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Taco Air Scoop vs. B&G IAS or enhanced versions, preference?

...and something I think about too.

The design of the "air separator" is only part of the picture. Perhaps even more important is how any air separator/scoop is deployed in the system - at the point of lowest solubility of a gas in a liquid. This would be the point of highest temperature and lowest pressure, which is best achieved by placing the separator/expansion tank in the boiler supply and pumping away from that point.

You can have the highest-tech, super-duper air separator made but if you try to defy the laws of physics, it will do no better than a $20 air scoop. On the other hand, a $20 air scoop strategically placed in the sytem as descibed above will work VERY well.


  • toolman_tim
    toolman_tim Member Posts: 8
    Taco Air Scoop vs. B&G IAS or enhanced versions, preference?

    Any objective data to show a preference for a residential hot water heat installation using either the Taco "Air Scoop" or Bell&Gossett "IAS" air separators?

    I'll be using these on a ~2 inch line, feeding an airtrol fitting on my expansion tank.

    I've looked at Taco and B&G's "enhanced" air separators, and although more technically "advanced", am not sure the dramatically increased cost is worth it in my application??

    Thoughts on the Taco vs. B&G simple scoop separators?

    Are the "enhanced" versions overkill for the average residential installation, and if not, what are the type of residential applications where it does make sense to spend several hundred more $$ on these higher end separators?

  • Ditto Jim

    I`m a fan of the B&G IAS.
    BTW Al, its not a "scoop" persay

  • the Taco or IAS air \"scooping\" fitting

    I read somewhere that ethier won't work unless you have at least 18" of straight pipe going into it.. Longer on larger pipe...
    Is that from one of Dan's books?
    So in pipingwise/spacewise, its may better to go to the other model..
    By the way... The famous Weil Mclain boilers have built in air scoop at the best place in the heating system for air removal...with pumping away...
  • Boilerpro_5
    Boilerpro_5 Member Posts: 407
    For the few dollars, the IAS is the best.....

    from my experience. The IAS works on a completely different principal than a scoop and is about the same cost as a Scoop. I use the IAS for about everything. The Inhanced units do work better, but the IAS appears to do just as good a job if given some time to do its job.


    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • I agree

    We use the B+G EAS Jr. ( 1 1/4 " ) on every boiler that doesn't have an internal air elimination tapping . It just moves the air out so much faster than a normal airscoop or even the Taco Vortech .

    But ........ I'm not convinced the more expensive device is even needed after the initial purge of air on startup and a good purge of the zones . Just being around the boiler for that first hour after startup I never hear air hiss out of the EAS . Even with monoflow zones that I know have air trapped in them .

    Anyone ever put 'em to the test ? Intentionally leave a zone or zones full of air and see if the EAS , Sprirovent , Vortech , you name it , can rid the system of air all by themselves ?
  • Hyronic myths and rumors....

    Myth number one... Microbubble resorbers remove more air than a conventional scoop/seperator. This myth is perpetuated by the MBR manufacturers. Fact: Either the MBR or the Scoop can only remove so much oxygen from the system before it hits a point of equalibrium. In a continuous circ mode, the MBR MIGHT possibly remove slightly more air than a scoop, but it is miniscule difference. In regular practice, they both remove the same amount of air, just the MBR is a faster way.

    Myth number 2... If you have an MBR in your system, it will gather ALL air from the trapped locations (by osmosis?) and move it to the MBR for proper disposal. In fact, it is rumored that these things work so well, that they could suck oxygen off the next planet :-)Ain't gonna happen in this life time on this planet. If you've got a large bubble trapped in the upper regions of a system, that bubble is going to stay there until you purge it. If you happen to be so lucky as to catch a partial pump purge, chances are that the pump will become entrained with air and stop moving fluid until the system shuts off and the air is allowed to rise up to the eliminator, then when the pump starts, the cycle starts all over again.

    As Ron Jr said, the key to success is getting a good purge in the first place. Start from the bottom, closest circuits, then move lateraly until that floor is done, then move to the next higher floor and repeat the pattern. Don't try and purge everything all at once, and don't quit as soon as you see water. Ya GOTTA get the free air out of the system.

    For newbies, I recommend the use of an empty 5 gallon bucket, placed strategically over the top of the floor drain (cover removed), and with the return hose end submerged in the bucket, you can SEE when there are no more bubbles coming out, and when there's NOT anymore air coming, out, you're done, move on... Eventually, you can tell by squeezing the hose as to how your purge is going.

