Indoor Cooling: Fan vs Open Window

Soon I will start my first proper indoor season. I’m wondering if I really need to buy a fan or just opening a huge window in front of my bike will be enough. I live up high in the mountains.

Kindly share your experience. Thanks.

Active cooling. You’ll need a fan. Usually more than one!


Unless opening your windows turns your training area into a 70 km/hr wind tunnel, get two fans and reap the benefits of training at full power.

I was stuck living out of temporary accommodation at the end of last year and struggled with poor cooling. I can go back through my training log and see all the failed workouts and my notes.
They all say something along the lines of “Too flipping hot. HR through the roof. Start earlier tomorrow”.

I’d also add that AC is divine if you live in a hot and humid climate.


For me it’s both. Two air blowers to keep the sweat down, but also the window needs to be open a bit, otherwise humidity steams up the windows and probably isn’t good for the equipment, computers, etc.


fan, not even close, 100% all setups need a fan. the rest (open window or not) depends on what if any HVAC you have for the room.

Riding outside at 20mph is the equivalent of having roughly ~7500 cubic feet per minute of air going over your body.

Get a fan. or 2. Or 3.


I guess I’ll run the experiment with a room 40-50 degrees, before buying a fan. I’m curious and nobody seems to have tested this. H

Most of us have and we’ve all gotten better fans.

Evaporative cooling works better when there is air moving over your body.

Have fun though!


In the winter my basement gets under 50 degrees and I always need 3 fans when I’m doing sweet spot. But if you want to learn the hard way go for it


Yeah, have tested in a super cold garage a few times. Seems like you would freeze when you start. But that changes soon once you get to work. Without a fan, you will be gaining more heat than you can shed, without a fan.

That and all the experience from many people says air from 2-3 VERY good fans, and cool air is a bonus.


Even in 20°F in the garage in the winter I run 2 fans on max speed. I start off with no fans for the first 10 min or so, then need fans after that point. Get the highest volume air moving fan you can


Ok. Thanks everybody. I’ll get one fan and will report back the experiment with cool temperature + breeze from open window.

Maybe I didn’t properly describe my pain-cave for the forum to understand. The gist is that I could open this door/window and practically be like if I was outside.

only if opening that door/window means you have a strong wind blowing past your body.


Another +1 for a fan. I was just about able to train in my unheated garage if the temperature was below about 5C, but it was tough to get started and warm up was a chore. Even then I’d end up drenched in sweat, and get instantly chilled after the workout.

Now in Winter I have a heater in to raise the temperature to around 12C, and use a fan during the workout - Much more comfortable.

I’ve also tried training outside on the Turbo if the weather’s been nice, but not unduly hot - just about managed once or twice. Again, for me, inside +fan is best.

Hahaha, had to laugh at learn the hard way, this is so true… I run two fans with a third as backup, all hooked up to plug remote for easy control on the bike, as per GPLama. Cheap setup from Jaycar here in NZ.

Its airflow around you that makes the difference, otherwise you are just heating the air around your body, I know somebody how turbos under and umbrella in the middle of the garden (in the uk) and they still have a fan

I’ve trained outside in 35-45f. Absolutely terrible experience. Simultaneously overheating in the core, sweating like crazy, and my extremities painfully cold. Airflow and hot is far better than still air and cold.


Pre workout I flush out the air with opening up my apartment Windows, turn the 2+ fans on and wait for the room temperature to drop. Airflow is key

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Plenty of sources say fans are necessary indoors aside from those posted here. Out of curiosity, I’m wondering if being in low temperatures indoors is just as bad as outdoors for the tendons, joints, muscles, etc. unless they’re covered with something (ie leg warmers, knee warmers, and ankle covers).

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Get a few fans.

I have a 1 fan pumping cool outside air in, 3x fans in front of bike, 1x fan behind bike.
All fans controlled by remote power switches.

I literally couldn’t do any intense workouts without them.