Solar hot water heaters require periodic maintenance, no matter flat plate or evacuated tube types. That is why I would not advise putting the collector on the roof, unless you have a safe and convenient way of accessing the collector. I am not too familar with the flat plate collectors as nuSun, inc. sells only the evacuated tube type. So this applies to evacuated tube types and may in fact apply to flat plate types as well.

The solar evacuated tubes can get dangerously hot if left in the sun with no circulating water to cool the tube’s nibs to a reasonable temperature. Unfortunately when I was installing my system I did not take adequate precautions against overheating and allowed the collector manifold to go to over 250 degrees F. Some of the tubes never worked as well thereafter. So now when I have to shut down the circulation loop and allow the water to drain back into the drain back tank, I cover the collector with a reflective tarp which keeps the collector from reaching damaging temperatures.

I installed my own evacuated tube solar hot water heater system. It was and still is a learning experience. One thing I learned is that you must take serious precautions against collector overheating. An overheated collector can leave you with evacuated tubes that are no longer running at 100% efficiency.

Now when I do maintenance on the system that involves opening the circulation loop, I place a reflective tarp over the collector before I shut down the circulation loop. Without water running through the collector’s manifold, the evacuated tubes get extremely hot, and while manufacturers claim it does not hurt them I beg to differ. After allowing my tubes to overheat twice, I can tell you some have experienced a decrease in efficiency as evidenced by the feel of the tubes. Even though the vacuum appears to be intact, some tubes are warm to the touch and that means the vacuum has been compromised at least somewhat. I still get plenty hot water on sunny days, I know if I replaced the half dozen or so tubes with warm surfaces, my water would be much hotter at the end of the day.

Being able to conveniently get to your collector to cover it up, is why I regularly argue that putting the tubes on a platform on your property makes a lot of sense. Who wants to crawl up on the roof and take a chance of screwing up your roof to place a cover on the collector. Some of my good friends will design an automated cover that will rotate up over the collector when the temperature gets too hot, thereby eliminating the need to crawl up on the roof to cover the collector. I hope the friend will let nuSun manufacture the apparatus for sales to all those who need this fix.

Good control of your solar water heating circulating pump with appropriate set points can make a big difference in the efficiency of the solar water heater.  On my system I set the turn ON point for the pump when the temperature of the collector rises 6 degrees C above the temperature in the bottom of the solar storage tank.  I then set the turn OFF point at 2 degrees C above the storage tank.  This allows the collector to get a little ahead of the storage tank temperature so that the pump does not turn on … cool the collector and then turn off, only to turn back on as soon as the collector again rises above the storage tank set point.  The controller manufacturer suggests that the turn ON set point be at 12 degrees C and the OFF set point at 8 degrees C.  I set mine a little closer because my collector does not see the sun until around 9:15 A.M. this time of year.  By that time the sun has a lot of power so the collector can usually keep ahead of the storage tank temperature and not turn ON and OFF too many times.  In the evening the sun goes behind the trees around 4:30 P.M. and the collector has a lot of stored heat so the pump can run quite awhile after the sun goes down.  By the time the temperature differential gets down to 2 degrees C, there is not much heat left in the collector so there is not much turning ON and OFF in the evening.  The consideration of course is to get as much heat as you can from the collector, but not run the 100 Watt pump for a degree or two of temperature.  Anyone needing a top notch Solar Controller can buy one of ours at nuSun, inc.  We have two types in stock, but I only have one listed on the nuSun site at the moment.

We have been having some pretty cloudy weather lately, and that has been a challenge for those of us who depend on our solar hot water systems. But I have noticed that even on days when there is cloud cover all day we still make some hot water. I read where the evacuated tube has a better track record than the flat panel in this circumstance. I have been very pleasantly surprised at the efficiency of these high tech devices.

This morning (May 19) it was 32 degrees Fahrenheit at my home with a big frost and temperature no higher than 55 degrees during the day under otherwise sunny skies and and yet we got very near 100 degrees in the bottom of our storage tank by 6:30 P.M. Keep in mind we don’t get sun on the collector until around 9:30 A.M. and shade comes over in the afternoon at about 4:45 P.M. at this time of year. In my opinion Solar Evacuated Tubes rule!! nuSun has individual tubes in stock and ready to ship.  

Ask us about quantity discounts for wholesale evacuated tubes.

