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How critical is the 18 inches

zeb_3
zeb_3 Member Posts: 104
Do ya think the cost of a spirovent over a purger makes a difference in getting the job or not? My price on a job is never the lowest anyway. I always use spirovent, isolation flanges, ball valves and boiler drains on supply and return. When it comes to boiler piping I do it as if I'm coming back to work on it. So it's my way or the highway.
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Comments

  • on an airscoop

    We run into this problem all the time - no room to install the airscoop 18 inches from the elbow . This job was in a tight spot - a solar tank on the left and a garage entry door on the right . We try to keep one side of the boiler clear for access to clean the boiler and chimney . Will air just skip by if the scoop doesnt have that 18 inches ? I would hate to go the full 18 on every job , turn up , and come back with my circs and flowvalves . Does any manufacturer make an airscoop that can be installed and work effectively on a short run ? Or maybe do away with the airscoop and come right out of the boiler header with a 1 1/4 by 3/4 by 1 1/4 blk tee - with a 3/4 air vent catching the air right out of the boiler - like in my 2nd picture ? Time is of the essence with the header setup . Thanks in advance .
  • Ray M_2
    Ray M_2 Member Posts: 64
    scoop

    I use the honeywell power vents on all my installs.They can be installed right afer the elbow and work great.




    merry christmas

    ray
  • EDDIE GRIERSON_2
    EDDIE GRIERSON_2 Member Posts: 32
    Vent

    I have installed air scoops with less tha 18" and not had a problem. I use spiroventers on my upgraded systems. I wouldn't recommend the tee. The spirotherm venters are a little costly, but work nice. GOOD LUCK Happy Holidays
  • Bill NTSG
    Bill NTSG Member Posts: 321
    Ron,

    ...Sometimes I just use the air scoop as the 90°. B&G EAS
  • hr
    hr Member Posts: 6,106
    I've used them

    as tight as 6" and they worked fine. I suppose a good purge system on the inital fill makes the difference. As long as the remaining air gets carried around the systen I feel thea scoop will get it. It may take a few more trips without the 18", I suppose.

    This Watts scoop is suppose to work in either horz or vert position, which would be handy in your tight enviroments :) Probably priced betweem the cast iron scoop and higer priced micro bubblers.

    hot rod

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  • ed wallace
    ed wallace Member Posts: 1,613
    air scoops

    i always use spirovents they do not require 18 inches ive placed them 6 inches after the elbow and they still work

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  • Jackchips
    Jackchips Member Posts: 344
    Nice neat job,

    Ron. It would have been even better with a clean bucket-lol.
  • Hey

    That was just a bucket of mine I put there when we were purging . And that was a clean one . Thanks Jack .
  • Yep - excellent point

    A good purge on the initial fill - with correct piping and pumping away from the PONPC - do you think that an airscoop is overkill , on say a house with 1 or 2 zones of baseboard heat ? Thanks HR .
  • We priced the Spirovents

    and we probably wont be using them in the near future . Any idea on how well the Taco Vortec airscoops work , and how are they pricewise ? Happy holidays to you also Eddie .
  • Gonna check them out

    Never heard of it though - they arent actually powered , are they ? Thanks Ray .
  • Boilerpro
    Boilerpro Member Posts: 410
    I can understand where you're coming from....

    I have found that the B&G IAS... an orifice design.... works better than the air scoop and is the same price. Picture number 2 usually doesnt work. You need to slow the water down enough and have laminar flow (no turbulence) to allow the air to float up out of the water. If you do a set up like number two, you should increase the size of the pipe feeding into the elbow, continue it full size up and then put the vent on top and the smaller takeoff on the side. Even with this it doesn't work as well as a properly installed air separator. I try to keep the pipe as long as possible and use the IAS or, with a bigger budget,maybe an EAS. This is why I wish they were still casting air separators in the boiler. Hydrotherm still does, and maybe Weil. Burnham stopped, Dunkirk doesn't on most, except the Quantums.

