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Hot Forced Air - stale air / dry mouth

Ed2010Ed2010 Member Posts: 7
Recently converted an old steam boiler with radiators into 2 hot force air system with humidifiers and air cleaners (one for the 1st floor and one for the 2nd floor). I am now feeling that the air quality is poor and experiencing dry mouth every time the units are on.  I contacted the installer and they adjusted heat switch one notch down, closed some dampers and increased the both 1st and 2nd floor humidifiers settings but it still doesnt help!   At this point I'm thinking of possibly putting back the old steam boiler and radiators but not sure if it would be a mistake.    I'm open to any suggestions.   Please help! 


  • JStarJStar Member Posts: 2,668

    Welcome to forced hot air.

    What are your humidifiers set to? What do you mean by "heat switch one notch down"?
    - Joe Starosielec
    [email protected]
  • BrianBrian Member Posts: 237
    What's involved in putting it all back?

    Can you say a bit more about where the old steam system is? Is everything still connected? On the way to the recyclers? Out in the garage?

    Could the stale air be due to needing a new filter? I'm asking because whether you have forced air or steam, you still have "stale" air in the house.
    1929 Ideal Heating vapor system.
  • SteamheadSteamhead Member Posts: 11,378
    It was a mistake

    to abandon the steam system. Now you can see why. Put it back in service if you can. Use the ducts for A/C only. 
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Gary ReecherGary Reecher Member Posts: 111
    Try steam humidifier?

    What type of humidifier is installed?


    Forced fan?



    If you don't have a steam humidifier have your installer switch to that style. They are capable of producing more humidity than other types.
  • Jamie HallJamie Hall Member Posts: 6,696

    it was a mistake to take the steam heat out.  If you can put it back together, do.  And, as Steamhead says, use the ductwork for airconditioning.

    Whether that is still feasible or not is another question, which we can't answer (as Brian said, where are the bits and pieces?).

    On the "stale air" problem, not surprised at all; while it is true that -- again as Brian notes -- you may have "stale" air with steam, it is usually not so much of a problem as it is with forced air, if only because there is usually more infiltration.  With forced air, however, I have found that unless you have an absolute minimum of four air changes per hour of outside -- repeat, outside -- air, you are going to have a problem with air quality, pretty much with any financially feasible filtration system (I know, the Space Station doesn't have outside air -- but do you want to pay for their air quality control system?).  In the bad old days this was taken care of by infiltration.  Nowadays, with all the caulking and sealing and what not that folks put it, you have to have a dedicated and controlled fresh air intake.  In the interests of energy conservation, it should have at least a sensible heat recovery heat exchanger (I'm not keen on latent heat recovery exchangers, for a variety of reasons).

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Bob LBob L Member Posts: 16
    Stale air

    I am with everyone in regards to their love of steam. That being said I feel forced air gets a bad wrap the same way steam gets a bad wrap and that's because of uninformed techs. Many service people screw up steam systems with improper piping and lack of knowledge about steam. The same goes for forced air. There are many things that can be done to achieve proper humidification and air quality. Unfortunately air to air heat exchangers and proper sized humidification and properly sized ducts are not the norm. Things like multi-staged with variable speed can go a long way to reach very comfortable indoor air. To answer your problems would take knowledge of what is currently in your house (photos would be of great help..the more the merrier). Many simple things usually can be done to help, like putting the humidifier on hot-water instead of cold, you can set blower setting differently. Insulating the ducts can in some situations be a big benefit. The humistat location may be wrong. The list can go on and on.The board here can be a great help, please don't get discouraged as there is surely a way to achieve the desired comfort to which you strive for.
  • Ed2010Ed2010 Member Posts: 7
    Hot Forced Air - stale air / dry mouth - old boiler/radiators

    Thanks everyone for your responses.  My house is an older house ~1930s and the radiators were recessed radiators built into the walls.  My house has approximately 2500-3000 square feet of living space and has an unfinished basement, a 1st floor, 2nd floor, and a small attic (not finished and barely has room to stand).   The old steam boiler is still in the basement but disconnected.   All of the old steam pipes in the basement have been cut and removed, however the pipes leading up to the rooms are still buried in the wall.     The radiators were removed and stored in the garage.  The holes where the radiators stood have been sheet rocked.  I'd imagine that if we were to put the old system back we'd have to twist out remaining cut pipes and re-thread new pipes into the elbow connections which are still sitting on the basement floor joints, then re-run the gas lines, hookup the water feeder again, put back the exhaust pipes,  and last but not least put back the radiators...but obviously would need an expert to evaluate this.
  • Ed2010Ed2010 Member Posts: 7
    edited March 2010
    Hot Forced Air - stale air / dry mouth - new system details

