Anyone using duct reducers???

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?

I've done it with 8" fans.
No issues pulling through 3x 6" air cooled hoods.

Are all 4 lights on the same duct in a row? If so split it between 2 branches. You will get more total airflow and better heat transfer.

Easy deal. Just go to your local Heat and Air/Plumbing store and you can get reducers from 16" to 6" and anywhere in-between, or in reverse. Just buy some AC tape to connect them together.

AC Infinity has a Y fitting, I think its two 6" into 8".

psychadelibud said:

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?

Click to expand...

CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)

rkymtnman said:

CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)

Duct Size (Inches)	Flex Duct Airflow (CFM)
5 inches	50 CFM
6 inches	75 CFM
7 inches	110 CFM
8 inches	160 CFM
9 inches	225 CFM
10 inches	300 CFM
12 inches	480 CFM
14 inches	700 CFM
16 inches	1,000 CFM
18 inches	1,300 CFM
20 inches	1,700 CFM

Click to expand...

Minus bends of course

Herb & Suds said:

Minus bends of course

Click to expand...

good point. i mainly posted it cause it amazed me how much a 2" difference makes in flow rates. kinda like different sizes of pvc too. and then like you said throw in a 90 or 2 and a reducer and your flow rate is sharply reduced

MikeMuffler said:

Are all 4 lights on the same duct in a row? If so split it between 2 branches. You will get more total airflow and better heat transfer.

Click to expand...

This is the way

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

Wow, suddenly all of the LED boys are HID Ducting exerts
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

OneHitDone said:

Wow, suddenly all of the LED boys are HID Ducting exerts

Click to expand...

you kinda had to become familiar with ducts when you bring street lights inside where they don't belong.

rkymtnman said:

you kinda had to become familiar with ducts when you bring street lights inside where they don't belong.

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True

OneHitDone said:

Wow, suddenly all of the LED boys are HID Ducting exerts
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

Click to expand...

Wow a lot of the LED guys started with lighting other than LED.

OneHitDone said:

True

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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.

OneHitDone said:

Wow, suddenly all of the LED boys are HID Ducting exerts
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

Click to expand...

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.

OneHitDone said:

Wow, suddenly all of the LED boys are HID Ducting exerts
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

Click to expand...

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.