Electrical tinting as smart windows in motorhomes

Dear RVers,
I am a student at Vlerick Management School in belgium and was assigned to work on feasibility of electrical tintable windows (smart windows) in motorhomes. I don't have an RV and can only dreaming of having one some day, so I will need your expert opinion.

My project is on windows that can be tinted electronically, unlike current tinted glass or tinting by film, which is permanent regardless of the day/weather. The idea is to allow control of sunlight during various season, such as allowing more sunlight during winter to warm the room, or blocking more sunlight/heat during a hot summer day. The electrically tinted window has a preservation of view, meaning that you can still see outside with high clarity (no haziness). Such typical windows can be electrically controlled (with small batteries, <3V) to be in the range of 5%-70% transmittance.

The technology is emerging and has been offered in other area such as architectural skylights (e.g. by Velux USA) or as sunroof (e.g. in 2005 Ferrari SuperAmerica). The initial indication shows that such product is to be very expensive, in the early stage, and as volume increases it will get cheaper.
The following links give an example:
For sunroof: http://www.saint-gobain-sekurit.com/en/index.asp?nav1=PR&id=372http://www.saint-gobain-sekurit.com/en/index.asp?nav1=PR&id=372
For skylight: http://www.veluxusa.com/products/accessories/glazingOptions/sageglass/

My assignment is to estimate, the acceptable price for end customers, i.e. RVers, for such product. I hope that fellow RVers in this forum can help me in giving a rough estimate on the acceptable price for such windows. I got information that current double glazed windows for motorhomes cost about $20-$25/ft2, such as windows by Hehr. What would one pay for a window that can be tinted/lightened with a touch of a button? $50/ft2, $100/ft2? Is such product interesting for RVers?

Thanks in advance for your assistance. I really appreciate it. I do hope that this wonderful technology will arrive for all RVers someday at acceptable price, and then we can say goodbye to overheated motorhomes.

I think the major value of a product like that would be in windshields, which by US law cannot be deeply tinted for safety reasons. If the electronic tinting was interlocked to the ignition, the motorhome windshield could tint to the desired amount when parked but automatically go to a legal tint range when the engine was started. I would pay a few hundred $ extra (total, not per sq ft) for that feature right now. If I were a wealthy man, I would probably pay more, but my desire for useful features is still limited by my budget.

Ditto Gary.

Gary  I can add only one thing,  Where can I get it?

I agree it would be most useful for windshields, but if applied there, expect insurance rates to go up as well as the cost of replacement windshields will be that much greater.

Gary, Kathy, Shayne,

Thanks for your input. I am afraid that putting in a windshield will probably a far fetch since the size, the legal requirements, etc will probably need many more years of work. To answer Shayne's question, the only commercial product that I know of, can be purchased from Velux America (see link in the first post). However, it is currently only available as skylights. I know a few people that bought such products, and surely that they have to pay some price for such novelty.

The product doesn't exist today as windshield, although I think it will need not much modifications to go from skylights into typical windows in motorhomes (please confirm me since I don't own a motorhome). That's why I thought it is an interesting project for me to pursue, as a novel study case (which I need to defend to finish my course.. oops).

I am aware that the biggest heat comes from the big windshield, and many people try to solve it today with covers or Reflectix, etc. I don't know if typical windows (in bedroom, kitchen, etc) would need such product. It might be good for show-off and to gain further reduction in heat load/energy spending during summer, but I am not sure how significant it will be. The other good reason might be to reduce direct glare from sun (which again, is my assumption, since I have never been camping with an RV). Gosh, probably I need to get a good job, then get an RV many years later, and then finish my project .

BTW, from pictures I see, it seems that today windows for motorhomes are heavily tinted. Any benefit from lightening it? (with still control to dark it, even darker than current tinting, when necessary). Sorry for pushing into the windows, as opposed to windhshield, since I believe that everybody's comment here on windshield is correct. It's just too complicated. So windows, anybody? 

Side windows in an RV often have awnings that are used to keep out the sun and heat.  The tinting is optional, but most high end and full time RVs will have it.  The best is a reflective tinting that keeps the heat out without too much restriction on the view as well as offering good privacy.  As the RV manufacturers are so cost conscious, it would be a very hard sell to get them to offer electric variable tinting, even as an option.

Marvin Window co. yars ago and still today offer a glass that is Blue tinted and reflects much heat and glare.  Don't remembe the specifics on it but this was a Therno type window.  Doubloe pane does not mean thermo, neither does Welded glass, nor insulated glass. The Blue glass worked and perhaps still does, but was very expensive.  Windshields and RV side windows are not of Thermo variety.  If they were, all sorts of things could be done with them including variationof colors.  Todays windshields  that are tinted in many if not all cases, have colorguard or Polorization in the tint.  Thus many polorized glassware for the eyes is neutralized because of this.  It's a tough project but I like the idea.

