Lately, most of my time has been spent getting the ground mount frame set up for the evacuated tube collector as well as getting the pumps and related equipment installed for the solar portion of our radiant floor system. And the way it felt last week was a bit of a wake up call to kick the process into high gear!!!!
The collector itself is a ground mounted system. We went with this for ease of any maintenance that may be required and the design of the house did not lend itself to have it roof mounted.
Initially, a simple footing system consisting of piers 3' deep were required, then two 4x6 beams were installed on top of the piers. Then 4x4 treated timbers were put across the beams. On those the stainless steel frame was mounted. The frame is what the header and the evacuated tubes plug into.
The tubing that circulates the glycol from the collector into the solar tank located inside the house has been in the ground for sometime. The Eco-Flex was installed prior to the slab being poured so that it could be brought in under the cement footing of the house. Shortly after the footing was poured we had a trench dug and the rest of the 85' coil was buried.
Next the stainless steel frame was erected and then lagged on to the the treated timber supports. The cylinder shaped piece mounted at the top of the frame is the header unit that I mentioned earlier.
With the frame completed I turned my efforts to getting the pumps set up inside the house as well as all of the copper tubing tied into the solar tank.
I should also mention that a 300' coil of pex tubing was looped in a trench that extended from the mechanical room and then outside for roughly 130' feet. This tubing acts as a heat dump. There will undoubtedly be times when all of the heat is not needed. When this occurs a secondary pump kicks in and circulates the glycol through this tubing. This dissipates the heat so the collector does not become damaged from the high heat that is created.
The brains of the whole unit is the RESOL controller.
The Resol has two sensors connected to it. One is in a conduit from the mechanical room out to the collector, which measure the heat being pruduced at the output side of the collector. The other sensor is near the bottom coil of the solar tank. When the output temperature is about 8 degrees warmer that the temperature at the bottom of the solar tank, the RESOL controller tells the circulating pump to turn on. This then circulates solar warmed glycol through the lower heating coil of the solar tank, which in turn heats the water inside. The water inside the tank is our domestic hot water. This hot water also heats the upper coil which has our floor water circulating through it. When the floor calls for heat the two pumps that circulate that water turn on and circulate the water through the floor and start to heat the floor which radiates the heat and warms the house. See schematic.
With all of the tubing and wiring complete, as well as the lines purged with a 40% glycol water mixture, it was finally time to install the evacuated tubes.
The tubes actually heat the glycol with a gas created as the sun hits the collector in each tube. The gas rises to the top of the tube which heats the glycol flowing through the header and then is circulated into the house. It was highly cautioned to have all components ready to go prior to plugging in the tubes due to the high heat that is created resulting in damage to the collector.
Prior to installing each tube a small amount of grease is applied to the top of the tube to help in the transfer of heat to the header.
Each tube top is then inserted into the header and then clipped in on the bottom side of the rack.
Our collector has 32 tubes on it. We finished installing the last tubes by 11 A.M. By 1:00 P.M. we were producing 121 degree heat off of the collector. This was given the fact that we already were heating our domestic hot water and had also turned on the floor heat. In other words, we probably would have been at a higher temperature if we were not trying to heat so much all at once.
Along with work on the collector we have been trying our best to get the majority of the house sided prior to winter setting in. We are making steady progress and if the real cold, wintery weather can hold of until after Thanksgiving we will be in pretty good shape!!
As I mentioned last time, we have moved into the house. I will end this post with some of the finished pictures of the inside of the house. There still remains a lot of small work to be completed but it is starting to look more like a home inside!!!
No comments:
Post a Comment