Gasoline powered or Electric Motor powered RO?

[Pete S]

We have been making syrup for about 8 years. We have made the decision to purchase an RO.

The size for us is all set and I figured that a gasoline powered unit would be the best, and easiest. I do have a 60 ampere panel in our shack, with plenty of room.

I thought I had this all figured out then was reading about running this machine at 35* minimum temp for it to work.

Now I have more questions:

1.) We're looking at an "expandable" 125 gph unit. Gas or electric motor?

2.) Must the unit be operated in a 35* atmosphere?

3.) Must the sap be at least 35* minimum temp?

4.) "What do you do to deal with the colder temps and running your RO?"

Thanks for your responses, as we hope to order SOON! (like tomorrow)

[christopherh]

I've never had a problem running mine at minimum temp. I do have a heated closet for the RO and run it in there if the temps get low. If you have 60 amp service to the Sugarhouse you'll be fine with an electric unit.

[Robert K]

I have a CDL 125 and love it, you can expand to 300 max. Some have put a single 8" membrane on it and got close to 400gph
I have mine in a insulated box with a lightbulb that maintains temp when cold, a little advice, use 2 bulbs.

[MISugarDaddy]

Not sure if you are interpreting the 35 degree temperature correctly. An RO can operate at temperatures above 35 degrees or higher without any problem. The 35 degrees may be the lowest recommended temperature for it to work efficiently or at its rated performance. We went with gas because we only had 60 amp service available and ended up using it up with other high usage things like a water heater, etc. Gas is noisier, but it is nice to not have to worry about whether the cord is long enough if you choose to move it around to different sap tanks. We also were going to go with a 125 and expand it later, but the Deer Run 250 came with a bigger motor so we thought it made more sense to spend a little more money up front and not worry about expanding it later. Good luck with whatever you choose, you will NEVER regret getting an RO.
Gary

[Pete S]

I'm sorry as I must have mis-stated my question wrong.

I was concerned that by having a gasoline powered unit, I would need to run the gasoline engine in an "environment" of "at least 35* F.

For our setup, that would be problematic. I can "store it" in our attached garage, and roll it out to the shack for use, after I heat the shack up a bit.

We are ready to pull the trigger, I just don't want to shoot myself in the foot and buy something that is just to hard to find a place to run.

Deer Run Maple is what we're looking at.

THANKS!

[n8hutch]

What is the cost difference between a Gas Powered and an electric powered unit? Would there be more upside to getting a Generator that you would have year around and for other purposes and run an electric RO off the Generator? If indeed your 60 amp service won't Handle it?

I guess I would lean that way personally but there is more than one way to skin a cat as they say.

[christopherh]

The gas powered unit should run just fine at that temp. Might be a good question for Ray Gingerich. I run mine at those temps often. My holding tanks sits outside too. When I first bought my 250, I attempted to run it off of a 50 amp generator, and it would not run. I think Ray has a larger generator for testing his units. Good luck!

[maple flats]

While a gas powered RO works fine (mine was gas initially) if you can do electric, you will like it better. Far quieter and can be run indoors. Gas needs to be set out in the fresh air to run.
The RO must be protected from freezing or the membrane(s) can be ruined, along with other parts. A post above suggests 2 light bulbs, I started with 1, then 2 and finally used 3 at 100 watt on a low temp line volt t-stat. After doing that for 3 seasons, I put in a 8,000 BTU in wall propane heater with a t-stat, way better. Mine runs off a small bulk tank (50 gal) which runs several things in the sugarhouse (that RO room heater, a finisher 2x6 size, a weed burner torch as a fire lighter, a instant hot water heater and it used to run a propane fired canner before I got a water jacketed canner) Doing up to 180-190 gal of syrup a year I only use $120-130 a year in propane.
60A will run a small RO, but as you grow you would soon need to upgrade the elec. service.
As far as sap temp, in use you can RO any that is not frozen, the Deer run RO's are rated to process the stated flow rate at 37-38 degrees, if it's colder a little less, if warmer, a little more. I'm not sure where you got the 35 degree info.
On my Deer Run, a 250, I get pretty much 250 GPH at 38 F, about 230 GPH at 34F and about 270 at 40F That's about the common extreme spread. Those figures are for when I'm running at 270-275 PSI which removes about 70-75% of the water in 1 pass. If I have over 2% sap I start boiling as soon as I get about 30-35 gal concentrate ahead. If I need more concentrate I can turn the pressure down and I get faster concentrate flow, but at a lower sugar %. I also often run a second pass for higher concentration by sending concentrate to my head tank, then when I have enough in the head tank, I run recirculate to increase the sugar %. With a Deer Run the highest you can go is about 14-15%, on units that can do higher pressure can achieve 20%+.

[VT_K9]

We have a CDL Hobby RO 250. We looked at the 125 and decided the 250 would be a better choice since an upgrade would be right around the corner. With a sap puller on 275 taps we always had enough sap to run the unit (to produce enough permeate to clean the RO). If you are at or near 250-275 taps and are looking to go bigger it is much cheaper to get a 250 sized unit than to upgrade a 125.

As far as your original question I would recommend a generator as mentioned above to use with an electric RO. Then you can keep the unit inside a warmer environment. You can also use the generator in other spots on the property for power. Also if you decide to sell the unit and upgrade further I think the gas motor would be a factor in selling the unit at a good price or just selling it.

I would recommend an electric RO with generator or, at the 125/250 size, add it to the sugar house power (I know you said you only have 60 amps). Ours runs on a 20 amp outlet, but has a 15 amp plug (following the directions for power).

Mike