Tom_hampton wrote:
Quote:
You can't underestimate the power of convective cooling.
You keep saying convective. However, I'm pretty sure you mean evaporative.
Convection is the exchange of heat by physical movement (eg, airflow).
Evaporation is the exchange of heat through the change of state (eg, water converting from liquid to gas).
Correctly stated, and your intended point:
You can't underestimate the power of evaporative cooling.
A window unit AC system can remove the heat in a room even at the pro rates without much trouble. They also work as a dehumidifier.
The ambient conditions are not an issue, however the boundary layer adjacent to the skin is.
Because you do not have the sun radiating down on you, there is likely a larger net flux of radiant energy away from the body. Convective transfer is about the same as outside (Depending). However, Evaporative cooling is likely greatly diminished and, unfortunately, is the most important to cooling in warm to hot conditions.
In still air, the evaporation from the skin will raise the humidity of the air around the body, which decreases the rate of evaporation from the skin as the vapor pressures become less diverse.
Now, with a fan we can mitigate this to an extent but never to the extent that we get for cooling when riding outside. This is why I do my testing in an environmental windtunnel. (for reference:
https://www.instagram.com/p/BQliI3Ulrdu/).
The natural response is "Well yes, that's why I use a large fan or multiple fans" and I will say "Yes, that will help, but even a slight decrease in cooling
eventually results in a substantial decrease in performance. This is because the issue is not the ability to produce watts, it's producing watts for a length of time.
This is where heat becomes an issue; it creeps up over time and eventually becomes a limiter to performance. So, yes, 1000w of heat production isn't a problem for 1 second, 1 minute, 5 minutes, but go 30 minutes and it makes a difference, go an hour and you're subconsciously dialing back the workload to protect yourself. 2 hours of hard effort? Almost impossible to reach the same workloads as outside.
I talk a lot - Give it a listen:
http://www.fasttalklabs.com/category/fast-talk I also give Training Advice via
http://www.ForeverEndurance.com The above poster has eschewed traditional employment and is currently undertaking the ill-conceived task of launching his own hardgoods company. Statements are not made on behalf of nor reflective of anything in any manner... unless they're good, then they count.
http://www.AGNCYINNOVATION.com