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Best Option for Unvented Bathroom in a High-Rise Condo

jar546

jar546

CBO
Joined
Oct 16, 2009
Messages
12,723
Location
Not where I really want to be
We have some high-rise condos that don't have any natural or mechanical ventilation in the bathrooms. No windows, no exhaust system whatsoever. Some just have that heater fan. When remodeling the bathrooms the contractors want to install fans and the owners want the fans. In these cases we have allowed charcoal filtered recirculating fans such as this one because it is better than nothing and there is really no way to vent to the exterior of a high-rise. What are your thoughts for compliance when you can't comply?

www.homedepot.com

Broan-NuTone Duct Free Wall/Ceiling Mount Bathroom Exhaust Fan 682NT - The Home Depot

Enhance your bathroom with the help of this Duct-Free Wall or Ceiling Mount Exhaust Bath Fan from NuTone. Easy to install.
www.homedepot.com
 
# ~ #

Is the exhaust fan going in to a true bathroom group,
or just a toilet & lavatory setup ?........REASON:
As I understand the reasoning for exhaust
fans, mainly they are to remove moisture, not
just odors.

# ~ #
 
Have you adopted the IPMC, or a version of it? Recirculating bath fans not permitted in the un-amended version:

2015 IPMC - 403.2 Bathrooms and toilet rooms. Every bathroom and toilet room shall comply with the ventilation requirements for habitable spaces as required by Section 403.1, except that a window shall not be required in such spaces equipped with a mechanical ventilation system. Air exhausted by a mechanical ventilation system from a bathroom or toilet room shall discharge to the outdoors and shall not be recirculated.

Install a real fan. Duct it through the outside wall, and build a chase to cover the duct.
 
The IPMC also has this section
[A] 105.1 Modifications.
Whenever there are practical difficulties involved in carrying out the provisions of this code, the code official shall have the authority to grant modifications for individual cases upon application of the owner or owner’s authorized agent, provided that the code official shall first find that special individual reason makes the strict letter of this code impractical, the modification is in compliance with the intent and purpose of this code and that such modification does not lessen health, life and fire safety requirements. The details of action granting modifications shall be recorded and entered in the department files.
 
The charcoal filter recirculation fan is permitted by code
2018 IMC
g. Mechanical exhaust is required and recirculation from such spaces is prohibited except that recirculation shall be permitted where the resulting supply airstream consists of not more than 10 percent air recirculated from these spaces. Recirculation of air that is contained completely within such spaces shall not be prohibited (see Section 403.2.1, Items 2 and 4).
 
mtlogcabin said:
The IPMC also has this section
[A] 105.1 Modifications.
Whenever there are practical difficulties involved in carrying out the provisions of this code, the code official shall have the authority to grant modifications for individual cases upon application of the owner or owner’s authorized agent, provided that the code official shall first find that special individual reason makes the strict letter of this code impractical, the modification is in compliance with the intent and purpose of this code and that such modification does not lessen health, life and fire safety requirements. The details of action granting modifications shall be recorded and entered in the department files.
Click to expand...

Right. So grant a modification or duct it outside. If you grant a modification do one for each unit/bathroom, I'm not sure I'd issue a blanket modification for the whole building.


Also, just for clarification - this is not real good code IMO. There are several situations other than high-rises where this same issue is present - fan required, no where to put it or duct it to (interior baths in old homes in particular). Water vapor from a shower and the mold it can create is a legitimate code concern, and if there's a shower present there's a legitimate argument to be made that the room should have a ducted fan; "environmental air" on the other hand isn't going to kill anyone, no matter how unpleasant it is. This code section needs a modification to say that if there's no shower, then the fan isn't required.
 