    HMMmmm, sounds like a line from a BPH drug commercial...(You young bucks wouldn't understand...)

    Rumor number three: You MUST have at least 18"s of straight pipe before and after the air seperator. This statement is true if your system is running at maximum allowable velocity, constantly. In a properly sized residential conventional (non P/S) system, that condition occurs for about 2 % of the time, and by that time, all the air in the system has pretty much already been removed anyway. How many times have you seen 36" of straight pipe with an air scoop dead center of the middle...on a typical residential system. Additionally, if it were REALLY that critical, don't you think they'd mention that in the installation istructions? Granted, I've not used every seperator out there, but of the ones I have made, manufactured by respectable hydronic component companies, I have NEVER seen that instruction in their instllation instructions. Once for me (in an engineering manual). None for you?

    I've actually only HEARD of it being a problem in ONE (1) system, and I think that was on a primary loop, which would be running at max velocity all the time. I think we finally cured the problem by injections of liquid Dawn detergent. (That's another one you whipper snappers won't understand...)

    Rumor number 4, Close couple pumps must have at least 12" of straight pipe between them. I'm not certain where that rule came from. I think I remember seeing it in a Taco installation manual, a long time ago. In any case, I've seen hundreds of them close coupled, and working just fine. Seen them on drain back solar systems, closed loop snowmelting systems, open loop heating systems, and GSHP ground loop systems. Again, I think the key to good and proper operation is complete and full purge.

    Rumour number 5: I am not getting out of the human comfort business and going in to the wholesale forced error business. I have yet to meet Mr Eatherton, the wholesaler, but I think I might know who it is. Time will tell :-)

    Enjoy, learn and pass it on!

  • Cosmo_3
    Cosmo_3 Member Posts: 845
    low dough is the way to go

    I will agree with previous posts, the micro bubble resorbers work faster, but I can install a 20 dollar generic scoop on, and it will remove just as much air as a more expensive air eliminator though it may take a couple days longer to do it.

    More importantly is your initial air purge strategy during the install. I still use a concept I learned from one of Dan's books years ago, using only one boiler drain I can purge all the zones in a typical multizone hydronic system in less time than it takes me to get all my tools back in the truck after a service call.

    Try this link;


    More often than not when I use a Spirovent these days it is because of it's compact design.

  • Jim Erhardt_3
    Jim Erhardt_3 Member Posts: 80
    Great points!

    Mark makes good points. It has also been my experience that placing an "ordinary" air scoop in the right spot does a superb job. I also concur that the "recommended pipe lengths" before and after an ordinary scoop doesn't make much (if any) difference in the vast majority of systems.

    Place the scoop/separator on the supply, pipe the expansion tank/PRV into it and pump away!

    Mark, when you have a chance contact me at [email protected] - thanks!
  • Al Roethlisberger
    Al Roethlisberger Member Posts: 194
    Primary loop, max velocity, may be my application - IAS works?

    Well, I certainly appreciate all the thoughtful replies, and it is great to hear that my personal intuition seems to have been the conventional wisdom here... which is that the relatively inexpensive IAS will do just fine given a little time to do its job.

    But I do have one follow-up question:

    Mark wrote:

    "I've actually only HEARD of it being a problem in ONE (1) system, and I think that was on a primary loop, which would be running at max velocity all the time. I think we finally cured the problem by injections of liquid Dawn detergent. (That's another one you whipper snappers won't understand...)"

    In my coming application, my heating system will be the primary, boiler injected as secondary loop, plan to run 24/7 constant circ on the primary, and the air removal will be on the primary loop supply(expansion tank attached, airtrol, pumping away).

    So is there any special consideration or design I should think about with the placement or type of air removal device based on Mark's comments above?

    Just a DIY'er trying to learn, and improve and maintain his converted ca 1929 overhead gravity hot water system since there is no one local that can.
  • Joe Mattiello
    Joe Mattiello Member Posts: 703

    Check out the attached technical document TD11 put out by Taco.
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
  • Will you have any flow control valves in the system?

    Like non electric TRV's or zone valves, or will it be a wild loop with maximum flow and out door reset? If it is wild flow, then you probably should go with an MBR. If it is variable flow, then you can go with the IAS.

