Anyone using a Spirovent for air removal?

I have been getting some "free radical bubbles" as I like to call them in my system when the temps get into the 185+ range and a good load on the boiler with a 20+ delta. I think I'm having some boiling on the firetubes and the cooler return water releases the bubbles rapidly. These bubbles seem to travel right through my CI watts air scoop as I think they are too small to rise into the air chamber and be exhausted through the air vent. I've bled the vent to be sure it is not fouled and all is working well and no air out. Saw a system with a Spirovent and looked them up, they seem like they would capture this type of micro-bubble and coax it out much better than a plain old scoop. Just wondering if anyone had some expierence with tme or the Caleffi version.

BTW, I've raised system pressure to 25psi at full system temp and adjusted the expansion tank, this did help some but boiling still happens and the bubbles collect in the radiators on the second floor..........

http://www.spirotherm.com/air/animation.aspx


TS

I'm using the Junior with 1 1/4" threaded model (VJR125) since late last season. It is working as advertised from my observation. I still have the Watts air scoop connected at the output of the boiler where it connects to the primary loop with an auto vent and the small expansion tank under it. I installed the Spirovent on the high point of my primary loop and intend to connect the bottom to my large homemade expansion tank when I christen my storage. I know in the past I would hear air (water sounds) occassionally in the pex for several days where it exited through the floor whenever I made a piping change, added a thermowell, or did something that introduced air into the system. I would check the autovent on the Watts scoop each day and it would have a small amount of air to release. This season I've had to fix a leak, clean a y strainer, and drain the boiler during a week vacation which I'm sure had to introduce a small amount of air into the system. I have noticied any air (water sounds) at all since the Spirovent was installed so I would have to assume it is getting the microbubbles and anything bigger out much quicker than I was doing in past years with the autovent. In hindsight I probably should have replaced the Watts with the Spriovent so that it always saw the hottest water coming out of the boiler but it seems to do the job where it is at now.

Hey Taylor. That is a nice demonstration of how these things work in the link, thanks for putting that in your post. I have one of those in my primary loop just after my oil boiler entrance. This is also after the the Wood Gun, but much further away. Here are two pics, first is right above the Wood Gun, second is just above and to the left of oil boiler after it joins into the primary loop. The only thing I can tell you is I have not had any problems with air. How did you know you had micro bubbles in your rad.?

I took out my watts and installed a spirovent 3 years ago and am very pleased with its performance.

My air trapping and separating has been working great - and it's been partly by design & partly by accident.

I had a scoop & vent already on my supply line just before the zone valves. I just left that there (replaced the vent with a new one). I put two more vents in high spots on my backup boiler loop right above that boiler, and my sidearm loop. I also shimmed my storage tanks so that one end is just a bit higher than the other. If air gets past the vents & thru the piping, it ends up in the tanks & floats up to the high spot & sits there until I bleed it through a ball valve I have there. I caught a lot for a while that way.

The accidental part is on the new boiler. The hot water supply exits the boiler up high on the side (i.e. not out the very top). And I had a regular old non-bladder expansion tank strapped up in my floor joists above the old boiler. I just left that there and T'd that into the blow off tapping on the top of my boiler, just for the extra expansion place. But what I found happen is these little bubbles you're talking about that form right where the water is heated (the exchange tubes), gather & rise up to the top of the boiler, and every once in a while when firing hard there will be a gurgle and the air will rise up through the piping into the expansion tank. So that expansion tank is collecting most of the air that is being forced out of the water, and it's not getting out of the boiler into the system piping since that tapping is just below the top of the boiler.

All that air action has decreased since I started burning this unit, so I don't get much of it anymore. I got caught once early on not bleeding my storage tank soon enough (even though I could hear it gurgling every time I was down there), and some of the air there got sucked into my piping which introduced an air pocket into one of my zones and some serious head scratching when that zone stopped heating (thought my zone valve motor went bad). And I had to bleed some air out of the expansion tank once as the fluid level in that circuit was almost down to the top of the boiler, with all the air it was catching. So that old expansion tank turned out to serve more good as an air catcher than an expansion tank.

BTW, I'm still only running around 8 cold/12 hot system pressures, and everything is working like a quiet little top in my two story system. Couldn't be happier with the boiler & overall system performance.

