Taco Vortech versus 4900 Air Separators - Are they for different applications?

Al Roethlisberger

Other than their maximum recommended velocity differing by 3ft/sec, Taco doesn't seem to have any documentation that clearly defines in what applications the 4900 and Vortech air separators are best suited.



Their catalog documentation even lists both in one brochure, and the descriptions seem very similar touting both as "enhanced" air removal, but providing no matrix or guidance on how/why one might choose one product over the other.



<a href="http://www.taco-hvac.com/uploads/FileLibrary/100-2.9.pdf">http://www.taco-hvac.com/uploads/FileLibrary/100-2.9.pdf</a>



I'm just curious what application each is best suited for, or is one clearly(or marginally) simply better.  The pricing is also very similar for both, with the 4900 commanding about a $20 premium.



Al

Mark Eatherton

They are different paths to the same point...

They can both only remove the O2 levels in water to a certain point. The one with the rings in it MAY do it faster than the Vortec, but bottom line, they both stop at the same train station in the end.



10 or so years ago, numerous manufacturers introduced "microbubble resorbers" in response to a perceived problem in the field, that problem being, air in suspension in older heating systems. The theory was, if you put an MBR in, it will remove all free and entrained air out of the system, thereby allowing for a very quiet operation. True to their claims, these devices work as advertised, however, during periods of non circulation (summer) the O2 levels go back to a saturation point, and when the systems are first started in the fall, air noises can be heard.



In reality, the reason this perceived problem is present, is because of the pumps location in regards to the expansion tank. If the pump is pumping away from the PONPC, it has no choice but to present its pressure differential capability as a POSITIVE pressure, which keeps small bubbles small, moving them around to the air recovery/elimination system.



During a trail that I was a part of, we had a group in San Francisco do tests on MBR's versus conventional air scoops, which are significantly less expensive than MBR's, and the lab found that the MBR's did in fact de-aereate the water faster, but that both units essentially brought the O2 levels down to the same point, in relatively short order.



With that said, I have used the conventional cast iron air scoop for 30+ years successfully, with ZERO problems, but I pay critical attention to the location of the pump in relationship to the expansion tank.



One distinct difference between scoops and MBR's is that if the air is moving towards the air separator in a violent/turbulent fashion, its removal efficiency suffers, hence the recommendation of significant straight pipe before and after the scoop. In todays mechanical closets, space is a premium, and the MBR's do not require ANY straight pipe before or after the separator, hence you can pipe in and out of it with street els' if you so desire.



The cost differential that you are seeing is due to materials of construction. Brass is more ex$pen$ive than cast iron. The reason they came out with the brass item is in response to all the people who got sucked into using non oxygen barrier tubing, which will cause the cast iron unit to dissolve.



In the Good Ol Days, the best place to remove O2 was right at the boiler. THis was where the temp was the highest, pumped pressure was the lowest, and the O2 had a propensity to come out of suspension.



Times they are a changing. These days we pump TOWARDS the boiler, but still away from the PONPC.



Now, you know more about MBR's scoops and air elimination than you wanted to... :-)



ME

Al Roethlisberger

Indeed...

..... I wouldn't say "more than I wanted to know", but certainly is a fantastic explanation.



I really do appreciate your taking the time to write that explanation.





I guess one final question would be:  Would it be OK to install a 2" Vortech on a 1.5" line?  I've already got a 2" on hand, and it almost seems like jumping a size would potentially increase the efficiency of the unit by decreasing flow  *shrug*



Al

Mark Eatherton

No problemo....

Other than having to round up the reducers...



You CAN"T run the water through an air eliminator TOO slow ;-)



ME