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Requirement for disconnecting a single bath exhaust fan

EricWatkins

Member
Joined
Apr 27, 2015
Messages
31
Location
Decatur Il
I'm a mechanical inspector and have never run into this. I was actually just inspecting a furnace replacement but it was done by a low-income agency contractor. The furnace was basically fine but the home owner mentioned that they installed a new bath exhaust fan (a different contractor for the same agency) and that it never shuts off. Sure enough, they hard-wired it, I'm assuming from the hot end of the light switch as it was merely a replacement of the existing. Still though, she has a legitimate complaint in my book, but I can't seem to find the right code section to back myself up before I call the contractor. Can someone more NEC-minded help me out here? Thanks!
 
Does include continuos??


Bathrooms-Toilet Rooms Mechanical exhaust capacity of 50 cfm intermittent or 20 cfm continuous


1507??
 
Last edited:
The Energy Code will limit continuous exhaust rates as the fan is exhausting 'conditioned' air.
 
$ ~ $ ~ $


Eric,

I will assume that there isn't much of an amperage load from the
lighting; in this restroom, and the inclusion of the additional load
from the Exhaust Fan probably won't violate Article 220.18
[ `08 NEC ] either...........Also, ...your application seems to be
in compliance with Article 210.23(A) [ `08 NEC ]...........Continuously
exhausting too much conditioned air is another story........This
would be addressed through the Energy Conservation Codes.

Also, ...the continuously running Exhaust Fan does not
violate the NEC.........It might, however, violate the Tiger Code
and \ or "The Annoys the Heck Out Of Me Code".




$ ~ $ ~ $
 
The Energy Code will limit continuous exhaust rates as the fan is exhausting 'conditioned' air.

The residential portion of the energy code requires a mechanical ventilation.

R403.5 Mechanical ventilation (Mandatory).
The building shall be provided with ventilation that meets the requirements of the International Residential Code or International Mechanical Code, as applicable, or with other approved means of ventilation. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

A continuous or intermittent bathroom exhaust van is just one way to meet the requirement.

Personally I do not know why someone would require/install a continuous mechanical ventilation exhaust fan in an existing home.
 
Strange if there was an existing fan, seems like would just disconnect and reconnect same wires

Which should of been switched already
 
California does have a strange rule about a 24/7 fan. It might have something to do with indoor pollutants. Apparently the indoor pollutants must be exchanged with outdoor pollutants. They end up in bathrooms with a transfer grill or a radically undercut door. I haven't inspected a new house in a long time so I don't know much about it..... It seems like a stupid idea...... so that would fit right in around here.
 
California does have a strange rule about a 24/7 fan. It might have something to do with indoor pollutants. Apparently the indoor pollutants must be exchanged with outdoor pollutants. They end up in bathrooms with a transfer grill or a radically undercut door. I haven't inspected a new house in a long time so I don't know much about it..... It seems like a stupid idea...... so that would fit right in around here.
You are right Tiger, stupidity is why we need a Tiger Code:

[B said:
"2013 California Green Code"[/B]]
SECTION 4.506
INDOOR AIR QUALITY AND EXHAUST
4.506.1 Bathroom exhaust fans.
Each bathroom shall be
mechanically ventilated and shall comply with the following:
1. Fans shall be ENERGY STAR compliant and be ducted
to terminate outside the building.
2. Unless functioning as a component of a whole house
ventilation system, fans must be controlled by a humidity
control.
a. Humidity controls shall be capable of adjustment
between a relative humidity range of < 50 percent
to a maximum of 80 percent. A humidity control
may utilize manual or automatic means of adjustment.
b. A humidity control may be a separate component
to the exhaust fan and is not required to be integral
(i.e., built-in).
Notes:
1. For the purposes of this section, a bathroom is a room
which contains a bathtub, shower, or tub/shower
combination.
2. Lighting integral to bathroom exhaust fans shall comply
with the California Energy Code

Of course you now have to look at the Energy Code.
 
Thanks so much guys! This does indeed have everything to do with the IECC. The work was done through an Illinois state program and their standards for weatherization. I just got off the phone with one of the directors of the program at the state office and I'm working my code needs against their requirements. The continuous fan, it turns out, is indeed legit so long as it has a serviceable breaker. The fan running 24/7 is causing or exacerbating other issues though with a fresh/combustion air intake without the air being tempered at all. It's dumping air straight from her attic into the rest of her house. In Illinois that means 140 degree humid air in the summer and 0 degree air in the winter. Thanks again guys!
 
Thanks so much guys! This does indeed have everything to do with the IECC. The work was done through an Illinois state program and their standards for weatherization. I just got off the phone with one of the directors of the program at the state office and I'm working my code needs against their requirements. The continuous fan, it turns out, is indeed legit so long as it has a serviceable breaker. The fan running 24/7 is causing or exacerbating other issues though with a fresh/combustion air intake without the air being tempered at all. It's dumping air straight from her attic into the rest of her house. In Illinois that means 140 degree humid air in the summer and 0 degree air in the winter. Thanks again guys!


Have to love professionals !!!

Some just take the money and do not even do minimum!!
 
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