Helmet ventilation and cooling for hot desert riding?

[Gwolf]

It gets plenty hot here and plenty humid too. I have a full face helmet and wear it when it is cool enough. During June, July, and August, I wear a Bell 500 with a dirt bike shield on it. It gets plenty of circulation as long as you are moving. Not much of anything helps if you sitting at a stop light, breathing exhaust fumes, behind a garbage truck with suspicious looking, stinky liquid dripping out the tailgate.

 

[JoshHefnerX]

Have you checked the venting in your helmet to make sure that foam/fuzz/crap or something isn't blocking up the channels?

 

[JoshHefnerX]

Got this article mailed to me - it does talk about what I like to call the hair-dryer effect. Science isn't completely fleshed out but does point to the fact that at some point no matter how much air flow you get you're only gonna get hotter.

https://www.bicycling.com/news/a288...il&date=090319&utm_campaign=nl17913278&src=nl

 

[UtahPete]

https://www.bicycling.com/news/a288...il&date=090319&utm_campaign=nl17913278&src=nl

Thanks Josh. Interesting reading. I think the 'fan effect' they talk about here actually making a person's body core hotter is why increasing the airflow over the body and face (as in opening the helmet visor, lowering the windshield, etc) is counterproductive when the ambient air is hot and dry.

Published in the Annals of Internal Medicine, and done by researchers at the University of Sydney, the study recruited 12 young men and exposed them to simulated heat waves of two different conditions: hot and dry (a temperature of 116 degrees and 10 percent humidity) and cooler but more humid (a temperature of 104 degrees and 50 percent humidity). They sat in front of electric fans while the heat got cranked up.

Throughout a two-hour period, the participants had their core temperature monitored according to heart rate, blood pressure, whole-body sweat rate, and a measurement called “thermal strain,” which involves rectal temperature.

Researchers found that in a hot, humid condition, with a heat index of 132 degrees Fahrenheit, fans lowered core temperature and cardiovascular measures. But in a lower heat index condition of 114 degrees Fahrenheit in a drier condition, the fans proved detrimental instead of beneficial.

In that case, rectal temperature, heart rate, sweat rate, rate of dehydration, and overall comfort got worse. That means the fans actually made the participants hotter than if they hadn’t been sitting in front of them.

Lead researcher Ollie Jay, Ph.D., told Runner’s World that more research needs to be done to determine why, but it’s likely related to evaporation—as in, how the body handles lowering its core temperature through sweating. With more humidity, the body may sweat more and the fans can speed the evaporation process. But in a hot, dry condition, fans may prevent sweat, and that keeps your core temp climbing.

Jay added that paying attention only to a measure like a heat index or just overall is not enough to determine whether fans should be used or not. Instead, humidity should be taken into consideration, he said.

Now, the study does have some limitations, particularly the small sample size of only a dozen people. Also, the mean age of participants was 25, and included only healthy men, so it’s not known if core temperature changes would be the same for other groups. That’s a significant consideration, since the National Institutes of Health noted that heat can be more of a problem for seniors, those who are overweight or obese, have high blood pressure, or on certain medications.

Also, in terms of heatwave conditions—the kind that actually cause deaths—Jay is eager to emphasize that electric fans should absolutely be used if that’s the only way to try and create more cooling. Participants in the study only sat in front of the fans for two hours, but Jay suggested that during a heatwave, fans may cool the overall temperature of a room over several hours, which could be beneficial.

Limitations notwithstanding, you can use these findings to up your comfort when you’re a hot, sweaty mess after your workout. Getting to an air conditioned room is always a good option, but if that’s not possible, try this DIY trick: Placing damp, cold towels—with crushed ice wrapped inside if possible—around the neck, or wetting the arms, legs, and neck with cold water.

This promotes evaporation, which is what allows the body to shed excess heat at a faster rate. It’s also more effective than drinking cold water, he found in a previous study. Then get in front of the fan or a good wind, because the airflow will be working with the evaporation to speed heat loss, he said.

 

[UtahPete]

Have you checked the venting in your helmet to make sure that foam/fuzz/crap or something isn't blocking up the channels?

I haven't yet done that, but I will shortly. I'm also considering opening up the vent holes if I can do so without compromising the shell's impact resistance.

 

[pegasus1300]

In searching for that article I mentioned earlier, I did find this https://www.youtube.com/watch?v=8liZhfpEtYo . an interesting idea and they did mention being in Arizona

 

[UtahPete]

In searching for that article I mentioned earlier, I did find this https://www.youtube.com/watch?v=8liZhfpEtYo . an interesting idea and they did mention being in Arizona

It seems they no longer carry that helmet, but they do have that strap-on device made in India https://www.slatinmotogear.com/collections/summer-collection/products/blu-snap-helmet-cooler

 

[UtahPete]

Never found much relief here from the heat. I tend to not ride in the heat, just too hot out. If cracking the visor open a notch didn't get enough air flow, I doubt any helmet would via venting. Could try a white helmet if you don't have one. Color does make a difference. Look like you're wearing an egg on your head or people confuse you w/ the PD, but it would be cooler.

