Hello gentlemen. My thanks in advance for you advice!
I'm installing my own radon system. I know enough to accomplish this safely, and I know code. What I don't know is CFM airflow implications as I exit the house.
I'm going to be running 4" Schd 40 PVC over roughly 10' of horizontal and 10' of vertical (there is a little more, but it gets complicated and isn't a factor here). So fairly short all things considered.
However, I'm going to have to penetrate two engineered floor trusses, and I'll have to use two 90's to get above the bottom of the floor joist and out the holes. I'd much rather do that at 3" PVC, and my general contractor agrees. I'll still reinforce those beams. FWIW, I'm going to see if I can use 4" 90's and then come down to 3" to penetrate the trusses, but that's a space issue and may or may not work out.
My problem: I tend to think a short run of 3" PVC won't hurt much, but I'm thinking ya'll will know better than I. I've seen this calculator, and I suspect I should assign 2 PSI number (it'll be a vacuam, and less then 2" of water column)
And I've seen this:
But I've no idea how to identify the total flow implications. I've been told by one gentlemen that any amount of 3" reduces the entire section to 3" flow. I don't believe that's correct, for the velocity should simply increase through the short 3" section, but I'm well out of my depth here.
Thoughts?
Thanks guys!
D
I'm installing my own radon system. I know enough to accomplish this safely, and I know code. What I don't know is CFM airflow implications as I exit the house.
I'm going to be running 4" Schd 40 PVC over roughly 10' of horizontal and 10' of vertical (there is a little more, but it gets complicated and isn't a factor here). So fairly short all things considered.
However, I'm going to have to penetrate two engineered floor trusses, and I'll have to use two 90's to get above the bottom of the floor joist and out the holes. I'd much rather do that at 3" PVC, and my general contractor agrees. I'll still reinforce those beams. FWIW, I'm going to see if I can use 4" 90's and then come down to 3" to penetrate the trusses, but that's a space issue and may or may not work out.
My problem: I tend to think a short run of 3" PVC won't hurt much, but I'm thinking ya'll will know better than I. I've seen this calculator, and I suspect I should assign 2 PSI number (it'll be a vacuam, and less then 2" of water column)
And I've seen this:
But I've no idea how to identify the total flow implications. I've been told by one gentlemen that any amount of 3" reduces the entire section to 3" flow. I don't believe that's correct, for the velocity should simply increase through the short 3" section, but I'm well out of my depth here.
Thoughts?
Thanks guys!
D