Bigger fan better numbers?

Hi All, first post, so sorry if this has been raised previously.

BAsically, wondering if I get a bigger/better fan, my performance on the indoor trainer will improve? I’ve got a small rehcargable fan, which attaches to my Wattbike. It does the job, but when I’m doing a longish sweetspot effort I feel as if my HR keeps going up and I’m wondering if better cooling would help kee my heart rate under more control as it’s not working as hard to cool me down?

Thoughts (and any good fan recommenations) welcome!

I don’t think people realise (until they get something with some power) how much of a difference it will make.


Welcome. See the topic covered here:


Yes for sure if you subtract the overhead that cooling imposes, your numbers will improve.

I am using a Core temp sensor, the following two intervals show a 10 minute interval just above base core temp of 98.6, the second one at 101.0 degrees. I kept the heart rate the same and let power land wherever it landed.

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A core temp sensor? Like, erm, up the :peach:?!

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No this one


Good stuff, appreciate it!

I firmly believe most people have insufficient cooling. It can be a massive limiter on power. If you find excessive sweating and pooling on the floor, that is one sign you can likely benefit from more and better fans.

I use 3 of the Lasko blower fans and wouldn’t go back to anything less for normal training. Doing heat adaptation training is a separate topic, and the only reason I would consider less cooling. But it is usually limited to 2-3 weeks timing before an event.

In all other cases, more and better fans = WINNING!

Edit to add my fan setup, and note the ducting that gets cold air from the window.


Two Air Movers (Vacmaster) in my unheated shed even this time of year. One on the floor blasting up, and then one torso height. I can reach the switched socket for the one on the floor, and can reach the torso height fan itself. The only thing that changes by intensity is the torso aimed fan setting. Both would be on for every workout, even Recess.

I try to have the door at least a little open too - for fresh air, and also for ventalition since the pain cave has undergone gradual lockdown conversion to a home bar too (so more sealed than it was pre-covid!).


I used to do all of my VO2max workouts outdoors because I could put out better numbers.

Now I have 2 hugely powerful Lasko-like fans (more powerfull than the Laskos) and can hit my marks indoors too. N=1, but for me bigger fans = way lower RPE = better numbers (I can‘t flog myself at max. RPE forever, I am weak :roll_eyes::grinning:). It‘s not only fans either: squirting some water on my legs and down my back in the middle of a Zwift race, after a hard section, lowers RPE by 1 or 2 pretty fast…

I also have a lignering feeling that oxygen plays a role too: if I open my windows RPE tends to go down too). I have a pretty air tight house, and can raise the ambient temperature quite a lot by working out :man_shrugging:t4: I guess the oxygen levels in the room trend down ever so slightly too…


Lol, I used to have two large fans in my pain corridor (an 18inch gym fan and a 16inch remote control pedestal fan) but in my temporary pain cave I have only a 9 inch floor/desk fan. I have just ordered another to see if I can eek out another watt.

3 fans = 5w/kg


Well, at 4w/kg & 3 fans… what’s my problem :wink:


Must not have them angled quite right! :laughing:


If you have the space for the fan and for the air to move around… Search for ‘industrial drum fan’ on amazon. I have a 24in that gives me a full body breeze, on high its 4500 cfm. And it isn’t that loud because the blades spin slower than a smaller fan. I use it in an apartment and its quieter than my HVAC and just sounds like white noise outside my door. No complaints from neighbors.

Is this industrial drum fan of yours belt-driven? The sound level between direct drive and fan-drive can be immense.

I felt the difference this year… Basically a proper fan will be too cold for warmup and just right for the workout. Having a 2nd less powerful one in another direction could be a good one to have during warmup

Like someone once said…marginal gains.

And if you notice that your RPE decreases with a small fan then a more powerful fan will be even better. I haven’t reached the point of needing more than 1 fan but maybe that’s the next marginal gain?

This is a link to a really good fan and a discount code.

1 Like allows you to turn all your fans on once warmed up, without getting off the bike

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Mine is direct drive. I don’t know how accurate the app I used on my phone to measure the volume was, but it read ~72db for the fan at full blast (3700+ CFM) and it was reading 75db for my HVAC.

Doing 3x20 sweet spot tomorrow and will be enjoying the full body breeze I get. :rofl: