Working on the Solar System

Not NASA's nor ESA's work exploring the solar system but rather the solar collectors used in heating the pool at the Painted Pony Resort.  To put it bluntly I made a mistake and as a result damaged 2 panels.  The system had a leak last year and after digging up the lines and cleaning out the lost fluid I could not locate the apparent leak.  I recharged the system with water and left it alone to see if time would show the leak.  The system ran fine all season never losing pressure.  So in the fall I reburied the lines and continued to run the system.  Of course once buried I began to lose pressure indicating a leak.  I kept the system running but at one point during the cold weather shut the system down and had a freeze.  So I began the process of pulling the 4' x 8' panels and exploring options.  I found ruptured pipes inside 2 of the panels and began the repair process.  I realized that while I could cut out and replace end connections any split pipes required brazing.  So I set off to learn how to braze copper pipe and after learning the fundamentals of brazing I repaired the ruptured tubes.  Then it was a reversed process of replacing the repaired panels back into the system.  After getting the repaired panels installed and recharging the system, I brought it online and started bringing the pool back up to 85 degrees.  Using the geothermal system I built was able to maintain the pool at about 70 degrees but the goal is 85.  Currently, the pool is back above 80 using only the solar system and is ready for guests.

water inside solar panel

Removing a solar panel

Repairs

SunMaxx Solar Heating System Performance

As noted in a previous post, the solar heating system has undergone some revisions. As a result of the upgrades a morning of performance measurements were collected from the SunMaxx solar heating system used to heat the pool.  Sunrise was at 7:10 AM (January 31, 2012) but the sun did not crest the mountains until about 8:00AM.  Even then the sky was overcast with high cirrus and small cumulus clouds and it was not until about 8:45 that enough sunlight penetrated the cloud cover to start the heating cycle in the solar panels.  The amount of overcast is shown below in a photograph recorded at 11:30 AM (time of reading) to visually demonstrate the amount of cloud cover. The collector temperature, pump speed (in percent of the maximum 1.5 gpm), and the temperature in and out of the heat exchanger were recorded at one minute intervals throughout the morning.  The sun would creep behind the clouds then reappear causing the pump to cycle up and down in response the the temperature fluctuations measured at the solar panels. The cycling of the pump appears to minimize coolant temperature fluctuations reaching the heat exchanger resulting from fluctuations in sunlight by slowing the flow rate when less sunlight is available for heating, note the "oc" and "s" on the graph and compare with heat exchanger temperatures.  A maximum of 127 degree coolant was produced by the panels during the measurement period, while 114 degree coolant was reaching the heat exchanger, with a maximum of 20 degrees differential across the heat exchanger.  The solar panels work well and combined with well insulated stainless steel lines which minimize heat loss across the run between the solar panels and pool house high temperatures at the heat exchanger are reached .  It is also pleasing to note that even on an overcast January morning the panels easily produce heat which can be used in the pool.

Solar collector performance

Cloud cover at 11:30 AM, panels producing 120 degree coolant and 109 degrees
at the heat exchanger.

Solar panels used to heat the pool at the Painted Pony Resort