Manual D - Rules of Duct Design

[@David_Stumpf]

@HVACProBlog great video, thanks for putting this information out there for all of us to better understand designing these systems!

[@-JonnyBoy-]

I've never done so much research to do my first DIY heat pump install with all duct work... with multi zones... I really jumped in the deep end with this one lol. Some good info here. I'm going to stick with the 2ft rule on mine for branches since i have plenty of space.

[@aldoogie824]

Been pissin in the wind all day with this remodel.

[@HVACProBlog]

This is an extract of the paid online course - Residential System Design, which you can access here: www.patreon.com/HVACProBlog?fan_landing=true For a free Rules of Duct Design PDF Download: mailchi.mp/f11bc3b70d67/63gy9nnhyb Chris Morin is the Author, Owner & Founder of the popular HVAC Pro Blog. For Advice with Residential HVAC System Design, Quality Installation, and System Diagnosis, you can find Chris’ Articles on HVACProBlog.com.

[@lloydminick3016]

Is there a software you would recommend for duct design, for a home designer or architect who is not an HVAC professional, along the lines of simplicity and user-friendliness that Cool Calc offers for load calculations?

[@tttota5421]

I am interested to know more about duck sizing, plenums, unit sizing etc ,do you have videos on that or books that you sell I got manual And J but there is a lot to read

[@HVACProBlog]

Hi TT! Yes, I do offer some exclusive online System Design Training! This video explains: www.hvacproblog.com/patron

[@gypsypath1]

So a contractor doing a 180 around a strap with the flex duct is bad, correct? My contractor has done that, left sags everywhere going around pipes and joists, and refused to connect several main floor, living space ducts to the HVAC system so they can use those to “condition” the basement instead of adding an additional vent to the main trunk.

[@manueljimenez5378]

Thank you sir 🤙

[@briansnurkowski4870]

This maybe an irrelevant question to the topic but i ran into this yesterday we installed a propane furnace with a heat pump duel fuel option horizontally but the system doesn’t qualify for rebates when it lays horizontal, does anyone know what the difference is between vertical and horizontal applications?

[@HVACProBlog]

Most likely it is the tested combination with the a-coil used in that orientation. Did you need to specify a different coil?

[@ryan736]

DIY question with no experience: I have a 2 story home and three rooms with no return duct in them. The return is in the hallway. I was going to put in some jumpers into the attic and I wanted to know if I can run those jumpers through the attic and directly down into the return, or do I need to place jumpers venting into the hallway that has the return in it?

[@camronconlee944]

Not sure if you got an answer to your question; however, I’ll give you a couple ideas. Normally with central return the doors are undercut to allow a return path when the door is closed. Alternatively you could put grilles on either side of the wall above the door with an opening or you could do either of the options you mentioned below. Only drawback to running the return duct back to the return plenum would be allowing for filtration. With a central return you likely have a filter grille which houses a filter to protect your equipment and filter air. If your filter is at the equipment then you need not worry about that.

[@ryan736]

@@camronconlee944 I appreciate the answer! My filter is at the furnace so i shouldn’t have any problems. Thank you for the recommendations!