Jar I worked a lot of high-rise apartments in Broward and Palm Beach counties in the 70's & 80's as a Sheetmetal worker and never encountered a bathroom that did not have an mechanical exhaust system. Typically they where a grill on the wall into a subduct that was in a shaft with a continuously running exhaust fan on the roof. Maybe the wall grill has been removed and covered. Do you have the original plans for the building?
 
jar546 said:
Interesting but why stink up the whole condo? Humidity control I get but the odor of the watercloset use?????
Click to expand...
Agree. Also, by taking return out of the bathroom your trying to fix one code violation by creating another. IMC601.5 #7 prohibits returns in a bathroom. IMO the recirculating fan is the lesser of two evils and better than the nothing they have now, if there really is no practical way to get outside.

BTW current codes DO require exhaust in rooms with only a WC and sink. The ventilation chart in chapter 4 requires it in both a bathroom and a toilet room.
 
99.9% of condo renovations are Level 2 alterations. Not one person has brought up the Existing Building Code. Here is what it says under Level 2:

SECTION809​

MECHANICAL​

809.1Reconfigured or converted spaces.​

All reconfigured spaces intended for occupancy and all spaces converted to habitable or occupiable space in any work area shall be provided with natural or mechanical ventilation in accordance with the Florida Building Code, Mechanical.
Exception: Existing mechanical ventilation systems shall comply with the requirements of Section 809.2.

809.2Altered existing systems.​

In mechanically ventilated spaces, existing mechanical ventilation systems that are altered, reconfigured, or extended shall provide not less than 5 cubic feet per minute (cfm) (0.0024 m3/s) per person of outdoor air and not less than 15 cfm (0.0071 m3/s) of ventilation air per person; or not less than the amount of ventilation air determined by the Indoor Air Quality Procedure of ASHRAE 62.

809.3Local exhaust.​

All newly introduced devices, equipment, or operations that produce airborne particulate matter, odors, fumes, vapor, combustion products, gaseous contaminants, pathogenic and allergenic organisms, and microbial contaminants in such quantities as to affect adversely or impair health or cause discomfort to occupants shall be provided with local exhaust.
 
steveray said:
Are they actually reconfiguring the bathroom? If not, I would argue that 809.1 might not apply....Not in the work area...
Click to expand...
They often do, change tub to shower enclosure or it is part of a kitchen and baths remodel where the space is reconfigured and it is level 2 due to the kitchen or other area but the bathroom is part of that level 2 permit.
 
A bathroom is not a habitable or occupiable space by definition.

[BG] HABITABLE SPACE. A space in a building for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces.

[BG] OCCUPIABLE SPACE. A room or enclosed space designed for human occupancy in which individuals congregate for amusement, educational or similar purposes or in which occupants are engaged at labor, and which is equipped with means of egress and light and ventilation facilities meeting the requirements of this code.
 
Do that modification at your own risk. Recirculation of that air by adding a dehumidifier to the HVAC system? I'm not signing that piece of paper. JMHO.
 
Does the FBC use the IEBC? "we" don't allow anything...code does, we just accept or approve stuff...Or deny it

301.1 General. The repair, alteration, change of occupancy,
addition or relocation of all existing buildings shall comply
with one of the methods listed in Sections 301.1.1 through
301.1.3 as selected by the applicant.

501.2 Work area. The work area, as defined in Chapter 2, shall be identified on the construction documents.

WORK AREA. That portion or portions of a building consisting
of all reconfigured spaces as indicated on the construction
documents. Work area excludes other portions of
the building where incidental work entailed by the intended
work must be performed and portions of the building where
work not initially intended by the owner is specifically
required by this code.

FWIW I agree with you if there is work in the bathroom ventilation is pulled in....

809.1 Reconfigured or converted spaces. All reconfigured
spaces intended for occupancy and all spaces converted to
habitable or occupiable space in any work area shall be provided
with natural or mechanical ventilation

But maybe not in some other areas if you enforce outside of the level 2 area:

803.1 Scope. The requirements of this section are limited to
work areas in which Level 2 alterations are being performed
and shall apply beyond the work area where specified.

Not sure exactly where you guys fall...
 
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