Radiant WIndows exposed

Mark Eatherton

All,



Recently on another thread, I had mentioned radiant windows. A bit of history first. I have been involved in the development of this wonderful product for about 5 years. The original company that I was involved with underwent some changes, and unforrtunately, I and the core group of technicians responsible for applying and developing these controls were not being listen to for our input as it related to the controls.



I decided to move on, and have since hooked up with a new radiant window company here in Colorado. The new company is called Energized Glass. Their web site is <a href="http://www.energizedglass.com/">www.energizedglass.com</a> , The key differences between these two companies, is that this one actually has a business development plan, That, and they have a UL approved control that is wireless. It is my intent to eventually make a full time living from this wonderful product.



I had promised that I would post some pictures of the windows in the IR spectrum, and attached to this post you will find the promised pictures. I formally severed my relationship with the previous company last night, hence the reason I am making this announcement today.



Feel free to ask any questions that you might have.



Thanks for your patience.



ME

STEVEusaPA

I'll fire the first questions...

First of all, congrats and good luck. Seems like it should be something great!

1. What are we looking at with the first 2 pics, as far as the temps?

2. What's the outside temp when the pics were taking?

3. Are these going to be completely new windows only, or could they be added, like an indoor storm panel (or like a replacement on a Pella window)?

4. Will you need a rep in the Philadelphia area ?

Mark Eatherton

Thanks for asking Steve...

Those pictures are from a few years back, but if memory serves me correctly,



1. The first picture is of three windows. From the left to right, #1 is unheated reference window, 2 and 3 are heated, as indicated by the + with the coresponding temperatures. The second picture is the same IR picture, except it is in normal light instead of IR.



2.If I recall, it was colder than a well diggers butt in Alaska (near zero F)



3. The biggest problem with retrofit is getting electrical power to the top of the window. Much easier in new construction. The units comes as a complete IGU (Insulated Glass Unit) which can be made as a replacement for most windows (Pella excluded). It can be made in double and triple pane configurations. It is not recommended that these windows be installed on the inside of an existing window due to fogging potentials of the existing glass.



4. I would have to refer you to the owner of the company, who's name is at the bottom of the EG web site home page. (Dave Lundahl).



I have a total of 16 of these windows, and I L O V E them. Nothing like sitting right next to a warm window, looking outside, on a cold an snowy day. These puppies are THE answer for those highly glazed situations where humans will be in a static condition in near proximity to windows.



Thanks for asking!



ME

Gordy

Congrats Mark

On moving on with the program some where else. Its amazing how management can be a "show stopper".



I can't believe the potential of these windows. I do see a bigger market in the replacement window sector. Especially with the bubble bursting in the residential, and commercial building markets.



The only draw backs are the areas of the country with higher electrical rates. And me not having any radiant windows.



As been discussed before these are the answer to ultra low load homes. Windows, mirrors, Maybe even a glass block wall where each or every other block is radiant hooked in series like PV shingles....... The mind tends to wander with exciting stuff like this.



Gordy

Mark Eatherton

Thanks Gordy...

It HAS been a long and interesting road.When I first got involved with the original inventors, my mind went nuts. I don't think I slept for at LEAST the first two years :-) Of course, some of that had to do with the fact that they were using DC, and the fact that the glass got hotter than blazes with their AC to DC converter. Come to find out that the AC to DC drives they were using were letting 100 VAC slip through to the glass, and THAT was why it was getting so freaking hot. Oh well, upward and onward.



The new company uses only AC, although their controller could be used with straight DC power if that was the only alternative. This new company also doesn't limit itself to putting the buss bars on the long legs of the window, but HAS to go (in most cases) with the bars on the short side, thereby inducing current through the greater path of resistance. It has to do with the glass reactance. Otherwise, with the high voltage and lower resistance, the glass can take off on you in a hurry. The new company also does not limit themselves to one hard coat low e manufacturer. They can use any of the hard coat pyrolytic coatings between 10 and 60 ohms resistance.



The new solid state control is a thing of beauty as well. It pulses energy to the glass, and can increase or decrease the pulse width based on deviation between expected set point and actual glass temperatures.



The next generation of controller will have the ability to "group" a set of windows together to be served by one primary circuit, and will rotate their use of that circuit based on not more than X units being on line at any given point in time. That means we can use one 20 amp circuit to handle numerous windows, instead of requiring one 20 amp circuit per window.



