Some Basic Questions On High Vac

[Starting Small]

I know you guys will have the answers, thanks!
-Dave

1. On a high vac system, can you have the pump and releaser on the top of a hill? If so how much will this reduce the vac. The hill would be fairly high probably 35-40 feet.
2. If the answer to question 1 is "yes" what would be the longest length mainline to run is the last 35 feet is going uphill. If answer is "no", what is the longest length mainline on flat-downhill that could be run?
3. How many gallons per day average (I know there are no hard and fast rules on this) per tap can be expected on high vac?
4. Are there other basics that I should know more about? I have read the vac section in the NAMSP manual twice. Thanks!
-Dave

[Sunday Rock Maple]

You could have the vacuum pump at the top of the hill (with a very large oversized dry line to the releaser) but not the releaser.
Figure a gallon per tap on a good day.
The best thing would be to visit a few operations in your area to get a feel with what folks are doing --- that was really what jump started my learning curve.

[Starting Small]

Interesting, so a dry line from the pump will carry the vacuum to the releaser I am assuming, and then the mainline will carry the vacuum to the whole system right?. But I would not need to run the whole woods with a wet and dry line, is that right? Are you also saying that the releaser is at the lowest part of the woods? I would be at around 200 taps. Thank you so much!
-Dave

[TheMapleMoose]

Our pump sits in the sugar house, 1000' away and 21' above one grove. 1600' away and 35' above the 2nd grove. We ran 1 1/2" pipe to each woods (Dry Line). The releasers sit in the lowest part of the woods with a moisture trap between the vacuum line (Dry Line) and releaser to keep sap from getting sucked up the vacuum line and freezing. We are also using a 30 CFM pump. We'll only get up to 1500 taps but wanted the extra CFM due to the long runs of vacuum line. the 1000' setup only has 400 taps on it, and was all we were putting vacuum to last year (with the 8cfm Airablo) so it would be a similar setup for you it sounds like. 1 1/2" line down to the releaser, and then regular mainline set up in your woods...sounds like 1" or 3/4"? Hope this helps...it works excellent for us.

[JoeJ]

My vacuum pump at the sugar house is 60' higher than one releaser and 44' above another one, both about 1,100' away.I have mainlines that are up to 900' long. (not too many taps on them) I used to have a 3 HP single stage pump that would pull 24" of vacuum. My best season 3 years ago, the trees averaged 34 gallons of sap per tap (about 950 taps). The seasons since then have not been the best weather wise. There is not as many as I would like when the trees do produce some 2 gallon per tap days, but there is a very good number of days when I get 1.5 gptap. The most important items in a good vacuum setup are large supply lines to the releaser and into the woods, a good wet/dry line set up, and of course, leak maintenance.
A good vacuum system will produce some great results. My syrup production went from .25 per tap when I started in 2004 without vacuum, to .48,.59,.54, and .49 from 2008 to 20011 ( 2012 doesn't count)after purchasing a vacuum system.

[Starting Small]

So if accessibility is an issue the releaser cannot be at the top of a hill? My problem is one area has a ton of maples but can only be reached from the ridge ofa hill so sap collection woukd be impossible if tge releaser is at tge bottom. Sounds like i should find another place to tap. Thanks
-Dave

[500592]

Just run a line up the hill and pump the sap up with a gas powered pump.

[delivron]

General Rule for Lifting Sap using vacuum.

((Inches of Vacuum * 12) - 60)/12 = Maximum Recommended Lift in feet. The - 60 is a reserve for leaks assures system reliability.

If using a reverse slop extractor. Run straight up after reverse slop extractor then slightly down hill to final releaser.

[BreezyHill]

Dave,
Send me an email and I will forward Steve Childs resent research paper that answers your questions. 1-4...and 5-10. 5-10 are those that you will have after you read the first page. Lol

I am a believer in ladders. They work, if you have enough vacuum, and pitch them correctly; while following the rules of physics for ladders. Mess up on one thing and they fail. I have a section that will be built this fall that has 52' of lift needed to get sap over a ridge that is over 2000' from the vacuum pump. Not a problem as long as mains are sized right.
Read page one carefully...the size of the pump after 800' means very little to that main; but you can use the extra cfms for other mains. This explains the major benefit to wet/dry mains.
You can also make your own cfm tester easily with a stainless pail milker, length of milk house and a valve.

Dreams keep the soul alive!

Ben