How quiet GMT? At 600mm a cooker hood might make sense. The motors in them have multiple windings, so when you select speeds, it's like swapping motors. Not slowing one down with power regulation.
Power regulation is usually a problem. It's only really variac's that can lower the voltage. Other methods cycle the power rapidly, which causes torque spikes and thus physical vibration. Even the variac has issues, in that it's still 50hz, but the fan isn't running at a multiple of 50 any longer. So it's applying power at the wrong time. Another vibration problem. The EC motor controller generally alters frequency to change speed. With the power disconnected before it rises on each and every pulse. The variac has no current limiting, so just can't compare, although is quite good still.
I really would look at hoods if you can find one in the small adds. It's a 100mm rvk with speed adjustment. In a box to further dampen the noise. Just chuck it on the roof. It will suck the walls in if asked to.
I don't tend to rely on the tent flaps. I like to find a sock, and use a bit of duct as a light trap. Knowing where the air enters, gives the opportunity to direct it through the tent.
At 40db and 250 cubic thingies, this 25w fan shifts some air, if in free space. £20 https://www.screwfix.com/p/manrose-x...ite-240v/11640
I reckon at half the volume (not to our ear, but how it carries) this 65 cubics 14w would probably do at £17 https://www.screwfix.com/p/xpelair-v...ite-240v/9931r
The cheap ass option is £12 for a similar 85 cubics, but is the loudest of all three https://www.screwfix.com/p/manrose-x...ite-240v/11097
Problem is, they are all about as perky as a desk fan. Designed to work with a bit of resistance, like in a bathroom with the door closed. Your exact situation is hard to judge. Non are wired yet either.
I did once buy a mixed flow (TT) fan, thinking it couldn't be that bad. An eBay item, for about £20. It sucked so bad, I gave it the local shop so they could save others from making the same mistake.
You could probably go with the £17 fan, knowing you could add another at the air-in point. The pair will do a cubic meter a minute. If you needed a pair. Or, if quite poor, you could move the 17£ to inlet duty and put the 20£ on the roof. It's not exactly quiet, like the boxed in rvk of a cooker hood though.
I have no doubt I would be looking in the small adds for a cooker hood. Nothing else is actually worth messing about with. If you can find a neff they are great. The rotating mass is balanced individually and the very best motors used. Women want a new kitchen every week, so £20 is all you need spend. You are familiar with the noise of them, and bathroom fans.
I blow smoke at my 25w bathroom fan, and it just hangs around. The thing struggles to open it's own shutters. There is only so much corner cutting you can do, before it just doesn't work.
Power regulation is usually a problem. It's only really variac's that can lower the voltage. Other methods cycle the power rapidly, which causes torque spikes and thus physical vibration. Even the variac has issues, in that it's still 50hz, but the fan isn't running at a multiple of 50 any longer. So it's applying power at the wrong time. Another vibration problem. The EC motor controller generally alters frequency to change speed. With the power disconnected before it rises on each and every pulse. The variac has no current limiting, so just can't compare, although is quite good still.
I really would look at hoods if you can find one in the small adds. It's a 100mm rvk with speed adjustment. In a box to further dampen the noise. Just chuck it on the roof. It will suck the walls in if asked to.
I don't tend to rely on the tent flaps. I like to find a sock, and use a bit of duct as a light trap. Knowing where the air enters, gives the opportunity to direct it through the tent.
At 40db and 250 cubic thingies, this 25w fan shifts some air, if in free space. £20 https://www.screwfix.com/p/manrose-x...ite-240v/11640
I reckon at half the volume (not to our ear, but how it carries) this 65 cubics 14w would probably do at £17 https://www.screwfix.com/p/xpelair-v...ite-240v/9931r
The cheap ass option is £12 for a similar 85 cubics, but is the loudest of all three https://www.screwfix.com/p/manrose-x...ite-240v/11097
Problem is, they are all about as perky as a desk fan. Designed to work with a bit of resistance, like in a bathroom with the door closed. Your exact situation is hard to judge. Non are wired yet either.
I did once buy a mixed flow (TT) fan, thinking it couldn't be that bad. An eBay item, for about £20. It sucked so bad, I gave it the local shop so they could save others from making the same mistake.
You could probably go with the £17 fan, knowing you could add another at the air-in point. The pair will do a cubic meter a minute. If you needed a pair. Or, if quite poor, you could move the 17£ to inlet duty and put the 20£ on the roof. It's not exactly quiet, like the boxed in rvk of a cooker hood though.
I have no doubt I would be looking in the small adds for a cooker hood. Nothing else is actually worth messing about with. If you can find a neff they are great. The rotating mass is balanced individually and the very best motors used. Women want a new kitchen every week, so £20 is all you need spend. You are familiar with the noise of them, and bathroom fans.
I blow smoke at my 25w bathroom fan, and it just hangs around. The thing struggles to open it's own shutters. There is only so much corner cutting you can do, before it just doesn't work.
