We installed two 30 tube panels on our roof in 2006. They made 100% of our domestic hot water and contributed a tad to our in-floor heating. We recently ordered 3 more panels to add to the existing 2 because we wish to heat our house even more using solar thermal panels.
In order to add on, we had to remove the existing tubes so we could drain the system. While we were removing the tubes we found 23 of the 60 tubes had gone bad. Upon inspection, we found the slim copper tube inside the glass had expanded and split at the bottom. The copper looks like a bloated puffer fish! This released the water inside the copper and made the tubes useless in conducting heat. We live in northern Wisconsin and it’s not uncommon to have -20 degrees for weeks on end. We believe the copper inside the evacuated tube froze and burst. We don’t know if the vacuum had been lost, and thus lead to freezing? Each tube seems to be completely in tact, no glass is cracked or broken. Even the seal between the glass and the metal looks fine. Can the liquid inside the copper freeze even with a vacuum? And why did 23 of them go bad and not the full 60?
My husband believes the vacuum still exists in those bad tubes, but the copper still got cold enough to burst. He believes this because there is a stretch of coiled metal going from the glass to the big copper head at the top of each tube. It’s the skinny neck part. This neck part isn’t insulated. This neck is exposed to that cold air on frigid January nights. Could that cold be entering the neck and traveling down the copper tube and freezing it? He believes this is what happened. He believes the 23 unfortunate tubes were the ones that slipped a bit past the manifold and really got exposed to the cold air. They slipped a bit when we cleaned the snow off them. When I slipped a bit, I mean like 1/4 inch. There’s nothing but a strip of plastic on the bottom of the manifold protecting that neck, and the tubes could easily slip a bit beyond that plastic strip. The new Kingspan tubes have a clip to hold them into the manifold so they can’t slip. But the necks still aren’t insulated. Don’t they think cold can penetrate that uninsulated strip of plastic?
To add insult to injury, Thermomax was bought by Kingspan Solar in 2007, and all tubes sold before that aren’t covered under warranty. So we lost our warranty. But since we already have 37 good tubes, racks, and a system in place we will be purchasing 23 more tubes from Kingspan. But we are going to insulate those wire necks ourselves to make sure they don’t freeze.
Also, we never would have known these tubes were bad if we hadn’t ordered more panels. We don’t annually go up on our roof to check tubes after winter has passed. We never thought it was something we had to do. Kingspan says they’ve not have any complaints on solar sold to northern climates. But do those panels get checked annually? Maybe they have bad panels and don’t know it.
Looking at our solar thermal panels data, it seems the tubes went bad after the first year because our production really dropped. We thought it was just a really sunny first year and never thought about it more than that. If we would have done an annual check up, we could have maybe caught it soon enough to be under warranty before Thermomax went belly up. If you wish to install evacuated tubes in a cold climate, be prepared to annually check your tubes.
1) Heat pipes are very difficult to find any decent information on solar thermal panels.
2) No system should have the water to be consumed running through the collector or header. Very few places have water clean and soft enough to allow that. The system can still freeze which requires a separate loop for the water to the tubes/panels.
3) To use methanol or other antifreeze solution other than propylene glycol requires a double walled heat exchanger to prevent the solution from getting into the potable water – nothing different and nothing new. With the mandatory double walled heat exchanger it is definitely not against the law.
4) infered thermometer? maybe you intend to say infrared thermometer – never heard of the other thing. An IR thermometer to measure temperature is the worst idea one can come up with – let 10 different people measure the temperature of an object and you can easily get 10 different temperatures. Everything depends on the emissivity of the material at that temperature and the emissivity setting of the IR device.
A digital thermometer with a contact probe will provide an accurate result.
Solar thermal panels introduction
Introduction
Subject or keywords: solar thermal panels
Content
flat plate solar thermal panels
In the solar thermal utilization, the key is the sun’s radiant energy turned into heat energy. Because solar energy is more decentralized, you must try to put it focused together, solar thermal panels are key part of the device for solar energy using. Due to different purposes, solar thermal panels and solar adopting system is divided into many kinds of type, the name is also different, if used for cooking, the solar ovens used to produce hot water of the solar energy water heater, if used in the drying goods called solar drying machine, if used for smelting metal solar furnace, and the sun room, solar thermal power plant, the solar energy water desalination is waited a moment.
The solar thermal panels collector efficiency is higher by collecting and absorbing device component. By different wavelengths of visible light sunshine and not visible composition, different material and different color to the different wavelengths of light absorption and reflection ability is not the same.
The black color has the ability to absorb sunlight in the strongest way, so general with dark or black cotton cloth. White reflected sunlight ability are the strongest, thus the summer shirt is pale or white. Therefore using the black color can get hot. Let parallel sunshine through focus lens gathered in a little, a line or a small area, also can achieve the purpose of collection hot. Paper in the sunshine, no matter how strong the sun, even if it is in the hot summer, also won’t be lit from the sun. But, if use solar thermal panels collectors, the sun gathered on paper and paper lit. Collectors can generally be divided into flat collectors, focusing collector and plane mirror etc several types.
