Cfm's needed for 30ft of 4" ducting?

With summer temps in the 90s im going to have to vent my portable ac out of my house via a dryer vent. Im currently venting out of a wall in my room into the rest of my basement.my room temps are 77ish and the bloom tent with the ac facing right into the passive intake is 80-85. Today I went and bought the 4" ducting and adapters needed to hook it up to the ac's exhaust... Only to be dissapointed the room temp spiked to 86 tent to 90. Clearly the run of ducting is too long for the units fan.

So my question is should I get a 80cfm 4" duct booster fan or a 180cfm 6" duct booster fan? Its 4" ducting about 20ft of its straight run on the floor and 6ft up to a window vent.

Setup is 4x4x7 tent with 600w cooltube, 200cfm fan/filter also cooling the hood, 2 6" clip ons in tent, passive intake with 8k btu ac pointing right at it, 4 plants in soil.

I should add the room the tent is in is 90 square ft/585 cubic feet

In a situation like that, the bigger the better. Also, if i'm understanding what you are saying correctly you are putting a y in your dryer vent? If you don't have enough force from your fan, what is ultimately going to occur is the heat just running into your grow room from your dryer.

Thats exactly what happened lol. I didnt think about it at home depot yesterday but I have to go buy a backdraft damper for the piece of ducting connecting to my dryer. Ill get the 6" fan its like $3 more then the 4" I wasnt sure if it was possable to have too much pull on the exhaust of the ac. Thanks for the input!

I miss read you a lil. The heat from my grow was going into my dryer. But makes sense that dryer heat could go into the grow. Do you think a 180cfm would be enough to keep the dryer heat out of the grow?

I dont know if it makes a dif but from the y in ducting to outside is about 6ft. From dryer to y is about a foot. And from ac to y is about 20ft.

LOL. Keep grow ducts away/using from any home or appliance ducting, that's just common sense 101.

At 5am I was tired enough not to have common sense lol. Thanks for the chart fab

it shouldnt be split with your dryer. it needs to have its own ventilation system