Ok, so I have been seeing builders place the mechanical vent fan in the water closet a lot more lately rather than near the showering area. My view has been that by putting it in a water closet, the vent would have to be able to pull the steam down roughly two or three feet to get it into the water closet. this means the bathroom is not really properly vented therefore I recommend a vent be installed in the immediate area of the shower. Someone please give me your view on this. FYI, I have looked all through the IRC and can’t find anything about how far away the vent system can be from the shower.
As I see it, if it is in the bathroom, it is in the bathroom. And, no defect.
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I seem to remember a similar thread a couple years ago. I don’t think that you’re going to find it in the IRC.
I see that a lot also. I don’t get to redesign the house, it may be a less than optimal position, but as Larry says if it’s in the bathroom it is IN the bathroom. No defect.
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That is a valid point, I have just always deemed it not optimal and also, I look as the water coset as a separate room although it is located in the bathroom as a whole.
Water closet! what a silly descriptor. It actually refers to the plumbing and not the location. Why designers/architects decided to put the stink pot in a separate little closet is beyond me. There is no room for reading material; and why the separate door? Do you really want to close yourself in there with all the fumes?
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Agree 100%, as long as it is not directly over the shower since most are not rated for that.
It’s a marketing thing I think. I have seen many of these setups in huge master bathrooms. Imagine a sales pitch (think infomercial)… “Need to make stinky while your spouse is in the shower? Who wants to add an aroma like 
to the hot steamy floral fragrance 
of your spouse’s body wash? This is why we designed this quaint private space for you to take care of your business with it’s very own ventilation fan!!! Happy wife equals happy life…” 
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I see this set up often as well, and although it’s not a defect because there is a mechanical vent in the bathroom, I will suggest to my clients that an additional mechanical vent be installed in the bathroom but outside of the water closet.
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IMO, you’re making the wrong recommendation. Given that bathrooms with showers are high humidity zones, and it is recommended that the exhaust fan operate for 15-20 minutes after the shower has ended, a fan timer switch be installed for this purpose. Remember that the door should also be kept closed until the bathroom has been cleared of steam/humidity. This assists the fan with the ability to remove and exchange the air from all areas of the room, and prevent any moisture from escaping to other areas of the home.
'Nuff said!!
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That doesn’t work. Maximum wet air movement occurs when you allow the fan’s exhausted air to be replaced from a door that is ajar. Closing the door completely minimizes the air movement. Same thing occurs when a much larger forced air furnace blower’s intake plenum is blocked by an obstructed filter; less air flow.
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Bathrooms, water closets and similar spaces must have windows to the exterior or mechanical ventialtion. The setup you describe would only be OK if there was an openable window in the shower room. Otherwise, a 2nd exhaust fan would be required by code.
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That’s why its called a fart fan
And, like others have said, if its not in the code book, no builder will do anything about your “recommendation”.
Many builders put in their contract that they are not responsible to change anything based on an inspector’s “preference”.
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Can’t get any closer to the shower than that.
So long as the ventilation fan pulls from throughout the bathroom/washroom, the more important component is the fan CFM. There is a method to calculate bath fan CFM. Of course, that calculation and the fan CFM measurement is beyond the SOP of a home inspection, as is reporting the exact location of the “fart fan”.
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An we can thank/blame ourselves 
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Does not look like that fixture is UL Certified for wet areas.
Understood, my commnet was meant to be whimsical.
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Hi!
If the VENT is clear and functional, it should be performing its duty. That is to create a “VACUUM” in the room. The rest of the enclosed air in that room will migrate towards the lower pressure chamber and will be displaced by new fresh air that most likely will enter the room via the A/C Heater Duct or via the opening crack under the door, if it is close. Each commercial extractor has a design capacity to move air. All work the same, one will take longer than the other, but all will work, slower or faster. Ah! Some will also be noisier than others, but that is irrelevant to this question.
The ideal bathroom extraction system will be one with a recuperation exchanger that will connect to the dwelling’s duct system to use the hot air coming out of that bathroom to transfer that heat back into the system just taking the humidity outside. But that is the “next level” for the NetZero newer home designs.
I inspect new builds every week, all of the new construction in Florida has a mechanical vent outside the shower area and inside the water closet. It may be something that is a local area issue.
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