I addition to outside awnings and tinted windows, most rv's have interior shades or drapes. Liquid crystal windows are now available here for use in stationary homes, but the cost is still way too high for most people. Given that rv's depreciate quite heavily the first few years and that some people upgrade to newer and larger (or sometimes smaller) rv's every few years, it's unlikely that they would be willing to spend a lot more money initially and take an even greater hit when selling or up(down)grading, or that most buyers of previously owned rv's would pay the premium for that fancy option.

The novelty of having individually variable transmission rates would, in my opinion, be overkill. A simple 25%/50%/75%/100% would be more than adequate. I can see it now: "Honey, would you turn down the middle window on the left side a bit? Thank you, Dear"....  "No, that's too much; now it doesn't match the others, Love. Back up a little bit." .... "For cripes sake! Now it's worse than before you started. How hard can it be???!" .... "You moron, are you blind? Oh, just forget it; I'm going to bed! And before you ask, Yes, I have a headache!"

Electrical systems in rv's are, at best, unreliable. Batteries fail, fuses blow, circuit breakers trip, connections corrode or vibrate loose... well, you get the picture. When something in the window electrical system fails, who will repair it? Will it fail leaving the windows fully darkened, fully transparent, or blotchy; with light and dark areas?

If you could somehow get several major rv manufacturers to use a 'standard' window in their units, costs to manufacture the windows could be made fairly reasonable. That's not to say the price charged for them would be less any time soon; just look at the cost of a large screen LCD or plasma tv, especially the High Definition ones. The technology has been around for some time, but the prices remain high. Why? Because people are willing to pay it. Unlike television, most rv'ers don't spend endless hours looking out the windows, so the cost/benefit ratio isn't there.

When considering rv windshields, I don't believe the liquid crystal technology has reached the point where it can handle the compound/complex curves. Again, standardization would help, but I don't see that happening in the foreseeable future.

Good luck with your project!    

Ned, Shayne, Karl,

Thanks a lot for all your input. Thanks for providing perspective as RVers.

I did talk with a few of RV manufacturers (through a lot of difficulties). Price is an issue to them, as you mentioned. However it seems that while we talked a lot on this stuff being expensive, there isn't any real indication on how much it worths. The only indication I got is from one source saying that double the current price is acceptable. This is actually a good input since it means that such product might be introduced to some RVers (in the beginning), if only such price still make sense for the electrical tintable window manufacturers.

From various public sources available, it seems that the target price of such windows are about $25/ft2, which is for 24"x36" window cost about $150 per window. The issue is I don't know how much those RV manufacturers will take margin for introducing it to RVers. Let say they double the price, will $300/window still acceptable?

Given your input that RV has blinds, awnings, and RVers will eventually sell their RV for newer RV, then I start to wonder if paying that amount might be acceptable. It probably works like option in a car. I paid for heated seat, but it might worth nothing for the next buyer. May be one should make a business renting the electrical tintable windows instead  ;D

I agree with Karl. Such product will need to be introduced with 'fixed' and controlled setting. Otherwise, according to your scenario, the product should come with free bottles of aspirin. Of course, it can serve as a good excuse to have an afternoon nap 

As far as I understand about the product, the electrical system is rather simple. It's basically applying DC of, let say, +- 2V. So, a few AA battery should work well, and there shouldn't be any fuse, or any complex system. In general, in case of electrical breakdown (such as in the case your batteries are stolen to power a game-boy), the windows revert (slowly) to fully transparent.

Karl pointed many good issues, such as standard sizes, comples curves, and possibly high margin by RV manufacturers. Well, much work for people who actually need to make money in this field. Luckily, I just need to defend it by the end of my course, and life goes on. It might mean that I should forget getting an A then

Sounds as if you're short changing yourself, as per grade.  You've done much investigative work on the project that we haven't, thus we are only giving our views.  I'm not sure what the actual cost of such an operation to energize a unit like that, but I wouldn't think the cost you stated is realistic.  My own thinking is it would be much less.  Yet the Glass would need to be thicker than those used in Motorhomes.  For instance, the Blue reflective glass in Marvin's windows, when I sold them, was in the $18 to $30 bracket.  Low-E and the other gases installed in them is similar.  My own opinion, should this process be mastered would not raise the cost of more than $35 to $50.  Even more important to RV's as this time would be to install better windows, than the current type.  They could install a 5/8" vacuum space in a metal frame and insert low-E and tint.  The current welded glass isn't much better than double strength glass.  Then possibly they may be able to try the process yo are writing about, as an experiment.  Yes' it would ad weight to the RV but better heating and cooling would be the end result.  The cost of windows would rise but not by much.  JMHO  Good luck on attaining an A.