    Boilerpro
  • Beautiful work Bill

    That B and G airscoop looks like one heavy duty piece of equipment . Looks expensive too .
  • Most of our jobs

    even 6 inches is too far . I wish someone would make an airscoop that mounts in a vertical run .
  • What I was thinking

    was using an 1 1/4 Y tee , in place of that 1 1/4 by 3/4 by 1 1/4 tee . I would install the Y upside down , so that the flow naturally goes to an air vent at the top of the
    Y , and the circ takeoffs would be out of the side branch of the Y - using a 45 to straighten it out of course . Do you think this cockamamie idea would work better than pic number 2 ? Thanks Boilerpro .
  • Floyd
    Floyd Member Posts: 429
    Have used...

    the Vortec and am very happy with it.
    They use a 3/4 tapping on the float vent... seems to help also....
    I think they are around 100 bucks.... pretty cheap insurance......
    one call back you don't have to make and it's paid for.

    Here's a job that I used the Vortec on.


    Floyd
  • Yep

    We used the 3/4 vents on a commercial boiler with a standard Taco airscoop , and they vent a hell of alot faster than the 1/8 inch version .
  • Great work Floyd

    I envy the room you have to work in also .
  • The cost does make a difference

    Especially when its almost not needed - if you purge the system completely on install . Our pricing is never the lowest also , but Im definitely not gonna push for a piece of equpment that is more than likely over $250 , when its not absolutely critical on most heating systems we work with . Im in routine contact with our service department , and they tell me on newer boilers piped correctly - but without an airscoop - they very rarely have to bleed the system of air . I can understand having it your way or the highway , I guess . But we wouldnt turn a job down because the customer didnt want the airscoop .
  • heatboy
    heatboy Member Posts: 1,468
    You may not need either.....

    one, Ron. I notice you use high mass boilers for your retrofits. If there is a 1/2" tapping on the top for an air vent (most have), just use the boiler as your air seperator. Works as well, or better, than most other options. Spirovents and others like it are vastly over-rated. With a little imagineering and piping prowess...........

    Warm Regards,

    hb

    "Expert in Silent Warmth"™

    888-UB-COMFY

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
    heatboy



    The Radiant Whisperer





    "The laws of physics will outweigh the laws of ecomomics every time."
  • Tom M.
    Tom M. Member Posts: 237
    good point

    Good point, Heatboy. In the picture of the Weil McLain above, there is a vent in the air tapping on top of the boiler. The Burnhams have a relief valve there. I think it would be OK to put a tee there with a vent out the top and a nipple and elbow for the relief valve out the side.

    In my opinion, there is no better place for a vent. The water is moving slowly through the large boiler passages, it doesn't get any hotter, and if the pumps are on the supply side, the pressure will be increased through the piping, leaving the boiler at the lowest pressure while the pumps are running.
  • Boilerpro
    Boilerpro Member Posts: 410
    Definitely better

    If you're in a pinch, but I'd still try to get an air separator in there. By the time you buy the fittings and put it together, you probably could have bought a B&G
    EAS with the 90 degree connection built in (just like the B&G cast iron flow control valves). The EAS also includes a nice big 3/4 inch air vent, no extra charge, and allows you to connect the compression tank off the top to help keep system debris from collecting in it and causing the bladder to fail.


    Boilerpro
  • Art Pittaway_2
    Art Pittaway_2 Member Posts: 80
    I'm amazed

    that no one is talking about velocity. BoilerPro said he upsizes the IAS, but why? It's the velocity that makes the difference!! Very seldom do I ever recommend a line size separator. Go to the next one or two and increase the pipe size for the foot or whatever you have room for before you go into it. Get out a chart or SystemSyzer and look it up.
    10gpm in 3/4"=6.5ft/sec, 1"=3.8, 1 1/4"=2.5, 1 1/2=1.8, and 2"=1ft/sec. If you think about draining condensate from a steam main, only in reverse, the exit for condensate is full pipe size up to 6" and one size less on larger mains. The Air Scoops are a convience item but I'm not sure all are well thought out. Study the old condensate drainage piping arrangements and think about air going up. I still laugh about the post a few weeks ago with the separator in the vertical pipe. Great picture.
    Art
  • zeb_3
    zeb_3 Member Posts: 104
    Ron Jr.

