Announcement

Announcement Module
Collapse
No announcement yet.

Venting A Bathroom.

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • Venting A Bathroom.

    The first floor level bathroom, in our home, was constructed (before we bought the home) in the middle part of the floor plan. As such, there is no window. Neither is there an exhaust fan. A couple of years back, we hired a mold inspector to come out and access the situation. It was his finding that there indeed was mold, showing where the plastic shower enclosure met the top of the tub - but that it was 'harmless' mold. Now, I had never, ever heard of any such thing as 'harmless' mold, but took his word for it, at the time. However,I had become increasingly concerned about the matter - especially after seeing how this mold situation has seemed to have gotten even larger.

    My aim is to tear down that shower enclosure; address the mold buildup, and redo the shower area with ceramic tiling. But, before that, I need to address the very probable reason (no exhausting) that the condition took foot, in the first place. I need to install a bathroom exhaust fan,and would hope to get some answers to the following questions:
    .................................................. .................................................. ........................................

    1). Can ducting be run at a horizontal line, to the outer wall?

    2). If the answer to #1 is in the affirmative,would it be OK to give the outer wall extension a 90 degree elbow downward? Or should it be elbowed up?

    3). I would think that rigid ducting would be best, but what are the opinions on flexible ducting?

    4). The bathroom, in question, is 18'x 8'. What would be the minimum size exhaust fan that I should go with?

    5). Also, what would be a very good brand to go with?
    .................................................. .................................................. ........................................

    I offer many thanks,in advance, for any and all info to be given to this request.
    ~Blessings~

    Nathan

  • #2
    Re: Venting A Bathroom.

    if you have mold with fg wait until you put in tile. google fantech. your right venting needs to be first. i take it that you have a second story? #1) yes. #2) yes, in fact there are covers that you can put on the outside to keep out insects and rodents. which is a nice touch. #3) i use insulated flex duct. much quieter. if i was putting this in a soffet, then scd 40 pipe. #4) go to fantech look around and see what you need. the info you need is there. #5) fantech. #6) yes a dehumidistat. #7) if it is a long run which yours sounds like well a timer with the dh. it will keep the duct dry.............you may end up with 2 fans. this job is outside the box, get creative. have fun. breid...................

    Comment


    • #3
      Re: Venting A Bathroom.

      Your goal is 8 complete air changes per hour. Your bathroom is 8 x 18 and assuming 8 foot ceilings, and has a volume of 1152 cubic feet. Take the cubic feet and divide by 60, which is the number of minutes in an hour, which gives you 19.2 and multiply by 8 (air changes) gives you 153.6 CFM. It is always better to round up so, a 200CFM fan would give you the capacity you need. Alternatively, for bathrooms over 100 square feet, you could allow 50 CFM for each fixture (toilet, standard tub and shower) and 100 CFM for a jetted or whirlpool tub. You may want to consider an inline fan where you could put multiple inlets in and have only one fan motor. If your house is two stories, you could exhaust the fan through the rim joist of the second floor. Regular flex duct should work fine in that case. If the home is one story, you could put the fan motor in the attic with two inlets in the bathroom connected with a 4" wye. Vent with insulated flex duct through the roof. An inline fan has a powerful motor and remotely located, will be whisper quiet. Nutone, Broan and Panasonic all make good units. The lower the number of sones, the quieter the fan will be. Consider putting the fan on a timer so it can shut it self off 10 to 20 minutes after you have left the bathroom.

      Comment


      • #4
        Re: Venting A Bathroom.

        Thanks Breid, and Killavolt.

        You both have imparted some very helpful information, andi really do appreciate you two. I will probably give it a tad bit of overkill (CFM wise), as I am REALLY concerned about combating this situation effectively enough, so as to insure against a resurfacing of the mold & mildew.

        Another matter is the fact that I will be attempting this job myself. I have never given effort to such a task, before, and am trying to research everything I can, on it. I am just on the heels of dealing with a contractor who didn't honor his contractural obligations, on our garage roof, and the respective monies, laid out to him, will be held up until such time as the matter can be litigated in court. Naturally, I am really gun-shy, now, about hiring anyone else.

        As already mentioned, I don't know the first thing (yet) about installing a bathroom exhaust fan, and ducting, but love working with my hands. I just recently ordered a DeWalt Inspection Scope (due here, tomorrow), to help me to see what's behind walls, and such. I am also going to be doing some other renovating, a round here, so the scope will serve many more applications than just the current one.