I would guess a feature such as this would first make its appearance at the ultra high end, e.g in the Newells and Prevost-based custom coaches. "Magic tint" windows would be viewed as a feature that would distinguish these rigs from the standard models and the extra cost would be insignificant on a coach which sells for $1,000,000 or more. From there it would move down to the high end standard models ($500,000 price bracket) and eventually work its way down the product line as prices came down and the technology was proven.

If this product were available now and I was buying a new MH, I think I'd avoid it like the plague for the simple reason that I'd want to see it out and used for a few years. Anything new like this always strikes me as just something else to go wrong. For a few bucks I could use removable tint film and curtains already do a pretty good job of privacy.

I remember years back when cars started sporting headlights that raise up and rotate down when not in use. I saw it as just something else to break. And how many "one-eyed" cars have you seen rolling down the road? I like power windows and don't want to go back but years back they failed on a car I owned. I had to leave the windows down while I was at work in a very dicey part of town. To repair them was a big deal.

I'd also wonder about a malfunction, turning the glass completely dark while on a highway at 70 mph. That would be no fun at all.

Just looked at the amount of window glass in my 40 ft motorhome - it's about 65 sq ft, not including windshield. If the electronic tint feature was an extra $20/sqft, that would and $1300 to the list price. Would I pay an extra $1300 for it if it were an option?  I don't think so. It's somewhere between a gimmick and a nice to have feature, but I don't see a how lot of extra value in it for side windows, which can be pre-tinted (fixed) anyway. [Windshield is another matter, as I suggested previously] But on luxury coaches it would be a small increment and probably would be standard on the high end models if it were offered at all.

I disagree with Shayne - I don't think the price difference would be as low as $20/sq ft, at least as an option.  Remember that each window requires wiring and a control switch, as well as whatever the glass itself costs.  An option that requires a complex wiring harness of its own is going to be expensive. Might get that low if made standard, though.

It also seems to me that it would make sense to not wire some windows for this feature, e.g small ones in the bath or the galley.

Would the electronic tint have value in a skylight? E.g. the shower? I'm doubtful - does not seem to me to be much reason to vary that level of tint there.

Question: can this technology increase the reflectivity of the glass (as opposed to merely darkening it)? Reflective vs transparent has more value, in my opinion, since it addresses privacy as well as sunlight and also does a better job of blocking heat transfer.

There are two costs involved in tinting that much glass.  One the cost of the electronically controlled glass in dollars, and 2: cost in watts (Very low)

As for the glass. several places have big electronic tinted windows  There is no reason they can't be used in automobiles as long as they are not used in volation of "Front windows may not be tinted" laws. an ignition interlock would take care of that

I think it would be a great product

Gary  when I referred to those prices I was referring to actual cost of the each unit not Sq Ftage.  Installation is a whole new ball game.  I referred to Glass only. and each window as a unit.  The difference in buying the same brand window with plain thermo is,. example,  $150 bucks, buying one with all the options would not exceed 200.  Now these have toi be compared it exactly the same unit with exception of the glass.  Not including Windshield you only have about 5 windows or so in a unit, that's $250 plus the cost of the 50 each for the electricly controled tinting.  Now tha'ts $500 total.  Now it may be worth it, should it be perfected to the point of mass production and to me that is the key--- Mass Production.  Example to put these gasses in thermo is very inexpensive, why couldn't this be.  Like anything else the 1st to purchase thigs are expensive as all get out.  Let it on the market for a breif time and the prices come down. Again just my opinion.

Gary,
There are at least 3 ways LCD's operate today on laptops. One is transmissive, which requires a backlight; the second is reflective, which utilizes ambient light incident to the screen, and a third uses a combination of the two. It should be possible to design one using the (second) reflective orientation of the crystals to do what you want. How, and at what cost, I have no idea.

Not including Windshield you only have about 5 windows or so in a unit,

Click to expand...

Maybe in yours, Shayne, but mine has 5 windows on the curb side plus the entry door window and another 6 plus the driver side window on the road side. Just one of my slides alone has 4 windows. Some of the windows are fairly small, e.g. 1.5 x 2 feet, but that's still a lot of switches and wiring as well as the glass.

The best solution for windows is to eliminate them altogether and put cameras in the outer skin and electronic displays in the interior. Then view the outside world through the camera lens, which could be adjustable for viewing angle/direction  and even switchable to different view screens inside. You can see out, nobody sees in and the interior screens could show the exterior view, or some other view (a favorite picture, perhaps), tv programs or nothing at all. And with no actual window, insulation is the same as the rest of the skin and water leak potential is greatly minimized.

Now there is an option worth some bucks! 

Gary,
And your 'capsule' would have a machine to generate the smell of freshly mown grass, or a field of clover, or just after a spring rain shower - maybe even generate a little cool mist or a few snowflakes. How about the sound and smell of a crackling campfire being watched on the 'window' of your choice. Oh wait, they've already got that (without the smell)!