Results 1 to 13 of 13
  1. In new construction, was doing a walkthrough and noticed every room had a supply duct for the HVAC system except for the downstairs bathroom. The upstairs bathrooms each had one, including the separate room for the toilet in the master bath. Seems like this was overlooked, am I right?

  2. #2


    I'm not intimately familiar with building codes, but if a room has a heating or cooling load, it needs a supply. Pretty much every room has some load, made up of some or all of conduction, infiltration, evaporation and occupation, to name a few.

    It would be unacceptable to me, regardless or code.

  3. #3
    Join Date
    Nov 2005
    Northern VA
    I have a basement half-bath with no supply. Never had a comfort problem with it. That may be *because* it's in the basement with no windows in the middle of the structure.. the only heat loss is the concrete floor, and the only heat gain is the light fixture + occupant. Close enough to zero in all cases not to matter. Plus the infiltration from when the bathroom fan is run is actually going to be pulling conditioned air into the room.. nowhere for it to pull unconditioned air from.

    I understand that it's suboptimal, and if I ever remodel that room into a full bath I'd want to add a supply at that time. But I've never had the slightest problem as-is.

  4. #4
    I have a first floor half-bath with all inside walls. The bathroom has a vented exhaust fan but no other supply. Nine years and I have never had a problem although I do remember bringing this up when the house was being built.

  5. #5
    single story? install a supply. the attic makes two loads to deal with!

    Oh... downstairs?? I'd still install a supply.

    [Edited by rickboggs on 07-21-2006 at 08:39 AM]

  6. #6
    I'd add a small one. Our 1/2 bath in the center of the first floor gets stuffy if the door is closed. I was just thinking yesterday of adding a small supply.
    The posts and comments made by me are in no way affiliated with any company or organization. They are simply my personal opinions.

  7. It's on the first story of a two story, all interior walls. Manual J sez:

    Square feet 48
    Heat Load 158 BTU
    Cool Load 25 BTU

    We also have a shower in the bathroom. Does this change things?

  8. #8
    Join Date
    Aug 2002
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Originally posted by bydabeach
    It's on the first story of a two story, all interior walls. Manual J sez:

    Square feet 48
    Heat Load 158 BTU
    Cool Load 25 BTU

    We also have a shower in the bathroom. Does this change things?

    How doe Man. J ,come up with a load,ever so small,when there's no exterior surface in the room,or is it thru the floor?

    We always install one ,because if we don't, it gets questioned by someone.
    The small cfms we put into a room like that, is deduted from the cfms of the adjacent rooms,as they will end up there.

    With that small of a load ,if it has and exhaust fan,I don't think you'll have a problem.

  9. #9
    I suppose if you installed a halfway decent quiet exhaust fan with a timer or humidistat so that it runs awhile after showering or other activities are done you could live without a supply.

    I'd still want one. There's a latent load from both showering and standing water in the commode, rinse water in the sink, etc.

  10. Speaking about bathrooms. How cold/warm would you like it to be when you use the shower?

    That aside, I like the infared heat/light/ventilator gizmo's best. The IR lamps heat your body and not the room, so you feel warm when under it.

    The ventilator is turned on by an outlet box sized mechanical timer. The only difference was that I added a delay on break timer (SSAC) to keep the fan running for 15-20 minutes after the ventilator is switched off.

    Two switch boxes. One with a duplex switch, the other with a mechanical timer.

    This system does a really nice job removing the excess humidity and mold issues are almost non-existant.

    Highly recommended method. Only trouble. When someone comes to visit, and accidenly turns on the timer, the only way to turn it off is to go to the basemennt and turn the breaker on and off.

    Also consider multiple lighting sources. Entry (ceiling), vanity (sink) and nite-light (bedtime for older and younger folks).

  11. #11
    Join Date
    May 2006
    my guess it is a half bath.the only gain or lose is through the floor and is easily over come with the bath fan. don't worry, enjoy your house.
    remember, with electronics; when its brown,its cooking and when its black, its done!!!

  12. I like what Keepit said, its a small room and I would like to be "warm" getting out of the shower without heating up the whole house, and it must be cheaper to just exhaust the steamy air from a hot shower instead of running it through the whole house AC. Local heat and timered exhause work for me. Plus it would keep toxic fumes out of the central air.

    With new construction I would be making the bathroom really nice, two features I would love are a heated floor and heated towel rack. Not that easy to do it right except for new construction. One of my neighbors just put $14k into the master bath and didn't get either one, but they did like the bubble bath.

  13. Radiant heating for the floor and walls would be really nice in a bathroom. Yum!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event