Building Science Insights: To Vent or Not to Vent

I'm not in the industry but do take home energy efficiency pretty serious. Did exactly what Dr lstibuerk explains on my own home in FL, air sealed the ceiling to the best of my ability(probably not perfect but certainly way better than it was which was a leaking mess), put r60 blown in insulation in attic, added ridge vent when my roof was redone and added more soffit vents, even with my HVAC blower in a hot garage(also air sealed it as well as insulated) and ducting in the attic I saw a 20-25% reduction in energy usage and a much more comfortable home in the hot 90-100 degree days here in fl. It blows me away how much we talk about green energy and spending tens of thousand on solar or other super fancy expensive options yet do nothing in most cases for fairly cheap and very good ROI options. Making our homes more efficient should be the first step in helping reduce emissions/ being greener, instead we put up solar everywhere, windmills, buy hybrid/electric cars, set mandates of emissions on everything yet our homes are bleeding fossil fuel every minute of the day 365 days a year, imagine the impact if every home saved 20-25% on energy usage.

As a builder I have said for many years now that INSULATION without VENTILATION will equal CONDENSATION

Joe, that was a great presentation! Thank you so very much for sharing all you hard won knowledge. I totally agree the failure teaches way more than success and that being an engineer with practical field experience the ability to learn from your mistakes is what makes the difference. Also, contrary to some comments, when I set out watching your video I did it with the attitude of "I didn't come a knowin i came a learnin". That bit of wisdom I was given by you guessed it an Old Timer over 20 years ago. Again thanks!

There is only over-designing or under-designing. A good over-design will cost 10% more than needed. A bad over-design will cost 50% more than needed. Any under-design will cost >300% more then needed.

He has the tech knowledge... I hope I got the basics right. My attic is drafty, I can hear people on the street, it kinda amplifies the sound, and now I feel good about that...

Well put, if you've worked in the industry for any practical amount of time, this should make sense, at least in a summed up simplified overview. As he says, we complicate the issue with a lot of "ideas" but the facts and science behind is the way it works, regardless. Thanks for the video, very refreshing to see after 20 years of arguing with "contractors".

Fabulous presenter. Thanks to Owens Corning for sponsoring this sort of thing and making it available to the general public.

Had the pleasure of attending your presentation when you came to Vancouver. Brilliant

Great talk and presentation ! made me laugh while happily keeping my full attention to the technical content, well done :)

love Joe's books..straight forward Building Science !

High SEER ductless mini splits have worked very well for us.

Fantastic presentation!

Love the ridge gap vapor diffusion idea!

I would agree with moving the Air Handler and ductwork out of the Attic now you just have to convince the builders and Architects who keep designing structures with the mechanics in the attic because they don't want to give up the storage or closet space

Excellent presentation! I learned a lot!

Thanks for all the info. Does this same concept apply to standing seam metal roof? (southern Indiana)

The people who understood what that man was saying, already knew everything about it!

"In my heart, I know I'm funny"

thank you for this presentation

The only ductwork I have in my attic is coming from the fan on my stove and microwave a second and third would be the venting for my two bathrooms going up through the roof. Are those okay to have in the roof if not where do you vent them to? And all my other venting including my washer dryer goes out through my basement including the heating. No air conditioning in my house except for window air conditioning. And I realize that these three events do take some of the heat out of my house but they also take away the smell in the bathroom and the humidity from the bathrooms and the smells from cooking. I also have several 6in charcoal filters at using my grow rooms should I rather have a 6in charcoal filter just of Andre circulate the air inside my house as well? Thanks for any information you can give me.