Cracking the visor puts hot air on my face, which I think is counter-productive. Not only does it dessicate my face (which is already dry) but none of that airflow makes it up into the helmet where it can help cool the scalp by evaporation of the sweat.

 

[MikeBayne]

I think that you have to determine whether you value safety or comfort higher. I lived and rode in Tucson and Phoenix for 50 years and sold motorcycle parts for 20 of them - took a lot of instruction from Bell, Shoei and Arai. Their determination was that any compromise of the shell of the helmet would compromise the safety of the structure. If you land on the back of your head in this helmet are you going to get an intrusion from the a/c unit, maybe a haircut from the fans? My solution was always full coverage when it was cool, open-face (or Ford) when it was hot.

 

[UtahPete]

I think that you have to determine whether you value safety or comfort higher. I lived and rode in Tucson and Phoenix for 50 years and sold motorcycle parts for 20 of them - took a lot of instruction from Bell, Shoei and Arai. Their determination was that any compromise of the shell of the helmet would compromise the safety of the structure. If you land on the back of your head in this helmet are you going to get an intrusion from the a/c unit, maybe a haircut from the fans? My solution was always full coverage when it was cool, open-face (or Ford) when it was hot.

I agree about the safety / comfort trade-off. For now, I'm of the opinion that overheating of the head is an unsafe riding condition. So, I'm looking for ways to safely tour in the desert heat, including keeping my head from overheating.

 

[JoshHefnerX]

I haven't yet done that, but I will shortly. I'm also considering opening up the vent holes if I can do so without compromising the shell's impact resistance.

If you do, post pics.

 

[UtahPete]

If you do, post pics.

My helmet is a white HJC-IS Max II. (BTW, I used this opportunity to wash the liner and pads for the first time in 3 years - they were pretty grungy).

I opened up the inside of the helmet (i.e. removed the liner and pads) and blew out the 6 air holes with my compressor. There was no blockage in the ports (holes). I decided not to modify them in any way. Attached are some pics of the helmet inner with and without liner. Should be able to see the six holes, which are in two channels running front to back. Also, the liner has slots in it corresponding to the channels.

So, it is what it is; plenty of venting for a standard, popular helmet, but still inadequate for hot desert riding.

 

[UtahPete]

The next thing I'm going to try is to figure out a way to improve the aggressiveness of the air intake scoop. I imagine it's made low profile like this for reduced turbulence and noise, rather than optimizing the capture of incoming air.

Any ideas from the ingenious D-I-Y'ers out there?

 

[Gwolf]

The next thing I'm going to try is to figure out a way to improve the aggressiveness of the air intake scoop. I imagine it's made low profile like this for reduced turbulence and noise, rather than optimizing the capture of incoming air.

Any ideas from the ingenious D-I-Y'ers out there?

View attachment 175474

That will let more air in, but if you get caught in a thunderstorm, it is also gonna let a few gallons of water in too, unless you come up with a way to close it off when it is raining.

 

[UtahPete]

That will let more air in, but if you get caught in a thunderstorm, it is also gonna let a few gallons of water in too, unless you come up with a way to close it off when it is raining.

You're probably right. I'm betting I won't though. I'm desert riding; we have dry rain here! :joke:

It does have an open-close slider.

 

[pegasus1300]

If You increase airflow wont that contribute to the blast furnace effect? Or are you hoping that the head sweat and increased air will be enough to cool you?

 

[2dogs]

Everyone knows or should know that its air, or moving air, and liquid that cool our engines. Air over cooling fins or air through a radiator. Radiators contain water and engines contain oil. Those liquids all add up to cooling, and much more. For us, its blood and perspiration, sweating. The evaporation by moving air keep us cool. I use a Cool'R helmet liner from Cycle Gear and keep it damp as often as possible. I also use a cooling vest and keep it full of water. All that in 110 degree temps, at 55/60 mph, makes riding worth while. I noticed that Harley riders wear full black leathers in the summer and don't complain about being hot. They don't get any air. So, maybe there's something to be said about that study by the University of Sydney.

 

[UtahPete]

If You increase airflow wont that contribute to the blast furnace effect? Or are you hoping that the head sweat and increased air will be enough to cool you?

I'm thinking that increasing the airflow through those passages in the helmet will produce a cooling effect on the scalp as it evaporates the trapped sweat.

 

[lonestar2112]

When I wear a helmet I always wear a due (sp?) rag. In hot weather I make sure and soak it with water before I put my lid on. It keeps me head cool for 30 minutes to an hour. I wear an Aria, XD-4 visor ALWAYS open, I get too hot if I close the visor. The helmet is white to keep it as cool as possible.

 

[Peter Aawen]

:agree: with your post UP, altho if you increase the amount of airflow IN to your helmet, you'll also need to increase the helmet's capability to let air OUT, or you'll end up with a pressurised hot air box on your head! You need air FLOW over your sweating head to cool it down, or you'll just bake in there! :gaah:

That's why the SHOEI GT-Air's have front vents AND a rear vent - it helps get the air out in a place that means the air-flow is travelling over the head areas where most of us sweat and it helps cool the head that's inside the helmet! And the vent holes on my helmet are a fair bit larger than those pin-pricks shown in your pic!! :shocked: