Hydronic radiant heating options, Part 3

At the end of last month's column (p. 44), I mentioned a product that was recently introduced to me as a potential threat to my business as a hydronic heating contractor. Sure, I said, bring it on. I always want to know what the enemy has up its sleeve. That's the work of a wise warrior. My contact, a lawyer, asked me to meet him at a local glass assembly plant at a given time. I showed up early,

At the end of last month's column (Alternatives to hydronic radiant heating, Part 2), I mentioned a product that was recently introduced to me as a “potential threat” to my business as a hydronic heating contractor. Sure, I said, bring it on. I always want to know what the enemy has up its sleeve. That's the work of a wise warrior.

My contact, a lawyer, asked me to meet him at a local glass assembly plant at a given time. I showed up early, thinking to myself, “What the heck could a window manufacturer have that could be a threat to my business?”

Shortly thereafter, I was introduced to the glass company's owner, an employee of his, two electricians and the lawyer who had asked me to join them. They gave me a speech about this electric window that they were in the process of patenting and said they wanted my opinion as to its application feasibility.

We then got a tour of the glass plant's operations and saw these magnificent computerized cutting tables that could cut glass to any dimension. We also saw the handling equipment, powered by vacuum, which was used to pick up these massive pieces of glass and move them around.

All this time, I kept thinking to myself, “How could an electric window possibly put me out of business?”

As the tour wound around the facilities, I watched as multiple layers of glass were placed within frames and saw this molten hot rubber mastic used to seal the edges. In the end, we walked around the corner of this rather large 15,000-sq.-ft. facility, and as we rounded the corner, something grabbed my attention.

“What the heck?” I thought to myself, “That's some seriously powerful radiant energy pulling on me.”

I couldn't tell what it was that was emitting the radiant energy, but I could feel it from clear across the shop and it kept drawing me closer. Soon, I could see what was drawing me to it like a moth is drawn to light. It was a radiant glass window. It stood approximately 6-ft. tall and 3-ft. wide and was sitting in a nice wooden frame.

Suddenly, the lawyer's statement about being a threat to my business set off bells and whistles in my head. These guys had invented a radiant window and it was working quite well.

“Welcome to Big Ben,” the lawyer said. I was amazed. I couldn't avoid putting my hand directly on the heated glass. “Feel the other side,” he said. I did, and to my amazement, it was considerably cooler than the front side. The lawyer handed me an infrared thermometer, and when I shot the heated side, it read 115°F. It was amazing, simply amazing.

The three co-inventors went on to explain the power plant, which was 48V DC. They also detailed how they had experimented with different types of bonding systems, had finally hit upon the perfect method of attachment and gotten it tested and approved under UL standards. They wanted to know how to apply it, which is why they had contacted me.

“I don't consider this a threat. I consider it a potential tool in my personal arsenal of human comfort weapons!” I said. My mind started racing 1,000 mph thinking of all the places where I could have used this very product in my 33 years of hydronic comfort experience.

I thought of the orphaned jobs we'd inherited along with perfectly uncomfortable clientele, sitting in the direct view of large expanses of glass covered wall-to-wall with baseboard. Even with radiant floor heating systems, these owners remained uncomfortable. You know the type. We all have them in our portfolio. Try as we may, we cannot get the internal mean radiant temperature high enough to satisfy the occupants all because of the glass wall's heat-sucking characteristic — until this invention came along that is.

“It has infinite R value,” exclaimed the lawyer. “It will completely eliminate window heat loss!”

I was dumbfounded to say the least, and then my tour guides took me to their “laboratory.” As we walked into the lab, I saw an upright freezer's face sitting with its face flush to the wall of the lab. The door had been removed and replaced with the radiant glass window.

“Look down at the lower left hand corner of the window between the two panes of glass,” the lawyer said.

As I approached the door, it was obvious it was on, as evidenced by the radiant energy emitting from the glass. The digital thermometer also showed the temperatures of the glass surfaces as well as the freezer and room temperatures. As I looked down at the corner, I saw ice forming on the inside of the unheated glass surface, the one closest to the 0°F freezer.

“How can that be? That can't be! The heated glass is less than a ½-in. away, sitting at 115°F, and there is ICE forming on a pane less than a ½-in. away. It can't be!” I kept saying that it couldn't be, but it was pretty obvious that it was. It was counterintuitive to everything I'd been taught and everything I'd been teaching. Heat flows from hot to cold, and the greater the differential, the greater the flow.

Tune in next month as we continue our journey into the future of radiant windows and their effect on human comfort systems. Until then, keep your windows free of ice and keep your hands on the wheel.

Mark Eatherton is a Denver-based hydronics contractor. He can be reached via e-mail at [email protected] or by phone at 303/778-7772.

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