        Breid, I don't know about running anything up under a soffit. Being that this will all be virgin lands for me, I need to keep things as straight-forward, and as simple as possible (lol). Our home is a two-story structure, and I don't know NEARLY enough to warrant making a vertical run through the roof. I will have to take the straightest, horizontal run possible, out to the side of the home.
        ~Blessings~

        Nathan

        Comment


        • #5
          Re: Venting A Bathroom.

          Originally posted by killavolt View Post
          Your goal is 8 complete air changes per hour.
          I learn something new all the time on this forum.

          Comment


          • #6
            Re: Venting A Bathroom.

            Originally posted by Flux View Post
            I learn something new all the time on this forum.
            Indeed. There are some VERY Knowledgable, and truly helpful folk here.
            ~Blessings~

            Nathan

            Comment


            • #7
              Re: Venting A Bathroom.

              I hate to bother everyone, again, with this issue, but I just ran across some information (on installing a bathroom fan) which leads me to ask yet another question.

              The attached Jpeg references a screenshot, from information at a website. Under item #1, there is an advisory against installing the vent no more than 6ft from the fan. The distance from the intended location of the fan, to the outside wall, is greater than 6ft. In fact, it will be more like 12-13ft.

              I HAVE to get a fan in this bathroom, and would like to know what I might be able to do.
              Attached Files
              ~Blessings~

              Nathan

              Comment


              • #8
                Re: Venting A Bathroom.

                Contact Broan I'm sure they have a fan that will do what you want. All you have to do is go to their website & send them an email. Also the mold on your tub is from lack of cleaning. Mold needs food to grow & fiberglass is not it. I surprised you don't have mold on the ceiling. When you tile use cement backer board with a waterproofing membrane. I use Kerdi. Make sure you run the duct parallel with the ceiling joists.

                Comment


                • #9
                  Re: Venting A Bathroom.

                  Originally posted by MR.FUDD View Post
                  Contact Broan I'm sure they have a fan that will do what you want. All you have to do is go to their website & send them an email. Also the mold on your tub is from lack of cleaning. Mold needs food to grow & fiberglass is not it. I surprised you don't have mold on the ceiling. When you tile use cement backer board with a waterproofing membrane. I use Kerdi. Make sure you run the duct parallel with the ceiling joists.

                  I have to disagree with you on a statement in your quote. 'Lack of cleaning' may very well be a high, probable cause for such conditions. But that, certainly, is not the case with us. Numerous times have I tried to combat what's happening with all types of cleaning solutions - even frequent spraying with pure bleach. In all honesty, the growth hasn't been extreme, but enough to let me know that the spread is greater than it once was.
                  ~Blessings~

                  Nathan

                  Comment


                  • #10
                    Re: Venting A Bathroom.

                    Referencing that JPEG, you will never get a 4 inch fan duct through a hole cut with a 4 inch hole saw. Go with a 4 1/4 hole saw. We regularly run fan duct more than 6 feet. Try to keep the runs as straight as possible. Some good websites will tell you to increase the CFM of the fan to compensate for longer runs/bends. I have never seen mold/mildew grow ON fiberglass. I have seen it on walls, ceilings and especially silicone caulk.

                    Comment


                    • #11
                      Re: Venting A Bathroom.

                      Originally posted by killavolt View Post
                      Referencing that JPEG, you will never get a 4 inch fan duct through a hole cut with a 4 inch hole saw. Go with a 4 1/4 hole saw. We regularly run fan duct more than 6 feet. Try to keep the runs as straight as possible. Some good websites will tell you to increase the CFM of the fan to compensate for longer runs/bends. I have never seen mold/mildew grow ON fiberglass. I have seen it on walls, ceilings and especially silicone caulk.
                      Oh, Killavolt, How could you question that JPEG? It was from Home Depot--and we all know that we don't question their experts! :-) I am sure glad I didn't see that before I put in my fan--I couldn't have one in less than 6 feet.

                      Comment


                      • #12
                        Re: Venting A Bathroom.

                        Originally posted by Pipestone Kid View Post
                        Oh, Killavolt, How could you question that JPEG? It was from Home Depot--and we all know that we don't question their experts! :-) I am sure glad I didn't see that before I put in my fan--I couldn't have one in less than 6 feet.
                        Oh my goodness! I didn't even notice that. Imagine me criticizing someone with their knowledge and expertise.

                        Comment


                        • #13
                          Re: Venting A Bathroom.

                          Just a thought on your first question. Depends on the direction of your ceiling joist. I guess all are assuming(very dangerous) that the joist run perpendicular to the outside wall. If they are parallel you have other issues to consider.

                          Comment


                          • #14
                            Re: Venting A Bathroom.

                            that was why i suggested a soffit. to box it in below the ceiling. breid.............

                            Comment

                            Working...
                            X