    I have two systems installed.  One in the unfinished basement and one in the attic.    Each system has a Luxaire 95% furnace model # TG9S040, an Aprilaire model 5000 air cleaner and a humidifier.   I have two types of humidifiers, in the 1st floor I have an Aprilaire 400, and on the 2nd floor I have an Aprilaire 700.  Everything is brand new installed within the last month.  I've attached the pictures for both the 1st floor furnace (located in the basement) and the 2nd floor furnace (located in the attic) 

    The 1st floor humidifier is installed on the furnace and has a humidifier control on the main trunk. (see picture) 

    The 2nd floor humidifier is installed in a closet (as I did not want it installed in the attic) and power vented to the supply intake (picture attached).  I've had issues with the humidifier turning on at due to the outside humidity and as such installer disconnected the outside sensor and put the unit on manual mode.   As you can see in the picture the humidifier control reads 56% and thus did not turn on when I turned on the heat this evening.    Within 10 minutes I felt the dry stale heat in the room and felt my mouth dry up.   Its been almost 1.5 hr since i turned off the unit and even after drinking two cups of water my mouth is still dry.

    My house is a center hall colonial with around 2000-3000 square feet of living space.   The first floor has 6 rooms and 1 bathroom.    The installer installed 2 vents in the living room 12x21, 2 vents in the dining room 12x12, 1 vent in the foyer 7x12, 1 vent in the kitchen 11x9, 1 vent in the eat in kitchen 7x10, 1 vent in the den 5x13, and 1 vent in the bathroom 4x6.   All vents in the first floor are located on the floor.  The supply intake is in the basement near the furnace.   The second floor has 3 rooms and a bathroom totaling ~1000 square feet.   The installer installed 2 vents in our master bedroom 15x14, 2 vents in the 14x17 bedroom, 1 vent in the 12x13 bedroom, and 1 vent the the bathroom 10x6 with one supply intake in the middle of the 2nd floor near the stairs.   All vents in the upstairs were located in the ceiling.   I believe that there is also 2 PVC pipe that go to the outside of the house for each furnace (this might be for the intake and exhaust as well)

    The installer changed the heat setting for the upstairs furnace by adjusting the factory setting for the "heat switch one notch down".  This may be just a jumper setting but I don't know the details of what he did. 
  • TechmanTechman Member Posts: 2,144
    edited March 2010
    stale air

    Sorry about your old steam heating system.But the new condensing furnace should run pretty well anyway. Check the humidity  level in the room's and see what you have compared to the 'stat setting. 56% is a high setting ,35-45% is more normal. The type of humidifiers that you have work only when the heat is on and it takes hours and hours to bring the humidity levels up to normal,if they are low. Check into the steam type of humidifiers as suggested,but expect an increase in your utility and water bills along with healthier living conditions.Some steam humidifiers require cold water input,not hot water,just check first, pardon the word but "steamers" require the indoor blower to energize while steaming.And check the location of the steamer in the ducts ,most go in the supply trunk.Utilize the outdoor sensor also on the steam humidifier .
  • JStarJStar Member Posts: 2,668
    Wrong Location.

    First floor humidistat is in the wrong location. Right now it is downstream of the humidifier. That means it will satisfy as soon as the furnace blower comes on. You need to have it moved to the return. Personally, I always put the humidifier on the return, and the humidistat as far upstream on the return as possible, while still sensing every return in the house. Usually, that means, the humidifier is about chest high, and the humidistat is a good foot higher.

    Second floor humidifier is in a closet? And the duct run for it goes to the return ceiling box? That seems kind of sketchy. But the installers also didn't make a return plenum on the furnace so it would be hard to run that supply duct to there.

    When you look at your system, try to think about where the humidity wants to go, and where the humidistat is sensing the air.
    - Joe Starosielec
    [email protected]
  • Gary ReecherGary Reecher Member Posts: 111
    Oh me, oh my, oh no

    First Floor Furnace:


    Humidistat located downstream of humidifier. Installation instructions require that be located on the upstream side of the humidifier. Relocate to the return duct upstream of the 6 inch pipe from humidifier. At least 6 inches away from that pipe not between the pipe and the furnace.

    Electronic Air Cleaner:

    No support at base on outer housing to prevent torqueing of case. It's in the installation instructions.

    Are there turning vanes installed in the return to the air cleaner?

    Gas Shutoff:

     Located downstream of drip leg tee.

    Second Floor Furnace:

    Air Cleaner:

    There needs to be a tapered box on the inlet of that filter. Dead heading the return right at the filter is going to result in improper airflow across the filter.

    Get rid of the flex. the sharp elbowing results in drastic reduction in airflow. Flex duct on its own has twice the resistance to airflow vs metal pipe even when properly installed. This is not.

    The air cleaner needs to be moved away from the return of the furnace and a transition duct to taper from the outlet of the filter to the furnace return.



