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Ventilation in fully enclosed HPVs

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runcyclexcski View Drop Down
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    Posted: 23 May 2017 at 10:02pm
Hi all,

I've been researching HPVs on and off for several years now, and I've been receiving the BHPC magazine for about a year now. Just renewed my membership, so figured I would look for wisdom on this forum. A search did not return any hits, apologies if this has been covered.

May I ask if there is a good source for information/research on air-conditioning in fully enclosed HPVs? I've lived in many climates, ranging from Moscow 20+ years ago to New York City, Virginia, California, and now East Midlands. It appears that state of the art HPVs (not cheap!) are comfortable to ride only in mild climates like the UK and Holland, and even there may be only a few months a year.

I am fine spinning at 200W for hours, but in an HPV one deals with the still air. Even in a AC-ed gym controlled at 20C one needs a strong fan not to be miserable in the still air. I experimented with 'exercising' in the car for a few min, and even with the AC running there is condensation, particularly when it's cold outside.

Some numbers... I wonder if they make sense. assuming the human body is ~30% efficient, at 200W output one needs to dissipate 600W worth of heat, plus ~0.5L of vapour (per hr) from the enclosed space, for both comfort and visibility (the 0.5L comes from how wet my towel is when I am done in the gym). in principle, I am ok carrying a battery intended only for the AC, but a 600W AC is not a small device. I believe car ACs are ~2kW. Thus, riding a ACed HPV for 5 hours would require an at least 3 kW battery. This is heavy and defeats the whole point. Cold climates are easier, but hot climates... no clue.

Sorry for the ramble!

Cheers
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AlanGoodman View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AlanGoodman Quote  Post ReplyReply Direct Link To This Post Posted: 23 May 2017 at 10:11pm

I think any cooling system that isn't human powered would mean the machine isn't eligible for racing which would put a lot of people off... On the road as you say powering it would add a weight penalty - you may as well just add a motor so that you don't get so hot.

I can say that for me the Quest with the RaceKap on is unbearable in hot weather but without the kap on is absolutely fine even when it's pretty hot...
 

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Yanto View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Yanto Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 10:54am
You should go on BROL and ask the guys who ride in Texas, or California how they manage, I know some have rigged up fans and water sprays and utilise ice vests.

Personally I find 15 - 25 Deg C optimum, above 25 deg C it's ok until you slow down to go up a hill, especially if there is a tail wind!

My Velomobile has a nose vent, and i only use the race cap for racing as I've found an aero' advantage only above 30 mph, the flip side is overheating with the hood on which reduces efficiency.

As mentioned racing with a powered A/C system would be frowned upon and deemed as cheating!

Where are you in East Midlands? I'm just north of Melton Mowbray

I'm not sure why you think an hpv can only be used a few months of the year in the UK, it really isn't extreme enough to preclude riding apart from (for me) too windy, too icy/snowy or too foggy, and all those reasons are more to do with their effects on the velo whilst in traffic.

Ian


Edited by Yanto - 24 May 2017 at 10:57am
Ian, retired.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GeoffBird Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 12:27pm
I found in my streamliner (now Ian Squires') that cooling the head helped a lot, at least in terms of comfort, which is perhaps why people are saying it is much cooler without a head-fairing. I guess a priority for the body is keeping the brain cool? I did this with a NACA duct in front of the screen (high pressure region) with a deflector to direct air up the screen and over the head. Of course, when racing, even I was travelling at speed most the time, creating air-flow.
Right Time - Right Place - Wrong Speed
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runcyclexcski View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote runcyclexcski Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 9:48pm
Thank you for the comments! From the racing standpoint, I totally agree that any kind of a battery, even if it was used to power a back-massage seat :) would be cheating. I used to race bikes, nordic skis, and I used to run races, and it's understood that a certain degree of discomfort is a part of racing, and the adrenalin rush goes a long way.

With the fully enclosed HPVs and the AC, I meant to use them for everyday commuting to and from work (sometimes 'long' distances, say 30-60 min), going on long trips/touring, and just plain getting out and exercising.

Briefly, I am a total wuss when it comes to working out outdoors in the UK (I am in Leicester). In California (lived there for 6 years), one does not need extra motivation to get out and kick some ass on the bike. Actually this is mostly true for most of the US coastal areas, east/west, but in the Bay Area in particular, with the sun out 200+ days a year, wide shoulders, and gorgeous terrain -- it's always there for you. I would work, get out on my bike, and within 10 min I am in paradise. I would ride for 40 miles, then get back to office and work more. Good times. Even in supposedly miserable Russia, there is snow on the ground 6 months a year, so I would get out and ski in the woods.

In the UK, the entire 6 months of winter feels like one endless bummer, with rain, wind, mud, hedges, diesel exhaust, tractors, pot holes, and no shoulders. Add to this the misery of having to commute. 3 years passed since I moved, and I still can't get used to it. Today is late May, it's 24C and sunny -- the first day like this since September :).

So... as a conclusion to all this whining, I think I could handle it better if I built a shell around myself and the 'bent, may be had a radio and music going. I.e. exactly like a slow tiny car. I am still in a decent shape (still have some cat 2 left in me, from 10 years ago), don't mind the pedalling, and I need it to stay sane.

The idea of controlling the temperature just of the face and the head is a good one. The condensation could be dealt with by heating the windshield and air flow. Ice vests... now, that's some out-of-the box thinking. :) I have plenty of dry ice at work, could fill up a little tank with dry ice and use that as a supply of cold air, if needed. Or liquid nitrogen... now we are talking :)



Edited by runcyclexcski - 24 May 2017 at 9:57pm
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runcyclexcski View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote runcyclexcski Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 9:53pm
Alan, with regards to this point:

>>without the kap on is absolutely fine even when it's pretty hot...

... what do you do about the condensation on the windshield? I suppose, I am not familiar with yet with the state of the art... it could be that there is an opening on the top in your rig, and the 'windshield' is one's goggles.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote AlanGoodman Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 10:45pm
The windshield is very much like the visor on a motorcycle helmet so I can just open it a little... That clears the mist pretty quickly once on the move and I can open it fully when I stop...
 
 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote AlanGoodman Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 10:48pm
I actually prefer to just use the little polycarbonate flyscreen...

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runcyclexcski View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote runcyclexcski Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 11:08pm
Alan -- OK, got it! How is it when it's frosty outside -- does it take longer for the mist to dissipate? I see that the small screen would be less prone to fogging, but is also protective of the elements.
How is the Quest in side winds in traffic? Going downhill at 45 mph in 45 mph side winds in CA was fine on a bike, but with traffic, narrow roads and rough roads it might be different story. Actually.. hedges are good for screening the wind, that part I like about them.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AlanGoodman Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 2017 at 11:15pm
I don't use the RaceKap much - Main problem is that there is no way to carry it inside the Quest so if you go out with it on then you're stuck with it... it was fine when I used it in very cold weather though... That's when it was most useful but I'd rather just wear a hat to be honest... The little screen deflects a surprising amount of the cold air over you and definitely increases speed...
The Quest is fine in all normal conditions.
I wouldn't intentionally attempt to ride it with a 45MPH crosswind... I think that might get a bit scary!
 
45MPH downhill is ridiculously easy though... Big smile 

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