    In my area a 1 1/4" Spirovent sells for approx. $125. I've serviced many systems w/o a seperator or a scoop w/o much of a straight run before it and there was always air issues. I found the spirovent & pumping away to work the best. I am fortunate that I am able to install the way I want.
  • hr
    hr Member Posts: 6,106
    I agree

    Johnstone Supply sells 1/1/4" air scoops for $12.43. They also have the same sized Spiros for $119.58. Good old cast iron air scoops have worked fine, in most cases,for years. The key is properly places purge valves and a few coin vents on the higest baseboards. Why argue with sucess!

    There are places in "modern hydronic" piping arrangements where spiros have a place, however. The secondary loop that a injection mix system pumps into is an excellent spot. Very often the air in the radiant loops doesn't want to cross the VS bridge! A spiro in that side will make life much easier for noise free operation, I've found.

    ME has an interesting theory about micro bubble resorbers, they may be too much of a good thing :) tell us again Mark.

    hot rod

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  • Tim_12
    Tim_12 Member Posts: 14


    I have to say great job, not often do you see a contractor doing a new install performing an efficiency test , Great job!! For the 18" I was told that the air scoop is useless if it is not there(18") I would talk with Taco or whoever is the mfg. Good luck and Merry Xmas!!
  • John Abbott
    John Abbott Member Posts: 355
    Scoops?

    I use Weil Mclain WGO series cast iron oil fired boilers almost exclusively.I use the 1/2" tapping for air removal and it works great for fin tube or convecter systems.I think this is because I pump away from the boiler and the top of the boiler is the area of lowest pressure making the air bubbles larger and more buoyant and also it is the lowest velocity in the system giving the air more time to rise.Also it is the hottest water in the system which has the lowest capacity to retain air.
    This is not done as an economy measure it's just unecesary for these applications.We do only do high quality work all of our installations have ball valve and boiler draains on each side of each heating loop valves On each side of the boiler feed valve and a gauge cock under the hy vent so we are not eliminating the air scoop to save money it's IMO not nescesary.

    John
    On radiant or any systems with primary secondary piping I use the Spirovent and have found it to be much more effective than the others I have tried

  • jim f
    jim f Member Posts: 182
    boiler piping

    heres how i pipe a tight boiler still maintaining 18" on scoop
    jim f.
  • heatboy
    heatboy Member Posts: 1,468
    Are these available yet?

    I saw the first prototype a few years ago and have been waitng for them. The local Watts rep is a client of mine and has told me they aren't ready yet. Can you get them, hr?

    My best to you, Ellen and Max!

    Warm Regards,

    hb

    "Expert in Silent Warmth"™

    888-UB-COMFY

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
    heatboy



    The Radiant Whisperer





    "The laws of physics will outweigh the laws of ecomomics every time."
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    I'm

    thinking along these lines..What is the average life of Hyvent on a scoop (talking well water here)? 2-3 yrs? I must have changed hundreds of them. One or two service calls like that, and the Spirovent has paid for itself.

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  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    Microbubble resorption and other hydronic myths...

    Greetings to all, and Merry Christmas.

    I work quite closely with a large group of forensic engineers and scientists from all over the country and the world, and one of them tested the overall efficiency of microbubble resorbers versus conventional air scoop type of air seperators. His findings were quite interesting. What he found was that both of them eventually dropped the free oxygen content (the biggest enemy to proper circulation) to the same levels. The MBR got it to the lower limit quicker, but BOTH devices worked to the same degree in getting the free oxygen down to a point of benign neutrality. MBR's attack the dissolved oxygen content and can actually make the system water oxygen deficient, or oxygen hungry. Ma Nature hates imbalances in oxygen content, and will do anything she can to balance the oxygen contents out, through rubber gaskets, valve packing glands, expansion tank diaphragms an so on and so forth.

    Another interesting nugget of information that he found was that when the system circulator was off for an extended period of time (summer), the dissolved o2 levels rose back to a point of equalibrium. In other words, why super remove the dissolved oxygen from the system unless you are guaranteed constant (24, 365) circulator operation.

    I've been doing without MBR's for going on thirty years, pumping away and using conventional air scoops and I've never had a problem, until I did my own house and installed a MBR. As I relayed just recently, there was a bubble working its way around my one pipe system for almost three years. The MBR could NOT get it out. I finally injected 2 fluid ounces of liquid dish detergent into my system and the bubble is now COMPLETELY gone.