    Mounted in closet. On to what? The sheet rock wall? Very hard to tell from photo. Then feeds the outlet into the return box. Where is the humidifier getting the air from the closet? As this is a forced fan humidifier. Your first floor humidifier is an air bypass type.  Humidifier control should be mounted in the living space.

    Very poor install.
  • Ed2010Ed2010 Member Posts: 7

    The 2nd floor humidifier is mounted in a linen closet (which has a closed door).  The humidifier is located on the top shelf of the linen closet.   If you look closely at the picture the bottom white board is the top shelf.   The humidifier control is actually in the closet and the water lines are tapped into the shower water lines thru a plumbers access door located at the bottom of the closet.   The closet sits directly in front of the shower.

    Air seems to be sucked into the humidifier from within the closet and vent up thru the ceiling of the closet and back into the supply intake (see previous picture)

    Do you think that I might be getting the stale air/dry mouth because of a bad install?
  • TechmanTechman Member Posts: 2,144
    dry air dry mouth

    These humidifiers only put moisture into the air when the heating unit is fired up,not justwhen the thermostat is in the heat position.No heat no humidity,these Aprilaire units are in the "bypass" family requiring the heat  to be fired up.
  • Ed2010Ed2010 Member Posts: 7
    steam humidifier

    Assuming that the humidifiers are the issue and I upgrade to the steam humidifiers.   Would I need to install one upstairs and one downstairs?  Also where is the best place to have them installed?   Near the furnace in the basement?   Upstairs in the closet? 

    Thanks again for your help.
  • SteamheadSteamhead Member Posts: 11,378
    Well, with the piping and rads still there

    It can be done.

    Try the Find a Professional page of this site to get your comfort back.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • JStarJStar Member Posts: 2,668
    Steam Humidifiers.

    I've had really bad experiences with the Honeywell TruSteam. They need to be cleaned almost every week. And they require a dedicated 15-20 amp circuit.

    You should be able to make your system work. It just needs to be installed correctly.
    - Joe Starosielec
    [email protected]
  • TechmanTechman Member Posts: 2,144

    I tend to agree with JStar about trying to see if the existing systems will work,but if they don't.Go steam! The new Honeywell TruSteam units are self cleaning,they require cold water, they might also require an inline water filter ,depending on your water condition and they get installed in the supply air trunk[,the air leaving side of  the furnace]and they do need a dedicated power outlet 115v 15a.And if a condensate pump is used to get rid of the little bit of waste cleaning water then the pump must be rated for 212*
  • hydroheadhydrohead Member Posts: 7

    Return air being drawn from the furnace area? Duct the return to the living area.second floor will work much better with a separate return in each bedroom.GeneralAire DS35 is the best steam humidifier available on the market.
  • Ed2010Ed2010 Member Posts: 7

    What is the best configuration for the steam humidifiers.  Would I need 2 of them?  or just one?   I dont want to install one in the attic so I'll have to put it in the 2nd floor somewhere.   What options do I have?
  • Ed2010Ed2010 Member Posts: 7

    I've had several comments already indicating that the returns are not properly installed in the basement and in the attic.     Do hvac systems typically need to have a return in every room?   What are the benefits to doing this?   Would this be the reason why the house air seems stale and dry?
  • TechmanTechman Member Posts: 2,144

    1 or 2 depends on the size of the area being conditioned in comparison to the ammount of humidity in gallons you need and how many gallons the humidifier  produces in 24 hours.Having return ducts in each room depends on your living style, are all of the doors closed most of the time ,blocking the regular flow of air around the house?If yes, than yes.
  • Ex Maine DougEx Maine Doug Member Posts: 160
    Returns all over....

    Whem my wife and I designed our house in Olando FL, we specified insulated ducts (no flex) for the entire house with a return in every room.  We dropped the size of the unit by 25% and had both good air circulation and temperature balance in the home.   Here in Baltimore we see row homes where the system is in the basement trying to push cold air up to the third story above the basement. Does not work. 

    The right kind of ducts in the proper locations make the world of difference.  Steam heat is better.

  • GerryEGerryE Member Posts: 3
    Geez Guys

    You're all missing the most important thing the homeowner said! " The return is drawing from the basement! " I hope it's realy loose and there are no other gas fired applinces in it! ! ( especially a water heater)  The stale air syndrom could be caused by the furnace blower drawing air into the basement causing  excessive infiltration, high humidity and if a water heater is present carbon monoxide problems . GET THAT RETURN FIXED FAST!!!
  • GordyGordy Member Posts: 7,122

     A good duct design for a furnasty uses PROPERLY SIZED returns in all rooms except kitchen, and baths. You are pulling everything from the basement. Thats not good, basements tend to be dustier, radon gas, and creates negative pressure for combustion appliances. Unless they recieve the combustion air from an outside source. If not you will stavre them of combustion air decrease their draft, and pull flue gases in the basement, and through the home via the return in the basement. Get it fixed.

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