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Steam vs hydro air for allergies

Erki Member Posts: 3
My wife's allergies seem to act up every time we turn on our steam radiators. A pro once explained that the radiators may push out dirt (rust, other particles from the old pipes) that could be causing the allergies to flare up. I'm considering switching to hydro air as we could add filtration and potentially improve the situation, but from what I read, forced air (including hydro) may actually increase allergies due to the ducts gathering dust and other unsavories, and due to the dust that can be kicked up by the air streams.

Has anyone converted from steam to hydro air to deal with allergies and what has been the experience? Any other words of wisdom (other than the usual "you'd be crazy to get rid of steam no matter what").



  • LarryC
    LarryC Member Posts: 331
    Dirt on the radiators?

    Another possible explanation is that the air currents set in motion by the heated radiator, is lifting dirt that was sitting on / behind / below the radiator and sending it airborne.  Try blowing air under the radiator and see how much dust and dirt goes airborne.

    A different possibility is that the radiators have something on them that outgasses when the radiator is heated.  Was the previous occupants smokers or were the radiators painted sometime in the last several years?
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Try this first

    I am presuming that your system is one-pipe, and not two-pipe

    Are your radiator vents hissing a lot during heating? If so, then they may be expelling more than their fare share of the air in the system, due to the inadequacy of the main vents. Put a few gorton #2's in place of each of the vents you now have. The result would be that most of the air in the system will escape into the boiler room as the system is starting up.

    Was the boiler ever properly cleaned and skimmed, after its installation, or have any chemicals been added. Only pure water, with no additives should be used in a steam system, unless there is a specific water chemistry problem to overcome, and even then pure water should be chosen out of preference.

    A good low-pressure gauge will show you if the pressure is too high while running, which elevates the radiator surface temperatures above the levels of comfort.--NBC
  • Erki
    Erki Member Posts: 3
    Response to LarryC

    Thank you for your response. I will check for dust - I'm sure it's not super-clean, especially between the vent holes facing out into the room from the top part of the radiator. They were painted a few years ago with latex paint (had been painted with oil before).
  • Erki
    Erki Member Posts: 3
    Response to Nicholas

    Thanks for your response. Only one of the radiators hisses, some of them not getting warm at all (likely cause - when the boiler was replaced a while ago, they did not repipe, and now the air is forced past one of the junctures). We do have adjustable valves that can be dialed up or down, so I will try that on the one that hisses. I do not believe the boiler has been cleaned (since we moved in 6 years ago), but we're not adding anything to the water. 
  • BillW
    BillW Member Posts: 198

    First of all, what is your wife allergic to?  Only an allergist Doctor can tell for sure.  Radiators "radiate" heat, and while they may cause some convection by heating the air immediately around them, they are designed to warm you, not the air.  That said, they do collect dust, pet hair and lots of other "crud" behind, in and under them, but usually, dust bunnies and such are far too heavy to be picked up into the air in your home by any convection current.  Any volatile chemicals in the paint should have off-gassed a long time ago, so I don't think that is a contributing factor.  Do you have pets or house plants?  Pet dander and plant pollen do circulate on air currents, and could be a problem for your wife, as can other microscopic air-born allergens.  Hydroair uses a hot water coil with a fan blowing air thru it, just like any other forced air.  You can apply mechanical or electronic filters to such a system, as well as humidifiers and UV anti-germ lights. Before you do anything radical, have your wife's allergies checked out by a Doctor.  You can leave me a message at the "Indoor Air Quality" page on this site, or here. I hope you find this useful.
  • Patrick_North
    Patrick_North Member Posts: 249
    Steam is best.

    My daughter and I have lousy allergies- she worse than I. The allergist we see said that steam or hot water radiators are far superior to forced air when it comes to keeping household allergies in check, and my experience agrees. We had forced air in our last home (with plenty o' high tech filtration) and my dust allergies etc. were worse there.

    It's not that you can have air filters with such systems- it's that you must have them to attempt to counter the dust storm! Even if you filter the system air you can't stop the registers from blowing around particulate in the room.

    If your wife is reacting to the dust caught by convection currents it's a big help to dust those radiators with a damp rag. We avoid using chemical dusting sprays because of the smell when heated. As we renovate our home we've been powdercoating radiators and find that as a side benefit this makes them a breeze to keep clean and dust free. A lot cheaper than converting to hydro air, too!

    Good luck,

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