Cold comfort in science

[wilfredjr]

Take a look down that the chart displaying the effect of temperature on performance. The baseline temperature is 50°, where 100 gpd membranes flow is 60. Does this mean outdoor operation in my northern neck of the woods is doomed? What else could be going wrong? I'd rather not save propane with the RO by using a propane heater.

https://www.amazon.com/dp/B07C3LXGSM/ref=sspa_dk_detail_4?pd_rd_i=B07GZL5GFX&pd_rd_w=Ud2io&content-id=amzn1.sym.386c274b-4bfe-4421-9052-a1a56db557ab&pf_rd_p=386c274b-4bfe-4421-9052-a1a56db557ab&pf_rd_r=2AWF95VJ01AK6M2TYGAN&pd_rd_wg=d3Qqx&pd_rd_r=d8f2f61b-b2dc-4220-b357-5d74a58a9468&s=kitchen&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&th=1

My set up is under a porch roof, to avoid sticky spillage in the garage, but the temperature seldom rises above 40° in season, and the flow very quickly drops to zilch, often popping the connectors, causing much loss and vexation. Kinda like trying to upload a reduced 586 kb image and having it faIl OVER AND OVER to a website forum. Is there a way out of this technical limit bind out of doors?
Aquatec 8800 pump, particulate filter and 3x100 (formerly 4x150, but i snapped a check valve off in a cartridge fixing leaks, and bought a huge box of 100's for the price advantage, now in doubt) are panel mount and can be moved back inside the garage, I just hate the leaks and clean-up.

I have 20 of 25 left and am reluctant to change membranes, but i will if I have to.

[Bricklayer]

Do you keep your RO indoors in a heated area when not in use ?
There is always decreased performance with the RO as you go down in temperature. It’s based on sap temperature in the membranes not the actual temperature outside. But I would not recommend using an RO outside during freezing temperatures. Bad things could happen.
I did not look at your specific membrane specs. But a 100 gpd membrane running at 40 degrees would Probley be getting like 50% efficiency. Divide 100 gallons by 24 and that’s only a little over 4 gallons an hour. Divide that by half and it’s 2 gallons per hour. You would not see a very big stream comming out your RO at 2 gallons per hour.
Are you sure there are no blockages in any of the plumbing or your valve is closed to much maybe.
How has this RO performed before. ?

[Andy VT]

With some risk of potentially stating the obvious, and correct me if I am wrong because I am still a couple weeks away from my first hands-on RO experience, but my understanding is that an RO system must never be allowed to freeze at any time, whether in use or not in use, or the membranes (at least) are ruined.
Your RO location sounds like one where it would freeze, and if so, this might have ruined the membranes.
But not sure if I read too much into it.
Hopefully this helps you, or someone else, or if I'm corrected, me!
Happy sugaring!

[wilfredjr]

Thanks for the replies. The membranes were new from the bags before they went out on the porch about noon, maybe 40°, and the needle valve was effective in getting an actual flow for about two minutes, from where it fell off precipitously to drops and droplets and then zilch by the time i got back from gathering 14 taps around the house. Two connectors had sprung atop the membranes and piddled out a days worth of sap on the ground, so I was pissed.
It's always in the thirties around here while I'm doing this, maybe low forties. In the past (3 years running RO), I would get that fall-off between batches and run a rinse, or take it back inside, I just hated the spillage cleanup. I did forget and put the check valves in the wrong cartridge hole during initial set-up the last two years, so I know what that looks like:> And no, I don't leave them out overnight: the panel mount I made is easily moved. So I guess I'm headed back inside for good!

[Andy VT]

Gotcha.
I'm in a similar situation... likely will be ROing outside much or most of the time.
I've wondered if heating up some raw sap on a little sauce pan or something and adding that to the raw sap bucket just to bring up the operating temp a bit could help.
You know, just to add extra complication and fuel usage to the mix.........

[DrTimPerkins]

It is pointless to fight physics. Physics always wins.