question on ambient temps and growing in a tent in detatched garage

[vindiesel]

I have read that temps in tent usually 10 degrees higher than ambient temp of room tent is in. Im in planning process..lookin to start april 1. This will b first grow at this house. Grows in past were in a cool basement..using a tent and a 250HPS. My only ventilation was passive intakes and 2 4" 112cfm axial fans. Also used a tower fan in tent. Tent never rose above 70-72. Basement always was 68-70.
Now..next and first grow at this house..my only options r attic or detatched garage. If garage gets around 80...ur tellin me automatically the inside of tent will b 10 degrees higher? Again..this is what i keep reading. House is on a very wooded lot..garage is detatched..seperated from house by a breezeway. Its not a hot garage in summer as far as garages go. I was there last summer and remember thinkin i could grow in there. Theres a door on side of garage in breezeway which i can leave cracked open.
I was planning on using a 400HPS instead of 250..but if im already concerned with heat..maybe i should just stick with 250. Setup has to b quiet as can b an kinda stealth. My vaportek 4000 has odor issues covered.
In a perfect world..i would like to use my old tent and ventilation listed above and add an extra 4" axail fan..or even a 6"..so 2 4" 112cfm axials and a 6" axail..with passive intakes with a 400HPS..but maybe i should just stick to a 250. I can add a good 6" exhaust fan duct into rafters but dnt know if its necessary or overkill. Kinda hard planning when i dnt kno what exact temp of garage in summer can b. What do u guys think? I live in NY area. Grow will b april till nov. Thx guys

 

[mpd]

If you are talking about a 10 degree gain I don't see the big deal. My cabinet runs a 20 degree bump over ambient so the temperature is always 95 degrees and the plants grow just fine. I think it all depends on how hot the garage gets. Then again, you are telling me the gain over ambient is only 4 degrees maximum so there really isn't any issue here vin.

 

[Jnugg]

Vin,I had told you with 170cfm exhaust fan that the temps in your tent with a 400w HPS would keep the tents temps (lights on) would be 10°F above ambient...no exhaust fan and easily temps will be 20-30°F above ambient.A 6" 350-440cfm exhaust fan would keep lights on temps (in the tent) roughly 5° above ambient temps.

 

[cravin morehead]

even with just a 400w, if you don't exhaust the heat out of the garage, it will get warmer in the garage. if it gets warmer in the garage, it will get warmer in the tent.
a couple years ago, i ran a 400w cabinet in a spare bedroom. i did not exhaust my heat out of the room. when the bedroom door was open, you could physically feel the heat difference in the room, something like +10*f. with my cabinet exhaust, i could keep temps within 3*f of ambient temps. on warm days, it would get into the upper 90*s inside the cabinet. because of that my buds would be airy and looser. so i thought i'd put a window banger a/c in the room. without exhausting the heat out of the room, that a/c ran very, very often and skyrocketed my electricity bill. after i got smart and ran my ducting out of the room, i had good , tight buds and a reasonable electric bill.
just something to think about...


cm

 

[Smelly_Cheese]

If you are talking about a 10 degree gain I don't see the big deal. My cabinet runs a 20 degree bump over ambient so the temperature is always 95 degrees and the plants grow just fine. I think it all depends on how hot the garage gets. Then again, you are telling me the gain over ambient is only 4 degrees maximum so there really isn't any issue here vin.

wow! 95 degrees. I stress when i get over 80 under the canopy 75 room. But around here your almost asking for mites and bugs at high temps. Summer is super hot so i could imagine no ac. I use ac for veg and flower. Wall and portible.

my suggestion is to run ac into tent

 

[vindiesel]

Yea 95 sounds high. If i need more than axial fans..which i prob will..im gonna duct main exhaust into rafters and drill hole in side of garage. That would blow pretty much into woods. Will b a vaportek in garage for odor.
Thx jnugg.. maybe i shoukd just use the 2 4" axials and tower fan to move air and use a 6" good exhaust duct out of garage. I would have to figure how to make it quiet. Someone said put muffler on exhaust side of fan..not before???

 

[vindiesel]

Yea 95 sounds high. If i need more than axial fans..which i prob will..im gonna duct main exhaust into rafters and drill hole in side of garage. That would blow pretty much into woods. Will b a vaportek in garage for odor.
Thx jnugg.. maybe i shoukd just use the 2 4" axials and tower fan to move air and use a 6" good exhaust duct out of garage. I would have to figure how to make it quiet. Someone said put muffler on exhaust side of fan..not before???

 

[intotheunknown]

Insulated ducting is going to help out considerably with noise.
craven more is right, get rid of the heat. the more heat you add the more heat youre going to be dealing with, so get rid of it.

your garage's ambient temps are going to play a huge role in your tent's temps.
what size tent are you using?
do you even happen to know exactly how hot its going to be getting in your garage?

how exactly is your ventilation system going to run? air cooling the light?
if i were you...

use the 400w and air cool it. pull air from inside the tent through passives at the bottom.
overkill your fan, say one OVER 400 CFM and put that on a speed controller. being able to control that variable right there is going to help you out greatly.

now as far as your ambient garage temps, thats another story. if youre pulling through passives, the incoming air (no matter what) is going to be right around the same temp. and your tower fan is going to be the one somewhat cooling that air down.

thats about all i can tell you other than you possibly will have to control either the garages ambient temps or add an air conditioner to your tent.

in my experience with tents and temperature control, your 2 biggest factors are controlling the light's temps, and the ambient temps. sometimes its one or the other. sometimes its both.

 

[mpd]

Vin, check the muffler construction thread in my signature. Makes fan noise output go lower than the sound your refrigerator makes.