The new controller also tracks KWH consumption on a per window basis, so if the consumer thinks that their windows have increased their energy consumption,we can track energy consumption on a per window basis and show them exactly how much energy it has used.



The bus bar design for the new windows are a patented spring loaded Z bar type of contact that allows the copper and glass to expand and contract at their differing rates without affecting the electrical "Bite" on the glass.



Above and beyond keeping humans in close proximity warm and comfy, these beauts also have a definite application is high humidity environments. A glass surface temperature of 70 degrees F will NOT allow ANY condensation to form on the glass surface. Think large swimming pools, hot tub rooms, and hospitals with high RH for their recovering patients.



As you can tell, my mind is still racing ;-) I now find myself driving around, looking at large pieces of cold unheated glass saying to myself, "We could make this situation MUCH better..."



Although it is not recommended that these windows be used as a sole heat source, we have actually done whole house heating, but it is cost prohibitive in most cases ($/therm). In cases where we are maintaining the glass at between 70 and 75 degrees F (thermally opaque condition) the electrical consumption is minimal. Besides, sitting next to a window running at 120 degrees F feels like you are standing in the sun. Feels OK for a while, but gets uncomfortably warm after a while.



As far as you not having one, I can take care of that ;-)



And yes, we are being spoken to by the Passiv Haus folks. The only reason they need heat is because of the window loss. Got that covered... We are looking at two of them (PH projects) as we speak.



We are also putting two HUGE curved glass heated windows into the Sleeper House. Yes, we can do curved and bent glass.



They make this low e glass in thicknesses as thick as 1". I'm thinking off peak electrical storage systems. Glass is an excellent conductor of heat and holds heat quite well, and emits it very well too.



But I digress....



Thanks for the well wishes.



ME

SWEI

very cool

and it sounds like they've actually done their homework.  Good luck with the project - I'm already thinking of a few applications down here.



I assume the controller has some kind of leakage current detection?

Mark Eatherton

Every controller undergoes a severe voltage leakage test...

BEFORE it is shipped with a window.



There is a glass break detection circuit that will disable the power to the window if it breaks to avoid frying burglars...



Hmmm, maybe we could eliminate the glass break detector and have a new security system was well. Nahh, I can see it now, "Homeowner sued by burglars for electrocution".



Never mind ;-)



ME

Gordy

simple fix

Warning high voltage ! Multiple language of course. may have sales benefits

Mark Eatherton

Power Point Presentation for Electrical Engineers...

I just completed this for the electrical and mechanical engineers that are new to the radiant window concept. BTW, it is no longer a "concept", but rather a proven means of guaranteeing excellent human comfort.



Let me know if you have any questions. It's not real simple, but once you grasp the electrical concepts, it is quite easy to wrk with.



Next, an Architects Guide to Radiant WIndows...



ME

RobG

Windows

Mark, back in the 80's, I was a crew chief on Blackhawk helicopters and they had heated windows for de-icing purposes. I believe the glass sandwiched a layer of thin (transparent) gold. they were DC powered and would get very hot to the touch from the outside but the inside did not generate much heat at all. Did the concept of these windows come from the aviation industry or am I off base?

rob

Mark Eatherton

The HISTORY of energized glass...

Rob, it was originally developed and conceived during WW2, to allow the glass in the belly of B series bombers to stay warm, and keep the bombardiers breath from fogging up their view of where they were dropping bombs.



From there, it was used in the Ford Thunderbird.



From there it was used in the doors of reach in freezers in grocery stores to keep a clear view of the product on the inside.



And finally it is being used in architectural considerations.



Someplace in between, it was incorporated into the viewing windows of electric stoves to assist during the "Cleaning" cycle, and is also used for keeping food warm in food production/delivery lines.



So, yes, you're correct. It was originally conceived by the Air Force, and exploited from there.



We've even looked at incorporating it into the armored glass of HumVee's, but the problem is a lack of power availability. We are still working on that one... The internal hydronic FCU takes about 2 hours to get a frosted windshield to dry out. Needs to be ready to rock and roll in a LOT less time.



We were warned a long time ago to not even consider moving into the automotive/transportation lines due to Ford holding most of the patents. The HumVee people came to us with a problem.



Thanks for asking.



ME

Dennis Bellanti_2

Ford

Mark, Good move!  Do you know what years Ford used heated glass?