My spirovent doesnt seem to be catching much of anything. I am still purging air out of my system from last year by opening the AutoMag valve for my overheat loop that I put an autovent on. I dont seem to have any problems in the system elsewhere, and my makeup water has been manually valved off, so not sure where the air is from, but the spirovent doesnt seem to be getting rid of much of it....

This is interesting, I've had my system filled and working (with this boiler) for3 months and I get these micro-bubbles whenever I fire and temps are up. MY old boiler (with same piping setup) never did this after the initial air was out. I think this is due to the firetube design and much greater heat transfer from those hot surfaces. This "air/steam" will travel through the piping up and down and through circuits, which makes me believe it will not rise sufficiently in the air scoop to collect and be automatically purged. It will collect in the elbows that head down in the radiator circuits and make water like noises due to the low flow circuits. They will eventually flow and end up in the boiler return only to pass right by the air scoop and go around again, this is mhy I think I'll have a better fighting chance with the Spirovent in place of the Watts unit. I snagged one from ebay, I'll sweat it in when it gets here.

TS

I'm having a hard time understanding this. If you're talking about steam bubbles from kettling, then that is not "air" in the system. Those steam bubbles condense into water as soon as they cool below the boiling point, which happens quickly. If the hotter water is having the effect of somehow freeing up air that otherwise is in or is getting into your system, then a spirovent type device will remove that air until it is all gone, and then it is done. A system when it cools down that does not have enough residual pressure will create a vacuum and that will suck air into the system from any available place, and that air then will "materialize" when the system is again brought up to temp. Vaporized water, whether from boiling, cavitation or otherwise, still is water and condenses back to water.

i have a spirovent on my oil burner side and a scoop on my wood boiler side. the spirovent is the way to go! i have five zones and a bunch of baseboard---that thing will bleed out almost any amount of air. a friend of mine grew up doing hvac and plumbing in mass.---when he saw my system with the spoirovent, he was blown away---he said they used them on every system up there--he was shocked to see someone down here using them, as most guys use the cheaper air scoop. he said his pop would be able to bleed out a whole apartmrnt bldg. with a spirovent overnight.

I installed one near my wood boiler and it worked like a charm. The one I use was the vertical mount type since I didn't have the head room to install the normal horizontal type.

I have a watts scoop and auto vent by the oil boiler and it works but seem to take forever to get the air out and I had trouble with the auto vents fouling too. You can take them apart and clean them but it seemed to take almost nothing to either make them not vent at all of not shut off.

The Spriovent worked quickly at getting the big stuff out and after a week seemed to get all the little stuff out too (you could hear the circulator growl every now and then).

I read a lot of reviews and people seem to like them. They're also not suppose to foul, which I'm not as worried about now that I have everything flushed but still something to keep in mind. If it wasn't going to be a big pain I would put one by my oil boiler as well. Not cheap but they seem like a nice product.

K

This is what I was thinking as well Jim, If I have just the primary pump on and no loads calling, I just have water circulating through the boiler and the primary loop round and round. Now if I open the ZV for my big indirect I get a bood amount of cold water mixing in with the primary loopr returning to the boiler. There is no air in the indirect's coil as it's directly below the primary loop. When I open this valve and this is when the "bubbeling" happens. It seems as though the cooler water all of a sudden hitting the firetubes somehow releases these little bubbles and then I hear them coming out of the boiler's supply and through the pump and so on. Wait a few minutes for eveything to settle down and it stops. My radiators in the room directly above the boiler room (master bed) will make little trickeling noises in the elbows that lead back down to the boiler room as well indicating there is some air trapped there as well. I flush out said loop and it goes away only to come back next boiler fireing. I'm going to remove the Watts scoop altogether and replace it with the Spirovent and connect the expansion tank to it as the Watts now is. I'm thinking if I catch the little bubbles before distribution and vent them.

TS

Thought I'd do a follow up and put in a plug for Spirotherm Ind. This works very well, I can hear bubbles once and while and they never make it to the circulator which is pumping away from the air vent. This thing works well, much better than the CI air scoop design, which would have let those bubbles through. Every now and then, it hisses out some more air as the top collects enough for the float to fall.


TS

One thing I really liked about this unit was you can put the circulator on either side and there's no real minimum run either. They're really forgiving and work really well.

K