    MBR's were originally introduced to address air problems that could have been avoided or eliminated with proper near boiler piping, I.E. pumping away from the PONPC. While they were effective in addresing that nagging problem, I've found that a properly pipe, properly flushed and set up system will work PERFECTLY well with a conventional scoop type of air seperator.

    As for the 18 inches of straight pipe in front of an air seperator, you'd think that if it were REALLY all that important, that they'd include those written instructions with every seperator they sold. I've NEVER seen ANY instructions requiring 18" of striaght pipe before or after the seperator. None, Zip, Nada, ZILZCH. I have seen it in their engineering specification information, but not in their INSTALLATION instructions.

    Think about this also, these simple air seperators work based on fluid velocity. How often is a heating system operated at its maximum velocity. 2% of the time, maybe... The rest of the time, it is oversized (including the air seperator) for 98% of the time.

    I just finished installing a large (3,000 Sq. Ft.) snowmelt system using a conventional air seperator, and I DID allow for the 18" of straight piping in front of the seperator, because this system WILL be operating at maximum flow whenever it is on.

    Space heating wise, I do not think it is as critical, and in many cases have had 2" of straight pipe in front of the seperator on space heating systems and have never been called back for an air problem.

    Guess I better not hold my breath waiting for the MBR manufacturers of the world to ask me to write an article on the benefits of their products eh... Sometimes, the truth hurts.

    Happy Holidays ya'll!!

    ME


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  • Arthur
    Arthur Member Posts: 216
    Boilers vents & expansion tanks

    Hi Floyd.
    Yes nice looking job. however I couldn't see how your expansion tank was piped in, I've always made a practise of piping the expansion tank direct (no Valves)onto the boiler as the boiler (a Heat generator) is going to be the source of any expansion in the system, If the rest of the system is isolated from the boiler. The rest is not going to expand,
    Had a job just recently were I was invloved in a secondary capacity to a another heating company. Now the plans drawn up in Germany said the expansion tank was to be on the return to the boiler now the firm had piped it up on the flow.The owner was doing a moan about it but I said it didn't matter as long as it was connected to the boiler direct with no valves between it and and boiler and the hot water from the boiler could not get to the tank.
    Whats the general feeling from all you guys about this ?
  • Arthur
    Arthur Member Posts: 216
    Boilers vents & expansion tanks

    Hi Floyd.
    Yes nice looking job. however I couldn't see how your expansion tank was piped in, I've always made a practise of piping the expansion tank direct (no Valves)onto the boiler as the boiler (a Heat generator) is going to be the source of any expansion in the system, If the rest of the system is isolated from the boiler. The rest is not going to expand,
    Had a job just recently were I was invloved in a secondary capacity to a another heating company. Now the plans drawn up in Germany said the expansion tank was to be on the return to the boiler now the firm had piped it up on the flow.The owner was doing a moan about it but I said it didn't matter as long as it was connected to the boiler direct with no valves between it and and boiler and the hot water from the boiler could not get to the tank.
    Whats the general feeling from all you guys about this ?
  • ScottMP
    ScottMP Member Posts: 5,884
    I have to agree with Mark

    I don't have the engineering info that Mark has, but a properly designed system would not need to have a MBR.

    Pumping away Alone, should eliminate the need for one.

    One of my suppliers allways trys to sell me one. "Don't need it".

    I did attend a class a few years ago from Taco where they explained the 18" theory. I make sense to me that the water is turbulent coming up the riser and would need the 18" to allow the air to rise to the top pf the supply pipe. I would belive that over a period of time all the air would be eliminated if the distance to the scoop was shorter. I don't like to see a close nipple, but if we can only get 12" or so, for a neat job I allow it.

    Mark , great info on the MBR's. I had a job that constanly had air in it ( old system, that a friend bought ), we installed a Spirovent. ALL the air went away. SO DID all the air in the old expansion tank. We installed a diaghram tank and no more problems. I told that the MBR removed so much oxygen that it would absorb all the air out of the old steel tank. Mark's info shows that to be correct.

    My Opinion .... Nice product ..... Don't really need em !!

    Scott (18" inches) Milne :)

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  • really now.....

