majority of flue pipes on boats are, like ours, uninsulated.
I must point out that we have no connection to Valiant, only that I was asked to try out and review the Remora. I hope I’ve done so fairly and impartially.