Bath fan/light switching

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deckscrew

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I'm a GC in San Francisco Bay Area. My client has a bath/heat/light combo in a small bathroom. The heater will be on a timer. They would like the light and fan to be switched on together. The inspector says the light and fan have to be switched seperately. Is the inspector correct? They're thought is that it's a bathroom used by their kids and when they shower they'll turn the light on, but forget to turn the fan on. Thanks
 
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GoldDigger

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deckscrew said:
I'm a GC in San Francisco Bay Area. My client has a bath/heat/light combo in a small bathroom. The heater will be on a timer. They would like the light and fan to be switched on together. The inspector says the light and fan have to be switched seperately. Is the inspector correct? They're thought is that it's a bathroom used by their kids and when they shower they'll turn the light on, but forget to turn the fan on. Thanks
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Ask your inspector to show you the code section.
In many areas the building code at one time did not allow the light to be switched on without turning on the fan too, if the bathroom required mechanical ventilation.

The only issue I can think of would be if the energy code required the light to be automatically switched off by an occupancy sensor while the fan must continue to run separately until it automatically switched off based on a timer or humidity sensor.
Note that Panasonic and possibly others offer a fan/light combo that has a built-in occupancy and humidity sensor. That would automatically turn the fan when the kids were using the shower and leave it on as required afterward until the humidity was OK again. Don't know if they have that with an integral heater too. If not, you can still wire an external humidity sensor in the switch box to turn on the fan portion of a standard heat/light/fan unit.

Another way to address your clients concern would be to have two switches, one which supplied power toward both the light and the fan and a second in series with the light only which allowed you to turn it off and leave the fan running.
That would take care of insuring the fan was on when the room was occupied but also allowed you to leave the fan on to deal with stink or humidity and still turn the light off.
 
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GoldDigger

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curt swartz said:
CA Energy Code requires bath fans to be switched separately from lights.
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Thanks for the definitive info Curt.

That still leaves a number of ways that the client could force the fan to come on when needed, even if the kids are careless or clueless. They will just cost more. :)
As I recall, automating the fan is also either required or strongly recommended by the Energy Code or some other applicable code.
 
dereckbc

dereckbc

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Perhaps you worded some of this wrong. Is this a Exhaust Fan, Heat and Light Combo? Although not required in NEC, but by design you would want 3 switch circuits using a dedicated 20 amp circuit. No problem putting exhaust fan and light on one switch, but heat needs its own. Would not want it on in summer. Well take some of that back as I just went through this. Dedicated is required when a heater and motor are involved, but be dang if I can find it right now. I had a inspector bust me for it a few weeks ago on a remodel in my house.
 
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PetrosA said:
That's plain silly.
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Not completely. Imagine all of the energy saved by not running the CFL light in the bathroom an extra 15 minutes just so you could leave the fan running.

A requirement to have separate switch legs running to/from the fan unit would have made even more sense, since it would allow all sorts of independent control without necessarily having to install two manual switches. :)


In my parent's house near Santa Rosa, built circa 1975, the powder room (guest facility with toilet and sink only) had only a single switch and the fan was very noisy. Since only one run of NM came from the fan and the separate light out to the single gang switch box at the door, I built a small electronic module that plugged between the fan motor unit and the receptacle inside the fan enclosure.
When you turned on the light switch, both light and fan came on, preserving the original functionality. But when you flicked the switch off and back on, the fan was locked out until you left the switch off for more than 5 seconds.
I thought about marketing it, but the Tuit never showed up. :happysad:
 
PetrosA

PetrosA

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GoldDigger said:
Not completely. Imagine all of the energy saved by not running the CFL light in the bathroom an extra 15 minutes just so you could leave the fan running.

A requirement to have separate switch legs running to/from the fan unit would have made even more sense, since it would allow all sorts of independent control without necessarily having to install two manual switches. :)


In my parent's house near Santa Rosa, built circa 1975, the powder room (guest facility with toilet and sink only) had only a single switch and the fan was very noisy. Since only one run of NM came from the fan and the separate light out to the single gang switch box at the door, I built a small electronic module that plugged between the fan motor unit and the receptacle inside the fan enclosure.
When you turned on the light switch, both light and fan came on, preserving the original functionality. But when you flicked the switch off and back on, the fan was locked out until you left the switch off for more than 5 seconds.
I thought about marketing it, but the Tuit never showed up. :happysad:
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I still think it's silly. You need like 12.5 20W CFL bath fan lights on for 15 minutes to even reach one kW/h. If they were serious about energy savings in California or anywhere else in the US for that matter, they would require gravitational exhaust systems like they do in Europe and many other countries since the fans use more power than the light nowadays. In the 14 years I lived in Poland I never once saw mold growing in a bathroom - ever, and no electric exhausts.

It's also silly when you think that in spite of the serious water shortages in CA, you can still install water guzzling shower systems with multiple sprays using 10 or 20 gallons per minute - as long as you can afford them. But don't leave the CFL on with the fan... We need to save the world!
 
kwired

kwired

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PetrosA said:
I still think it's silly. You need like 12.5 20W CFL bath fan lights on for 15 minutes to even reach one kW/h. If they were serious about energy savings in California or anywhere else in the US for that matter, they would require gravitational exhaust systems like they do in Europe and many other countries since the fans use more power than the light nowadays. In the 14 years I lived in Poland I never once saw mold growing in a bathroom - ever, and no electric exhausts.

It's also silly when you think that in spite of the serious water shortages in CA, you can still install water guzzling shower systems with multiple sprays using 10 or 20 gallons per minute - as long as you can afford them. But don't leave the CFL on with the fan... We need to save the world!
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:thumbsup::thumbsup:

Not to mention the energy used heating that water as well.

I was not in the Navy but was in the Army and had cases where we had to take "Navy" showers. For those that don't know this means run a little water to wet yourself, turn water off, lather yourself, then turn water on to rinse, and do so as quickly as possible, mostly as a courtesy to your buddies so there may still be water when the last few get to the showers.
 
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