Mark Eatherton

I had heard....

and I think I also read it somewhere, that the 56 and 57 T Birds were the first, but this link says otherwise...



http://www.glasslinks.com/trivia/trivia3.htm



Like all other radiant products, looks like it got too expensive and was discontinued, even in the after market. ;-)



Would you like to buy one for your office so you can say that you have the 2nd radiant window conditioned hydronic's office in the World (the FIRST is in Heeney Colorado)?



I think I owe you lunch...



ME

PHPPer

Possibility of PV powered?

I recently went into discussion about PV becoming more economic to heating air than Solar Thermal to hot water.  Radiant windows are the answer to comfort. I would love to convince my current client that PV could power a window that could keep the main room really comfortable, while the other two small rooms will be the same temp.



The root is that when you need the heat the sun isn't shining.  This is in a Passive House so I doubt they'll need heat in the evenings while they sleep, and the home is modeled to collect all the sun it needs to sustain all night.  I can't figure out why a supplemental window to PV kit wouldn't work. argg. The agony of the nerdy.



Mark, you rock, and the last presentation you posted I really LIKE!

steve_25

Radiant Windows exposed

Very Cool! Hmmm? Very Hot! Sounds like a brilliant idea. This opens up alot of floor space design opportuities that was otherwise off limits in conventional architecture.

Mark Eatherton

Solar, absolutely...

Why not take a resource that is "free" and use it to pump solar energy into places it is badly needed, and never shines.. that being the North facing windows. One could actually "bank" solar energy on the North side of a building, thereby increasing the MRT, and allowing it to drift off over night until the sun starts shining again the next morning. In situations where the voltage is low, the bus bars are applied to the long legs of the window, giving us a path of less resistance, giving higher wattage with lower voltage.



If nothing else, a person could use stored solar electricity to maintain the windows in a "thermally opaque" condition, meaning the room does NOT lose any of its heat through the heated windows, and then fall back to off peak electricity at night to actually help heat the home. Homes typically lose about 25% of their energy thru the windows...



Speaking of off peak electricity, we have some preliminary designs utilizing this very same glass, except 1" thick, that can be used for off peak thermal energy storage similar to the STEFFES systems that are out there right now, except if one of our wires fails, we can fix it without having to completely disassemble the whole shebang to fix it. And I have already incorporated a very efficient hydronic component into this very design (think aluminum heat transmission plates and copper tubing to extract the heat out of the glass and put it into the water.



The future for solar and this product are VERY bright. In fact, we have some existing customers with PV solar in the mountains that want to incorporate our heated glass over their arrays to remove major snow accumulations that would block the collectors for up to 2 weeks, if allowed to clear on their own...



Exciting stuff for sure. Thanks for the kudos.



ME

Mark Eatherton

People who live in glass houses...

Can now at least be comfortable. And if they want to throw rocks, let' em. Every one of these windows HAS to be safety tempered. IF they are lucky enough to actually hit the glass with a significant point, the glass breaks into the small corn shards, not the long deadly sword shards associated with conventional float glass.



And we, as comfort contractors, now have the ability to deliver an excellent radiant comfort condition, even in areas with highly glazed North facing areas.



ME

DanHolohan

More than 1,400 people have read about this so far.

I like that!

Gordy

Intended design, and use

Mark,

  I'm wondering if this type of glass would be more cost effective at just off setting heat loss of the window. Say its set to maintain 65-70 no matter the outside temp (to a point) thus reducing the heatloss of the glass.



My thinking is more to the replacement window market, and specific kinds of windows. Like existing nice wood windows with storms, and screens. The storm would be the radiant window used in the winter. Instead of a full blown rip out the window. The storm frame could have the glass replaced, and wired with radiant glass. I can see the benifit in window condensation control along with off setting the heat loss of the window.



 Lets face it . It takes a lot of money to replace a whole window with a new whole window that gains an r value of only 1-3 more over the old one. By only replacing the Storm window with radiant glass replacement cost drops.



Just thinking of the market of windows. The hard sell is the cost. Over the gain.





Gordy

Mark Eatherton

I like that too Dan, Thanks for making it happen.

You're one heck of a good guy ;-)



ME

Harvey Ramer

Mark, if I may, I would suggest

Powering these windows With 240 VAC if at all posible. One of the reasons is that it would automatically balance the electric panel and lower electric costs. The electric meters always read KW on the highest leg an multiply it by 2.