  • Wow

    I see alot of people have fallen off the (You must have a micro-bubbler on ever job or your doomed bandwagon.) A true saleman's web-site.
  • Jim Erhardt_3
    Jim Erhardt_3 Member Posts: 80

    Truth be known, I ran my own system for 10 years with no air automatic elimination at all! A Buderus G205, two loops of baseboard and a "loop" of 3 (old, salvaged from jobs) cast iron radiators in a finished basement. When air started making a racket in the baseboard, I would crank up the basement zone to entrap the air and vent it from the radiators. Pumping away really pushes the air around nicely!

    Since I installed a new zone of radiant for our bathroom a few months ago, I installed an air separator at the same time so I don't have to chase air anymore.

    IMO, effectively (and conveniently) dealing with air has more to do with near-boiler piping than the type of separator/scoop used.
  • Al Roethlisberger
    Al Roethlisberger Member Posts: 194
    Yes will install a Taco or B&G Flow Control/Check Valve

    Just to be sure we are talking about the same thing, I plan to install a flow control valve such as:


    ...as a flow control(backflow) on the primary(system) loop right after the circulator.

    I may have TRVs on a few key radiators through the house.

    But I think(and correct me if I am wrong) you are saying that if the IAS is going to be on a loop that is constant circ(near max), the IAS may not be the best choice. I don't think you were asking if I had a flow-check on the loop itself.

    And in my design, that is likely what will be happening. We'll have max flow most of the time through the primary loop. Even with a few TRVs, I don't think the flow is going to change much in this large volume system.

    So maybe another separator using a technique like MBR is better? I'll look into it.

    Would you consider the Taco Vortech an "MBR" that might be a good fit? I ask because it comes in the 2 inch size I may need, and is the most affordable by far compared to the B&G similar product.

    Thanks Mark.
    Just a DIY'er trying to learn, and improve and maintain his converted ca 1929 overhead gravity hot water system since there is no one local that can.
  • Your Right

    It has to do with system design (or lack there-of). This site usually promotes the latest trinkets to fix a poorly designed system. You will notice alot of the mechanical contractors on this site will then blame it on the GC for a mechanical room that was to small or some other issue in the design and build process. D&B really means (Design & Bail). When in all reality it was the the Mechanical contractor that installed the system that way.
  • Nick Ciasullo
    Nick Ciasullo Member Posts: 44
    Hydronic myths and rumors....

    I can address one of Mark's myths. The rule about a straight run of pipe in front of a closed coupled pump is not correct.

    The actual rule is: Five Pipe Diameters in front of an END SUCTION pump (closed or flex coupled). The reason is if you use an elbow directly in front of the pump, the water hits the back side of the elbow and hits the eye of the impeller with an upward thrust. This causes premature wear on the pump (or motor) bearings. If you can't run five pipe diameters, use a suction diffuser, which has straightening vanes designed to make sure the water hits the eye of the impeller directly.

    I am the Rep for B&G Philadelphia.
  • Tekkie
    Tekkie Member Posts: 58

    The things ya never think of...

    So it IS rocket science!
  • No

    It's Marketing. Just like on here.
  • That'll work...

    The Taco unit actually works on a completely different principle of air removal, but it too can be used in close quarters without the need for miles of straigh tpipe:-)

    The Vortec works on the principle of a vortex, or tangential air seperation. The water comes in at such an angle that it causes a minature tornoado (vornado) in the vortex of the tangential chamber. This vornado causes a slight decrease in pressure which enhances oxygen coming out to play:-)

    Hence, the name Vortec.

    Taco (and others) make much larger tangential air seperators as well for use on commercial jobs with REAL big pipes...

  • hot_rod
    hot_rod Member Posts: 21,841
    Micro bubble resorbers

    do tend to work faster then a plain scoop. I like them better on radiant systems that have thousands of feet of tube to harbor "tiny bubbles." Isn't that a song?

    They can also stop that errant, rouge, ball of solder or chunk of pea gravel that danced down the lines.

    All brass construction is a must have on the non barrier tube systems still being installed.

    I like the Spirovent threaded nose piece to screw a 1/2 pex FIP adapter and a drip leg to a safe location.

    Watts was working on a scoop type purger, brass construction, that could be used in either vertical or horizontal position. Clever idea.

    hot rod

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
This discussion has been closed.