This winter the weather cooperated for our freezing challenge and stayed well below freezing in December. Our freeze/thaw stress test went from December 16th 2016-January 4th 2017.
In order to freeze our system, we drained the system entirely of grey water and wash water using our air driven plumbing, gravity and a shop vac. We also removed our membranes and stored them in a cooler.
Greg took photos of the cabin the day we drained the water and shut off the heat using an infrared camera and when we returned from holiday.
We also filled our 15 gallon waste water keg with grey water and left it on the porch to freeze (see featured image).
This is what happened when we came back 3 weeks later, re-installed the membranes, turned on the space heaters and filled the water tanks back up:
There was enough soap residue in the grey water tank for the soap removal pretreatment to start making bubbles with he fresh replacement water.
We filled the system with Anchorage tap water. There was no flood. The water tanks were all intact. Treating the water over to wash water went smoothly as well, no major leaks in any of the lines; we had one small leak, from a cracked brass fitting to a valve.
The electronics and batteries turned back on.
The keg of grey water took a week to thaw sitting in our cabin. There is no damage done to the stainless steel keg.
We took certified wash water samples after the system thawed, please follow the links to the results (PS all are equal or better than our project requirements):