Another reason is many people's electrical systems leave a lot to be desired in there neutral/grounding. The electric companies ground also gets overloaded. This causes stray voltage. I struggle with it all the time. We can't feel it but cows sure can. It has put more than one dairy man, in my area, out of business due to the decrease in milk production.



Just some food for thought.

Keep up the good work.

Gordy

Balanced electric service panel

 Harvey while you are correct about the way the meter reads the highest leg of the panel its nearly impossible to have a balanced panel with most of the residential usage being 120 V. About all you can do is insure the 240 stuff is balanced that gets extended use such as AC in the summer, or an electric dryer. So yes something like the radiant windows that will see steady usage for a period of time this is a good thought.



 As for the savings on a balanced panel it pretty much averages out to an unbalanced panel when talking the 120 V use. Pretty hard to control that.



A watt used is a watt paid for really not a savings issue on the meter.



Edit:



In industrial, and commercial use Panel balancing is more crucial when loads are near 100% for extended periods.



Gordy

Mike Lampkin_2

Availablity for Canada...

Hi Mark,

     Congratulations on your new business adventure and I hope that all is going well with you. With the new Energized windows, I wanted to ask what is the efficiency of the window? Is there much heat loss through the outside glass? The window technology sure looks impressive and I see that the window is UL approved. As of now, will Enerized Glass be shipping to any dealers in Canada? Thanks for now.

Mike Lampkin

Mark Eatherton

220 potential...

Gents, the windows can be powered with any power source that uses 2 wires (eliminates possibility of utilizing all 3 phases of 3 phase power), however, it is currently only approved by ETL for 120 volts. I have tested them in the lab with 220, and it makes for a FAST acceleration of the glass, and requires a very intelligent, fast acting PID control to avoid over driving the glass, but it is doable with off shelf componentry. The big problem is that every time you change something on these devices electrically, it has to go back through the ETL review, and that is not an inexpensive (typically $10K + depending) proposition. I will make the suggestion to the manufacturer for future considerations.



Thanks for the great suggestions, and keep 'em coming ;-)



ME

Mark Eatherton

Oh Canada...

Mike, Shipping glass cross country is doable, but expensive from the standpoint of making crating strong enough to withstand usual trucking abuse, plus glass is H E A V Y...



The manufacturers long term plans is to establish regional manufacturing facilities at existing Insulated Glass Unit manufacturers. This will alleviate most of the shipping issues. At present, we do not have a facility in Canada, but that could change in the near future. If you know a good quality IGU manufacturer who might be interested, have them contact Dave Lundahl at energizedglass.com.



As it pertains to back side heat loss, when at design condition (0 F outside, glass running at 140 F) K.S.U. had determined that the back loss was 15% of the energy being imparted as a whole. I don't have a high trust factor in that number, because the lab that did the work was looking at the GROSS electrical consumption through a fairly inefficient AC to DC converter, and it was about 50% efficient (100% converted to heat in one form or another, but not where you wanted it to be), hence my reluctance to believe their numbers.



Determining the back losses is done using an energy flux sensor, which are not inexpensive, and requires a special processor to convert voltage signals to btu/sq ft/hr heat flow values. It is going to take some time, money and development of a testing protocal to determine the net operating efficiency, and at present, there is not even a dynamic glass manufacturers organization to establish the required testing protocals and standards necessary to level the playing field. We approached the US Government (NREL) about the possibility of establishing protocals, but they were too busy evaluating other dynamic windows (see SageEC) to give us the time of day...



My gut feeling is that when operated in the thermally opaque mode, the standby/back losses are minimal and will be offset by the buildings increased operating efficiency, but again, this requires time, exposure and applications in the field in order to properly and fully evaluate their potential. I have said all along that these are a H U G E comfort tool, and IF there is any fuel savings, it is icing on the cake. Obviously, if used with alternative energy, you can "induce" R value into the glass, giving a substantial benefit to elimination of conventional window heat loss from within the building. I would LOVE to take an existing old school passive solar home, and retrofit it with the radiant windows in the T.O. mode and see what the net effect is as it pertains to overall energy consumption. I KNOW what the comfort effect will be ;-)



Thanks for asking Mike.



ME

Mike Lampkin_2

Rad Glass

Thanks Mark, I'll pass Dave's name on to the window people that I deal with. I was speaking with them last week and they are very interested in learning more about the Energized Glass product. Like you say, the comfort factor and the non condensing glass are really going to drive the product. All the best to you.