    Geeze ME,

    all this time I thought an airscoop was there to remove air.. not absorbed oxygen :-) The absorbed O2 will dissapate by working with the ferrous products in your system. If they were to remove oxygen maybe we should have called the absorbed oxygen removers.

    Air Eliminators (air scoops, spirovents, sparco/honeywells, B$G, Taco) are only to remove air.. and they do it quite well. Yes, the AIR gets absorbed by the water and removed by the air eliminator (and other factors). Yes air containe oxygen.

    Air Scoops work on removing bubbles that were formed by air coming out of solution from being heated. (physics 101, gas has a higher absorbtio rate in a cold liquid). SO the boiler heats uo the water, air comes out of solution, air goes to highest point (in the scoop) and goes out the air vent. Note that the 18" (which is on all the instruction sheets that are in all the boxes of air scoops on my shelf) is so that the water is no longer as turbulant and the air can settle out in the eddie created by the raised part of the scoop.

    All the other air eliminators work great in the hot side but also work well on the cold side (return) of the boiler. This is because they use physics 101A, (lower the pressure, lower the solubility). They all create some sort of a drop in pressure (vortex swirl, ventury) and have the air chamber on the low pressure side.

    I sing the praises of Spirovents for multiple reasons. They were the first air elimination divice introduced here in the USA to compete witht the old air scoop (see T for hanging expansion tank on page 3). Then, becuase the Spirovent worked so darn well, we saw no less then 5 competitors arrive.

    In MY OWN TESTING I took my own heating system (30% fin tube, 30% convectors, 40% radiant) and lowed by DeltaT's significantly. The system hadbeen in for 3 years and on the rfh loops the best I could achieve was a 30 degreeDeltaT. I installed a spirovent on a BYPASS and within 3 days was down to a 5 degree deltaT. Adding the spirovent was the only change I made. I installed it on my existing bypass between two valves so I only introduced about a pint of fresh water.

    I was very sceptical. After my own experience I obviously sing the praises for the Spirovent. I sell a ton of them. I have never had a disatisfied customer (except the guy who installed the horizontal version on the verticle pipe).

    ANd now I am raising my prices because I sell them for a lot less then you have all quoted here :-)

    wheels
  • hr
    hr Member Posts: 6,106
    Here's what we need to demonstrate

    Some 1-1/4" clear tubing, like on the Weil steam demo trailer. Then we can test and compare the air, and or O2 removal. Put in a schrader valve, to pump in shots of air, like the Spiro vent demo you see at trade shows. Then we sit and watch :)

    I will admit the Spiro and other brands with screens or whiskers inside do attract those tiny bubbles better.

    On a test bench this multi poised Watts scoop seemed to perform better in the vertical position when some sceen type mesh was stuffed inside!

    Maybe an exercise schedule on the pumps during the summer months would be a good thing for all systems, regardless of your purger preference. I know it would have saved some snowmelt freeze up caused by glycol seperating over the summer :) Probably would be good for the pumps life also.

    hot rod

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  • Dan Schaffer
    Dan Schaffer Member Posts: 6


    Bell & Gossett's IAS requires 6 pipe diameters upstream and 3 pipe diameters downstream. This may be advantageous for some installations.

    best regards,

    Dan Schaffer - Bell & Gossett
  • Glenn Harrison
    Glenn Harrison Member Posts: 405
    What about the EAS?

    Any special piping requirements for the EAS?

    Glenn Harrison Residential Service Tech

    Althoff Industries Inc. Mechanical and Electrical Contractors

    Crystal Lake, Illinois
  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    Actually...

    I made a large visual demosntrator that never made it in front of a jury that did exactly what you said, except that it had two pumps, an air scoop, an expansion tank, and a clear section of tubing that did a 360 degree loop. It also had four very large pressure gauges at each corner to demonstrate what happens when you don't pump away, and what happens when you do. It was VERY graphic. We'd get one of the pumps running and inject air into the loop, and it would disappear. Then we'd switch pumps and do the same thing. I'll take a picture of it next time I'm at the college and post it for everyone to see.

    ME

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  • Mark J Strawcutter
    Mark J Strawcutter Member Posts: 625
    might be a good idea

    to include this info in the installation instructions.

    Mark
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