they show everything but solar air hearters

[xboxman]

why didnt they show something about solar air heaters ??

i know they work i have 2 hooked up to my shop and get about 6 hours of good heat every sunny day

they even showed a car that runs on compressed air ( which that was a cool car) but no solar air heaters

[fcfcfc]

Hi: As a general comment, shows like that, I like to think of them as .org shows, are money motivated. What gets shown somehow has links to what will make money for somebody in the here and now, especially when it comes to energy. Look at PV VS solar thermal. Solar thermal is two to three times more efficient then PV, costs less for the initial equipment and yet look where the "hype" is..??.. WHY. Because there is allot of money interests tied to PV. End of story. It's always about the money when it comes to mainstream media....

In the case of this show, it could have been something as simple as to much footage and something had to be cut...

.....Bill

[finnsawyer]

Why don't you try to send them an e-mail extolling the virtues of solar air heaters?  You can send e-mails to some of these channels and maybe you will get on TV.  Or if you can't do that try to get Mythbusters interested in a solar to solar comparison.  Think creatively!  

[ghurd]

I think it is because they were dealing with magic and mysterious stuff.

Windmills, solar panels, geysers, old tires and weeds into fuel, electric cars...

A black insulated box with a glass top doesn't seem magical.  Anyone who got in a car at noon in summer understands it.

Didn't it have something about the Anasazi and ancient Greeks using passive solar heating?  Might have been another show on the same night.

The Anasazi impressed me with the simplicity.  High summer sun was blocked by the overhanging rock.  Low winter sun heated the clay(?) walls.

G-

[xboxman]

hey thats a good idea.... i would love to see if the Mythbusters  could make a better solar air heater than us.

[feral air]

The air-car bit left me thinking, "WTF!"

The narrator made it sound like it was just a matter of time before it was a perpetual motion machine. Of course in real life it takes more energy to compress the air than you can ever hope to get back out but the "futurist" narrator made it sound like the laws don't apply.

What surprised me about the air-car is that they weren't using the compressed air to make electricity to drive electric motors to power the vehicle. It seems to me that that would be more efficient overall...

Regenerative braking would be easier and if you had a couple batteries on board you wouldn't need the air-engine to be running all the time (like at stop lights). As it is the engine needs to be running all the time (at some level) to provide power to the vehicle (for lights, assisted-steering, etc).

It's basically a regular car that runs on air - instead I think they should've borrowed ideas from hybrids.

[vacuum1313]

I think that was the Roman death ray episode ;-)))))

[scorman]

WHY?? Actually it is very simple.

I am a chemical engineer and the basic premise is that air/liquid interface is more than 12x the heat transfer capacity of air/air, so moving heat by liquid is more efficient.

But the practical side is that to make such a $ investment, a solar air system would only have value during the winter and requires reasonable electric power for air handlers ..at least a solar water heating sytem can heat domestic hot water in summer, hot water can be stored, and/or heat up a pool at a time when the sun burns the longest and hottest (3x power over winter?)

Stew Corman from sunny Endicott

[feral air]

I made a setup (not as big/fancy) like the school used in that episode. With about 4 dozen mirrors I expected to be able to ignite a tinder-bundle on my little boat from about 20ft away but just like they noted, any movement of the boat at all defeats the "weapon" and adjusting that many mirrors is a pita.

I'd rather see the MythBusters try to meet Volvo's VAWT challenge. That would be fun.

[mullis1]

Yea we have the science channel,Discovery channel,Myth Busters and a few more.I never see anything on solar air heaters,solar water heaters,hydro,wind power.Could it be that big business does not want us to know.It would be great to see a TV channel that would show projects being done and tested such as the ones here.I would never turn the channel.Does anyone know of any tv shows or channels that I do not know about?

[ghurd]

I think it was this one...

http://www.history.com/shows.do?episodeId=187050&action=detail

G-

[xboxman]

i geuss we will have to make our own videos and put them on you tube about our solar air heaters

[Kevin L]

Energy density of a fluid does not correlate to efficiency.  A BTU in either system  = a BTU in.  In a properly designed vertical mount air system no energy is expended pumping the transfer fluid.  Also there are no moving parts or electrical issues to contend with.  Of course if you have some distance between your energy collection site and point of use, or need hot water for home use, a water system is the way to go.  Both systems have their merits, but air/air can't hardly be beat efficiency wise.

[scorman]

Kevin,

"Energy density of a fluid does not correlate to efficiency"

You are missing a salient point and it isn't BTU efficiency ..what goes in vs what comes out ...However, with the significant diff in transfer rates, this dictates the size/cost of the heat exchanger to get the volume of BTUs moved to where you want them.

Home heating sytems that have air ducts vs water finned tubes can have the same efficiency in what goes up the flue vs what gets delivered to the house.

A circulator for a water system can be a very small fractional hp, but a squirrel cage fan run by a 1/2hp motor uses a lot of electricity ie 5oo+ watts to move that air around AND from my own experience ..the water system heats a lot faster so uses even less juice

BUT, the basic premise that you have only very limited utility during cold weather months was not denied, AND the equipment is comparitively very expensive for that restricted seasonal useage ...add that to your efficiency equation and the answer to the origanl question is obvious.

Stew Corman from sunny Endicott

(burning cheap local renewable firewood vs expensive Arab oil)