Ventilation questions

i drew a diagram to help show you guys what my ventilation sytem idea looks like but ive been trying to upload it for about an hour and it wont work so im goin to explain it with words.

The box is 60''H x 26''D x 30"w
the closet is twice the size
in the closet door about 12 inches from the bottom is a hole with a dryer vent cover as a passive intake
in the bottom of the box is a hole with a cover like the door for a passive intake into the box
on top of box is a hole attached to the vent for intake into my reflector (passive)
on top right corner of box is a carbon scrubber attached to a inline fan going out of the box
on top of the box is another fan exhausting air from the reflector
both exhaust line run into a T-connector wich is then hooked to the top of my closet to exhaust the air into the top of the room
both exhaust fans are inline 80 cfm
High Tech Garden Supply
this was my design for a good ventilation system any advice pointers and suggestions would be appreciated im installing the ventilation system next weekend let me know what ya think and ill try and get the file to attach

i think i got it

I dont know a lot about ventilation but from what i've seen yours looks good. I have had a lot of problems with the site the last few days. Cant answer post, Server too busy, or i just cant get on the page at all. Then when i can answer post it takes like 5 min to load. I dont know whats up with it.

Be sure you 'T' that into a bigger pipe to exhaust it. 6" line has more then twice the capacity of a 4" line. 8" is almost twice the size of a 6" etc. VV

so should i get a T that transfers into a 6 or a 8 inch

That 'T" is going to give you problems. You need a 'Y' splitter that will split into a larger diameter single... Also i think those are fan boosters, they don't move much air and probably won't be sufficient.

im sorry i meant to tell you guys the one for the reflector is a 6in 250cfm fan cause the reflector has 6 inch flanges and a y conector got it but this is the description of the fan

Rated at 250 cfm (cubic feet per minute)
Tried and true tools for the heating and cooling trade, wisely adapted for cooling grow light reflectors. An Inline Duct Fan is a reliable and cost effective way to keep temperature in the indoor garden under control. Use one fan per light or to increase the efficiency of an exhaust system. These economically priced fans have a lesser cfm (cubic feet per minute air exchange) than the high output CAN-FANS also available on this site. Perfect for air cooling a single lighting reflector or ventilating a small closet sized grow room.
Wired to plug into a standard household outlet!

6" Inline Fan

wich it is going to be used for a single reflector and another on is going to be used for a small closet

so will these be sufficient or am i going to have to send these back when they get here and look at something else

I use the 8" for a room that is about 10x20x10. I'm sure the 6" vented to the outdoors will the job. Major is right, your connection should be a 'Y' not a 'T'. With a t you have fan pushing against fan, not real efficient. If you are going to connect both lines together at some point, go with the 8" duct after that. VV

So i went to home depot today and tried to find a Y connection that would fit a 4" and 6" into an 8" and they didnt have any but they do have the supplies to make this and i was wondering if that might work

i guess not o well ill go fire one up and come up with another idea

q_tip201 said:

i guess not o well ill go fire one up and come up with another idea

Click to expand...

Your room is EXACTLY like mine its scarey. Tell us about the light you are using ?

those reducers are going to cause you a problem. they create too much backpressure for the fan to work properly. i have a 6 inch fan and was using 4 inch to 6 inch reducers and i was moving absolutely no air because of it.

i have decided on a 400 hps/mh combo with air cooled hood
i might get a 600w if i can pull it off but i think ill start with a 400

those reducers are going to cause you a problem. they create too much backpressure for the fan to work properly. i have a 6 inch fan and was using 4 inch to 6 inch reducers and i was moving absolutely no air because of it

for the record jhonny im not reducing the the space for air to pass my room exaust is going to be 4in and my reflector exhaust is going to be 6in the reducer are being used opposite to increase the air space for it to flow it is going to be exhausted from the 8 in hole and the 4 and 6in reducers are theyre to make the passage bigger so theyr is enough space to suit a combination of a 4in tube with a 6 in tube pushing to the bigger hole not reducing expanding

idk mabye im just high but im an exelent mathmatician and the way i figure if a 8 inch can roughly hold the same amount of air as 2x 6 in using a 6in+4in into an 8 inch i should only be using about 75% capacity and theyre should therefore be a lack of presure

I am not going to pretend like I know anything about growing put but I will try my best to help here. I am making all this up as I go so take what I have to say lightly.

Odor;
Is your room 100% airtight ? If the answer is anything less than 100% you are still going to have issues with odor. Only the exhaust in your diagram is going to be scrubed of odor. This means that any air that escapes the room will SMELL it also means that each time you open the door to enter the area its going to SMELL up your house. IMO the carbon filter does two things, first it scrubs the air very well I might add but second it has it own smell to HELP mask/cover existing orders.

My two solutions;

1) At the end of the exhaust cicuit on the outside of the door consider installing something that will blow the air down a little. IMO you should try to get 10%-15% of the exhaust air to flow back into the room. By doing this you will not only improve cicurlation but you will be putting that carbon air back in the room to help mask the smell.

2) Remove the carbon filter from the exhaust cirucit. Run the filter with a 6" inline independent of anything else. Preferably on the same side of the room as your exhaust. You could easily suspend the two from the ceiling.

From the diagram it looks like you have a box inside of a closet I am going to assume that is not the case. As others have stated the "T" duct is not going to work if you followed the diagram. However a "T" duct will work just fine if the fan is between the "T" duct and the door.

A 4" anything is not going to work especially the inlines you find at HomeDepot. These types of inlines at HD and anywhere for that matter are worthless. IMO their CFM ratings are based on the most optiminal conditions. To acheive the optiminal conditions you are going to need other fans anyway. I dont know how to explain other than saying these types of inline fans do not have the power to generate air without something else helping them. On more than two occassions working with them my finger or hand brought the cheap plastic blade to stop with little to no pain.

I would suggest using an 8"-12" intake at the bottom of the door. In front of this intake inside of the closet placea box fan to blow the air in. With the larger intake and additional air you MAY be able to make the two 6" inlines in the diagram work with a "Y" duct piece. Also consider in my example above placing the ballast between the intake and the box fan, this will be the coolest area of the room. Placing the ballast anywhere else in the room will add to your temps IMO.

I know that is alot to take in, do not hesitate to drop me a PM if you have any questions. GOOD LUCK.

Ohh and here is what my mess looks like. Even in my setup the 8" inline from HD is worthless without the box fan pulling and the 15% off the Can-Fan pushing.


I would also us the search button and run snoop dogs name above through system. He has an excellent post on room temps and understanding the difference between actual temps and radiant temps. I am now running my light about 2 inches from the plants.