Bathroom venting

[John Cahill]

I seem to recall an old code that allowed bathrooms to be vented with an X number of air changes from the HVAC system. Can someone educate me? I know what new code requires.

[Brian A. MacNeish]

Originally Posted by jcahill

I seem to recall an old code that allowed bathrooms to be vented with an X number of air changes from the HVAC system. Can someone educate me? I know what new code requires.

The Home Ventilation Institute recommends a fan capable of 8/ach for a bathroom. I don't remember seeing a figure for a general forced air HVAC system. Does anyone have a copy of ASHRAE 62.....I can't find mine at the present and have to run out.

[John Cahill]

I am reaching back into the 70's or 80's. I could almost bet a steak there was an allowance for HVAC air exchange in lieu of a window or exterior fan. Perhaps it was a local thing or I got hit by lightning.

[Jeffrey R. Wicklander]

Saying that there are air changes involved with the HVAC system means that there would have to be a return in the bathroom. This should not be allowed.

Jeff

[Mark S. Tyson]

Originally Posted by jcahill

I seem to recall an old code that allowed bathrooms to be vented with an X number of air changes from the HVAC system. Can someone educate me? I know what new code requires.

The oldest code referance i have is 1984. it only allowed for operable window or exhaust fan

[John Cahill]

Thanks all. I may be dealing with a local exception from the long distant past. Some homes in Dallas have a 1/2 bathroom in a hall (toilet sink only). They have no exhaust vent, no recirculating vent, no window, no HVAC return and only a HVAC supply. It is common from the 70's period.

[Bob Elliott]

So to vent the bathroom you push all the humidity into the home?
Something smells here

[John Cahill]

Originally Posted by belliott

So to vent the bathroom you push all the humidity into the home?
Something smells here

That is the difficulty of code. In North Texas the lack of ventilation in a bathroom rarely causes a moisture problem in the home or attic. This would be especially true in a 1/2 bath that is used incidentally. It is proven by performance history on homes that are 40 years old.

I would do it different in your climate.

Odors? A window and fan would do no good for some. It gives the movie title "The Last Airbender" meaning.

Write it up? Sure. Is it material? Not in Texas.

[Bob Elliott]

Originally Posted by jcahill

That is the difficulty of code. In North Texas the lack of ventilation in a bathroom rarely causes a moisture problem in the home or attic. This would be especially true in a 1/2 bath that is used incidentally. It is proven by performance history on homes that are 40 years old.

I would do it different in your climate.

Odors? A window and fan would do no good for some. It gives the movie title "The Last Airbender" meaning.

Write it up? Sure. Is it material? Not in Texas.

I guess if you have no humidity in your climate the bathroom air would be helpful.

[prichardson]

There is not going to be much humidity from a half bath