Today, here in the mountains, was overcast and light rain on and off all day. But the solar evacuated tubes out back made hot water off and on all day. Sure enough the water was not scalding hot but the collectors made water that was warmer than what was in the bottom of our storage tank. Love these high tech solar thermal glass tubes. See them at nuSun, inc.

Traffic signals in small towns and rural intersections that are equipped with either simple timed signals or simple timed signals with vehicle detection, wastes a tremendous amount of motorist’s fuel and time.  The shame of it is that there is absolutely no good excuse for this waste.  Because, with a few simple changes in the intersection’s control program; it is possible to expeditiously move traffic through the intersection with little wasted fuel or time.

With the economy in taters and everyone struggling to earn a living the last thing one needs is to waste time and fuel behind simple timed signals.

nuSun, inc. has developed a Green Traffic Signalling system that largely eliminates the stopping of vehicles on a main road when a lone car is requiring access to a main road, but never works less efficiently than a timed signal with or without vehicle detection.  To learn how the Green Traffic Signals work click here.

The evacuated tube as solar heat collector is an amazing piece of technology.  It is said that the evacuated tube for solar heating was invented in Germany and then sold to a Chinese company some 30 years ago.   The tubes are relatively more efficient than flat plate collectors, but they do have some weaknesses.  There are two primary hazards, (1.)  they can be easily broken especially at the end away from the heat pipe.  There is a small tit on that end where the vacuum was drawn that is  susceptible to  breakage.  (2.)  If the tubes are repeatedly subjected to overheating, the vacuum can be damaged which renders them inefficient or worse, inoperable.

If your tube has turned white down near the barium getter, that is a sure sign that the vacuum has high tailed it and the tube is non functional.  Another dead give away is to check the temperature of the glass on all tubes when the sun is shining brightly  Any tube that feels warm to the touch is sleeping because it is sick. It must be replaced if your system is to stay at peak operating performance.

If the collector array has been mounted on your rook, you can check performance by selecting a frosty morning and any tube that is not frosty is a slacker and should be replaced.

For replacement tubes contact nuSun for brand new tubes at a reasonable price.

Carolina Electric Boats has developed a super electric fishing and leisure boat. They refer to it as Twin Troller, because it has two powerful electric motors in hollowed out channels underneath. This patent pending design makes for a very maneuverable boat that can turn in a very tight circle. It gives full new meaning to the saying, “turns on a dime”. Moreover, the boat can run through weeds, logs, dead fish and whatever else may be floating around in the water.

Talk about sneaking up on fish. This boat is so quiet, you have to have seriously good hearing to hear it running. It is really nice to go into a quite swamp and check out birds, and animals without scaring them to death and smoking them out.

What I really appreciate is the low cost of operation. What with gas at almost $4.00 per gallon, one can really appreciate going out and coming back with a lot more money in one’s pocket than if one had to fill up the gas tank of a conventional boat.

The price tag at $1,895.00 is surprisingly low considering the boat’s features and potential longevity.

Talk about a super Christmas gift. The recipient of this boat would be one happy camper.

Here below is a picture, and there are many more including videos at the Twin Troller web site.

The EM 2500 SP Energy Monitor is one neat power tracking device. It features (1) twice the voltage range (220 volts) of the el cheapo versions. (2.) has clamp on current sensors, so no need to disconnect wires and thread them into a toroidal core, (3.) a bright display and all the standard features of other power monitors. But better than all that, the price is very reasonable at $285. nuSun has them in stock so go to the nuSun, inc. web store and purchase one.

What are they good for? If you are planning any energy saving projects like a solar hot water heater, you best record the power that you are using before the project and compare it with the power that you will be using after your project is finished.

Here’s a picture of the little jewel. We call them Meter Readers.

For installing solar hot water heaters, it is hard to beat the convenience of those new fangled Gator Bites from Lowes Hardware or the Shark Bites from Home Depot. Yes those plumbing couplers are very expensive, but for the convenience, speed of assembly and pleasing cosmetic appearance ; I know of nothing better.

To install, you simply cut your PEX tubing to a suitable length place the white flanged tube provided with the coupler into the bare end of the PEX and then shove the PEX tube into the coupler. Leak … not a chance. The first connection I ever made was perfect. Need something to mate to the older thin wall PEX in houses built 20 years ago … no problem. Wanna mate PEX to copper pipe … no problem assemble same as PEX to PEX.

We at nuSun do not sell the Gator Bite or Shark Bite, but we do sell the solar hot water heaters that you can use to try out a DIY plumbing job and save some energy to boot.