Reddit mentions of Can Fan Max Fan Mixed Flow Inline Fan, 8-Inch 675 Cubic Feet Per Minute

The purpose of those lines is to create airflow to prevent carbon monoxide poisoning. They function passively, so you should uncap them, for safety sake (or at least make sure a COO monitor is installed... fuck, I don't have one installed....). Notice how one inlet is (or was, or should be) at eye level, and the other is near the floor? That is to make use of when heat rises, the air near the inlet of one will rise out, and the cold air near the bottom of the other will sink, starting a circulating flow. Yes, this chills the basement, but, if it's unfinished that's OK.


a 100k but furnace may use rpoportionatly more air for combustion, but its in a controled space and a very efficient combustion, while the 54K burner will disperse the COO along the heat current it creates meaning you need to remove much much more air to gather all the gasses you should, than with just a sealed vented furnace. Also, there is a difference between inline duct booster fans, which aid in airflow, but lack dynamic pressure, and turbine fans which are both consistant rate and high dynaic pressure (meaning it would be able to pull air from a further distance with less drop in CFM)

These http://www.amazon.com/LEDwholesalers-GYO2402-6-Inch-Hydroponic-Booster/dp/B003YFADW8 won't work,

you'll need this http://www.amazon.com/Active-Air-720-Inline-8-Inch/dp/B002JQ4K1I

or for a quieter operation with better dynamic pressure, this http://www.amazon.com/gp/product/B001I4DHJI/ref=pd_lpo_sbs_dp_ss_2?pf_rd_p=1944687782&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B004C2IWIE&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1V2RCEEAMG31CYMSKC7B

I am not trying to be alarmist, but I know the math off the top of my head, because I've worked with it SOOOoo many times, and as they are for safety, I urge you to heed my warning.

You need 400cfm per light if going air cooled, or around 4000btu per light of AC. Runnng an AC will increase your power bill about 35% over what the lights draw. SO 2000W + an 8000btu AC will be around 2700W total draw. Keep in mind if you do a sealed room with AC, you will also need CO2 supplementation since the plants will quickly deplete it from the air in the room.

Kind of depends in your climate. You can easily run the lights at night so that you have a lower outside air temperature to rely on. So look at your average night temps. If they are 65 or below during the warmer parts of the year, you can probably get away with just using a 900cfm exhaust fan + carbon filter and a 600-700cfm intake fan. If your night temps are much higher than that, you will need AC.

With a small setup like this though, and AC may not be that much more expensive than a fan-cooled setup. This is because smaller fans tend to be less efficient and more expensive per CFM at this scale. So a 900cfm exhaust fan like the can max 8" HO will run you about $225 and draws about 275 watts.

The can max 8" regular fan for an intake (667cfm) runs about $200 and draws 176 watts.

So that's $425 without tax or shipping, and a combined current draw of 450Watts. That's only 250w below what an 8000btu AC draws, which is only around a $15-$20 per month difference in the power bill between the two setups. Not to mention, an 8kbtu AC can be had for less than $200. Not too bad for guaranteed temperature control and lower noise. The larger cost in this case is the additional cost of CO2 supplementation equipment. You need a CO2 controller/regulator which are a few hundred bucks, plus a reliable source to swap out CO2 bottles.