Solar thermal panels are used for solar energy water heater, etc. Spotlighting collectors can make sunshine focus for high temperature, the focus can be a patch or linear, used for solar power, the building heating heating and air conditioning (air conditioning), solar oven, etc. According to the condenser structures “usual Fresnel” lens, a parabolic
Solar thermal collector panels
Flat mirror, used for solar power tower, tracking equipment, general and a parabolic mirror joint use. The sunlight reflection on the diagonal, on a parabolic mirror, a parabolic mirror to focus on it.
Solar thermal collector panels are defined as the absorb solar radiation and the heat energy produced is passed to the heat transfer medium device. This short definition it contains a rich meaning: the first: solar energy collector is a device; The second: solar thermal panels collector can absorb solar radiation; Third: solar thermal panels can collect and produce heat; Fourth: solar thermal panels collector can transfer the heat to medium liquid
Solar thermal panels collector, although not directly to consumers end products, but solar energy collector is key component comprised of all kinds of solar thermal panels utilization system . Whether the solar water heater, solar ovens, active the sun room, solar greenhouse or solar drying, the solar energy industry heating, solar thermal power generation are all dependent on solar energy collector, are based on solar thermal panels collector as systems of power or core component.
solar water heater is becoming more and more popular, last December 1st, the implementation of the building energy efficiency in Guangzhou “measures for the administration regulation,” newly under 12 floors house must be installed solar energy systems, now on the newly built residential areas in the roof everywhere we can see shining solar thermal panels and huge solar water heater tanks. However, a survey showed that many of the solar water heaters is on “strike” during winter! This can let buyers painful for winter use of solar energy water heater
case
A solar water heater in winter “on strike”
“Ah, my household solar energy water heater, as long as the temperature outside drops under zero degree the system will be frozen!” Beijing citizens Ms. Liu the most these days unhappy, is the home of the solar energy water heater strike. She told reporters, oneself this year may move in the haidian new home. When considering the live in top floor, so have installed solar energy water heater. Compared with electric water heater, ms. Chen feeling, the solar energy water heater is really good, energy conservation and environmental protection, and the temperature of the hot water is not low.
Unluckily, in December, the solar energy water heater her home but not make of, first, the highest water temperature heat water every time only 40 ℃, cannot used for bath, the other day, the outdoor temperature is below zero, water heater didn’t work- , no water run out, to her supprised of solar energy heater’s water pipe have been freezen.
It really made liu is painful, as family to go out in the cold bath. But under, she call manufacturer, and officials said their water heater in the instructions for use on said very clearly, in case of low temperature time, user should have had to boil and heat the water, in order to prevent the water pipes from frozen.
The personnel of the service’s words were, let madam liu some hard to accept. In her eyes, one key reason to buy solar energy water heater is energy saving, and now a in the winter, she have to 24 hours to heat water with electrical or by gas, this obviously against the energy-saving concepts , not deceive people? She also wonder whether other factory solar water heater, and her as bad luck and have to warm water on-herself 24 hours ?
data
More than forty percent of the “solar” will “hibernate”
“Liu experience is definitely not the case. We have a nationwide survey indicates that some solar energy water heater to a winter hibernation ‘ ‘.” Nanjing consumer association of relevant personage to reporter provides a set of digital-they recently in Shanghai, Beijing and other cities united do according to a winter solar energy water heater usage in the survey found, at present 40.87% of the solar energy water heater to a winter is not able to use, 66.62% of consumers hope solar energy water heater in “good in the winter with” improving performance.
To this, consumer advocates thought to cause a solar energy water heater to winter shutdown or bad to use the main reason, one small manufacturer of vacuum tube production quality is poor, specifications small, lead to hot water production system set the thermal efficiency is low. The survey found, vacuum tube in 180 cm and specifications below 180 cm of solar energy water heater, 66.2% in winter is not useful. 2 it is the anti-freeze ability is poor. Such as water tank insulation effect is poor, hot water can’t heat preservation; Frozen pipeline plugging, hot water circulation. Three is businessman or consumers build himself solar energy water heater problem was still prominent.
survey
Many of the “solar water heaters” are assembled goods
“A lot of solar energy water heater is temporary assembly, and that it also influence the compatibility of the product.” Nanjing consumer association staff told reporters that they had received a consumer complain say, buying their own solar water heater host is broken, but when he found manufacturers warranty for the after-sales service personnel actually said after the inspection, the house of his this one “solar” host to the damage because accessories, and accessories and not their factory, so we can not quality assurance. And consumers afterwards just know, this one “solar energy” is the dealer sales after assembly of temporary assembled products.
Disappear assist the investigation shows, in the survey of consumer home solar water heater product, 52.4% of the consumers by use of solar energy water heater is not the original get ready to buy, among them, 34.1% of the products on the market is dealers from with low price buys parts, pipeline, and to “buy host, send parts” banner sales to consumers after assembly. But these lines, accessories by more informal manufacturer production, not the original standard pipe, accessories, also not in accordance with the environmental requirements for a strict check adaptability, not only cannot guarantee the quality, and with the unit also don’t match. Even if vacuum tubes produced enough hot water, consumer also often for pipeline plugging, the use of frozen.
