Best rad vents for draining condensate?

Patrick_North

Hi all,



I've found the Hoffman 1A angled vents are terrible with holding onto condensate and quickly become "waterlogged" and useless when forced to deal with wet steam. Any votes for a vent that does well under such circumstances?

I've considered using vertical mount vents and then adding my own nipple and 45 to the rad, theorizing that this would maximize a vent's draining capability. Thought on this?



And yes, we're trying to address the root of the wet steam, but it's a slog- a much abused 2-pipe vented system in  my church's rectory.



Thanks,

Patrick

MTC

Yes,

straight vents are better at draining.



If you REALLY have a problem, and aren't going to correct the cause of the problem, you might want to tap out the holes to 1/4" and use 1/4" fittings and vents, or at least 1/4" fittings and then reduce to 1/8" right at the vent. This will allow more space for condensate/air to pass each other, allowing the condesate to drain out easier.



If you're going the fittings route, mount the vent up a bit higher off the elbow too with a short nipple and coupling/reducer to attach the vent.

Rod

Wet Steam Radiator Vent

Hi Patrick-  It seems that the Hoffman 1A has a problem dealing with wet steam. Chris J has been fighting this for a while and replaced his 1A s with Gortons. I think your idea of a couple of 45 elbows, a nipple and a straight vent has merit. I'd just try one and see how well it works.  Pex Supply carries both straight and angled radiator vents in all number sizes.  However if the steam is really wet, I'm not sure that any vent would help. Run the pressure as low as possible as this will help the water precipitate out of the steam stream.

- Rod

Patrick_North

Thanks, gents

Good thoughts all round. I'll give it a shot. Hopefully this will help buy some time as we sort out the thornier, more expensive problems in the basement.

Thanks,

Patrick

ChrisJ

Yup

I had endless problems with my 1As doing this.  I switched all 10 out for Gorton's around 2 months ago and have not had a single problem.  I wouldn't bother with straight ones, just go for the standard nickel plated 90 deg Gorton vent.



I personally don't think the cause is wet steam, I think its a problem with the vent but I'm by no means a pro at this.  One of the reasons I don't think its wet steam is the vents MUST pass steam vapor to work.  Steam vapor + cold metal = water, no matter how wet or dry the steam is.

MTC

The vents

don't pass steam vapor, that's their job, to stop the passing of steam. They pass air. They will get a little bit of condensation inside their body due to steam getting up there to close the vent, which should trickle down. Very wet steam will greatly exasperate this problem.



The Hoffman vents worked well for many decades on many systems. Unless the newer ones are poorly made (always a possibility), I would have to assume that the system changed causing the problems, before I assumed the vents were faulty.



That doesn't mean that the Gortons don't handle drainage better. They seem to do so. But perhaps the failure of the Hoffmans is more related to a system problem that should be addressed than to a design flaw in the Hoffmans, and changing them out for Gortons is a bandaid on the symptom, not a fix of the cause of the problem.

ChrisJ

MTC

I'm sorry but I must disagree with you.  There is no way the Hoffman vent (or any vent) reacts before any steam leaves the vent.  Not only this, but the air leaving the vent also has a high moisture content.  In fact, the paper supplied which each and every Hoffman 1A states right on it that small amounts of steam vapor may escape through the vent and this is completely normal.



The job of the vent is to keep a large quantity of steam from escaping, but small amounts do escape.



As for them working for many years on many systems, there is no way I could argue that fact.  What we don't know is if something on the vent changed. 



BTW, my 1As showed this problem constantly even on radiators which the steam never got near the vent most of the time.  Such as a 20 section radiator which often only heats 3 or 4 sections in mild weather.  The vent still ended up plugged by a droplet of water.

BobC

I switched to

I bought a six pack of Hoffman 1A's back in 2010 and put them on my radiators. Three of them consistently became blocked with a bit of water a few times a year. When I installed the Smith G8 I was hoping that the drier steam (better header) would solve that but it didn't.



I also suspect the problem might be that all my radiator runouts are 10-12 ft and they all have at least an inch of pitch over the 10 ft. I bought MOM's and replaced the Hoffmans and so far so good.



Both the Hoffmans and the MOM's pass a bit of steam before closing



Bob

MTC

No arguments on most of these points guys

I have heard enough problems with the 1A of late to believe that there have been some issues with them. I don't know what the cause is, but I have to assume that one of the innovators of steam systems, on a product that has been around for a long time, has some idea what they're doing. Of course, we've seen plenty of examples of their products being of marginal quality too (ahem, pressuretrols, ahem), so who knows.



I just think that the first assumption we should make when you get water plugging up a vent, is that there's too much water in the system. The fact that many other vents will operate under these conditions w/o plugging doesn't mean that there isn't something potentially wrong, or at least non-ideal.



Of course a little steam gets past a vent. Its a thermostatic bellows element in those hoffmans, or the metal piece in the gorton, that has to heat. But the air coming through right before the steam starts warming it up, and then when steam hits that element, it takes very little time to snap it shut. The alcohol flash boils at 180 degrees (if i'm remembering right), and this happens nearly instantaneously in the presence of 215 degree steam.



That steam getting in there will naturally cause a very small amount of condensation. Since the 1A has very little "air space" for steam to get in there, you would then take 1/1700th of that volume, and that's the condensate you should get coming out of the vent for each "fill up" of the body with steam that has condensed. This should be a drop at most on any given closing of the vent.



What else could it be... i dunno, rust particle getting up in there or something, maybe slowing the drainage of the vent a bit. Wetter steam creating more condensation maybe? A myriad of small things could be causing or contributing to the problem. The vent's design is also one factor. It clearly doesn't handle condensation as well as many others, but I'd be a little hesitant to say that it will consistently clog when used in proper conditions.



You said you had a few that consistently gave you troubles, did you try switching problem ones with ones that worked well (switching between radiators), to see what would happen? I wouldn't be surprised if the one that was working well in a diff rad now clogged up in this one. In that case, for some reason, that radiator gets too much water into its vent. That would indicate a system problem, albeit probably a very minor one. If, however, the problem vent continued to be a problem in the new radiator, and the one that had been working fine continued to work fine in the radiator that used to have problems, then I'd say that the vents themselves have poor quality control.



Also, none of that is to say that I'm necessarily a big fan of the Hoffman vents myself, or a disliker of the others. I like Gorton vents.



I just think that the first assumption should be that something in the system is causing a non-ideal condition, and try to figure out what that may be and why. You may still then choose to switch to another vent and leave the small problem alone, but I think its a little short sighted to assume that b/c a vent that drains at higher rates fixed the symptom, that the symptom was caused by the old vent.