Anyone using duct reducers???

psychadelibud

Well-Known Member
So the last few summers I have been having some heat issues even with my minisplit full blast. Spring, fall and winter grows hardly ever have issues.

I have 4 1000 watt HPS in air-cooled hoods designed for 6 inch duct. Been running a 6 inch inline fan to pull air through the lights. My plan is to upgrade to an 8, 10 or maybe even try a 12 inch inline fan with a 6 inch reducer. My duct is very long in general, thats just the way my room is laid out/designed unfortunately and funds are an issue right now to be updating hoods/ducting/etc.

If I could just get more airflow through my hoods/duct the summer heat issues will be terminated. I'm very desperate, so I'm probably gonna go on through with this anyway and if anything it will be a little experiment.

Not really wondering if its okay to do as much as I am curious if anyone out there has ran something similar and how did it work out for you?
 

rkymtnman

Well-Known Member
So the last few summers I have been having some heat issues even with my minisplit full blast. Spring, fall and winter grows hardly ever have issues.

I have 4 1000 watt HPS in air-cooled hoods designed for 6 inch duct. Been running a 6 inch inline fan to pull air through the lights. My plan is to upgrade to an 8, 10 or maybe even try a 12 inch inline fan with a 6 inch reducer. My duct is very long in general, thats just the way my room is laid out/designed unfortunately and funds are an issue right now to be updating hoods/ducting/etc.

If I could just get more airflow through my hoods/duct the summer heat issues will be terminated. I'm very desperate, so I'm probably gonna go on through with this anyway and if anything it will be a little experiment.

Not really wondering if its okay to do as much as I am curious if anyone out there has ran something similar and how did it work out for you?
CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)
Duct Size (Inches)Flex Duct Airflow (CFM)
5 inches50 CFM
6 inches75 CFM
7 inches110 CFM
8 inches160 CFM
9 inches225 CFM
10 inches300 CFM
12 inches480 CFM
14 inches700 CFM
16 inches1,000 CFM
18 inches1,300 CFM
20 inches1,700 CFM
 

Herb & Suds

Well-Known Member
CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)
Duct Size (Inches)Flex Duct Airflow (CFM)
5 inches50 CFM
6 inches75 CFM
7 inches110 CFM
8 inches160 CFM
9 inches225 CFM
10 inches300 CFM
12 inches480 CFM
14 inches700 CFM
16 inches1,000 CFM
18 inches1,300 CFM
20 inches1,700 CFM
Minus bends of course
 

hotrodharley

Well-Known Member
Flow velocity is increased when going through a smaller lumen. It’s called Venturi effect. This is due to decreased pressure along duct walls.
 

OneHitDone

Well-Known Member
Wow, suddenly all of the LED boys are HID Ducting exerts :lol::lol::lol:
But yes, split the run. On 6" 2 in line is probably the max with 1000's. That was the whole sales pitch with 8" hoods is you could run more in a row.
I always prefer to push through the hoods rather than pull. If your in a spot where odor is an issue it prevents smells from being sucked in through any leaks in the venting system and also keeps your fan from running hot due to heated air.
What I have done that worked very well is an 8" fan with a 8" x (2) 6" Duct Y to spilt the run.
You can also use insulated duct between the hoods and on the outgoing side for another small gain :peace:
 

hotrodharley

Well-Known Member
Wow, suddenly all of the LED boys are HID Ducting exerts :lol::lol::lol:
But yes, split the run. On 6" 2 in line is probably the max with 1000's. That was the whole sales pitch with 8" hoods is you could run more in a row.
I always prefer to push through the hoods rather than pull. If your in a spot where odor is an issue it prevents smells from being sucked in through any leaks in the venting system and also keeps your fan from running hot due to heated air.
What I have done that worked very well is an 8" fan with a 8" x (2) 6" Duct Y to spilt the run.
You can also use insulated duct between the hoods and on the outgoing side for another small gain :peace:
Wow a lot of the LED guys started with lighting other than LED.
 

rkymtnman

Well-Known Member
Cities that are making the changeover to LED lighting are reaping the benefits. Los Angeles, for example, installed 150,000 LED streetlights with an anticipated goal of saving $8 million a year in lighting costs, while New York City hopes to recoup $14 million a year through its conversion of 250,000 streetlights to LEDs.
 

ChrispyCritter

Well-Known Member
Wow, suddenly all of the LED boys are HID Ducting exerts :lol::lol::lol:
But yes, split the run. On 6" 2 in line is probably the max with 1000's. That was the whole sales pitch with 8" hoods is you could run more in a row.
I always prefer to push through the hoods rather than pull. If your in a spot where odor is an issue it prevents smells from being sucked in through any leaks in the venting system and also keeps your fan from running hot due to heated air.
What I have done that worked very well is an 8" fan with a 8" x (2) 6" Duct Y to spilt the run.
You can also use insulated duct between the hoods and on the outgoing side for another small gain :peace:
Pulling air through ducts pulls it to the fan and through it. Pushing it allows it to go wherever there it no resistance or wherever there is a leak in your duct (why do you have gaps or leaks anyway if you're such a pro?). Stop giving bad advice. You're a constant tool on here. Why do You even participate if you're not trying to help anyone? Grow up.
 

MikeMuffler

Active Member
Wow, suddenly all of the LED boys are HID Ducting exerts :lol::lol::lol:
But yes, split the run. On 6" 2 in line is probably the max with 1000's. That was the whole sales pitch with 8" hoods is you could run more in a row.
I always prefer to push through the hoods rather than pull. If your in a spot where odor is an issue it prevents smells from being sucked in through any leaks in the venting system and also keeps your fan from running hot due to heated air.
What I have done that worked very well is an 8" fan with a 8" x (2) 6" Duct Y to spilt the run.
You can also use insulated duct between the hoods and on the outgoing side for another small gain :peace:
To me this is bang on advice. Exactly how I would do it. Try to keep the 6" duct runs similar length and shape for it to self-balance.
 
Top