Temperature rise after better ventilation..

Hey fellow growers.

I am having an issue with temperatures that has me confused.

I changed my ventilation setup.

Old setup: 6 inch fan pulling room temperature air through a closed loop with 2*600 watts and exhausting it outside the building through a 3inch duct.

New setup: 6 inch fan pulling much colder air from outside the building through TWO 3inch ducts through the same lights and cooltubes and exhuasting into my apartment.

However, my room is now 3-4C warmer. The cooltubes are much colder to touch now so my question is.
How is this? does this make sense? there should be MORE airflow since an additional duct is being used, and the air is cooler.

The only alternative explaination i can think of is there is alot less canopy in the room now. They are just young clones. Could this be allowing a build up a radiant energy?
Through non absorption of light and lack of perspiration?

I'm very confused.

Thank you for your help.

tT

I as baffled as you.

is the run longer now that you are pullling from outside? might want to up the fan size as the double ducts lower the efficiency. also might want to exhaust outside like the first setup.

The duct run is the same length as before to the first duct hole. The second hole is an extension onto the existing duct lengths.(using a T split)

If the temperature stay high tonight. I may change it back to the old set up just to check that its the pulling of air in system that is causing the problem, and revert back to the pushing air out.

Completely confuzzled...

now thats funny..sorry

I spent the whole night thinking about the issue and came to a possible conclusion.

It looks like the heat has no where to go to so its heating up my apartment. Great but then the intake for the room eventually intakes this air, exhausts it, reintakes it. Eventually just adding heat with no where for it to go. The old system used room temperature air but eventually all heat leaves the building. I shall change the direction of the fan around within the hour and see if that solves this conumdrum.

ok. Flipped the fan around. For the next hour. Think cold thoughts people.

No luck yet.. Still reads 30C. I returned the old system to use. Hopefully it comes back down.... What are the odds that the thermoter may suddenily be out by a few degrees? its a 25$ digital. max n min humidity and temp. the white one that everyone seems to have.

Query: does the position of the fan matter in relation to the ducting? eg: near the end or the start of the ducting?

It shouldn't matter the location of the fan in the system. As long as its pulling air, then its pulling air. Btw I think using 6 inch ducting all the way around would allow better airflow. Don't need 2 3inchers.

Also you said that its no longer a canopy but new clones? So I'm guessing you just harvested and moved the new ones in. If this is the case then yes you may have radiant heat build up, which should go away as the plants fil in. Your getting an inaccurate read on the temp. Either way keep an eye on the root temp! That's more important!

yes, larger plants cool down the room more, more water evaporation and whatnot.

how are local temps also? you aint been having warmer outside temps? (but yeah, going from a huge canopy to a bunch of teenies is gonna raise the heat quite a bit.)

are you sure your not just running at ambient temps............my tent does

@ PeyoteReligion, Thanks for the info regards fan position.
Yes I just harvested and the clones are tiny. about 3-4 inches. I have noticed my humidity is now 37% instead of 55%-60% when my canopy was larger. Perhaps all this is just a cumalitive effect of the radiant heat build up + canopy transpiration.
The soil in the pots still feel cool enough. plenty moist and not warm.
*Cant change the 2*3 inchers as these are pre built into the apartment. Im tapping into an existing venting system.

@ sso, Thanks, I hope it is this issue. As my old system still seems to be 3-4C higher than it was a couple weeks back. The temperatures are warm outside but not different than a few weeks ago. Its been a good summer at 19C approx outside. If it is the case of just less of a canopy. then I would be very happy!

@kush groove, what do you mean? running at ambient temp?


query: is it possible the increasing my fan speed had a negative effect? It has two options. 420 or 800 m3 per hour. The faster air flow couldnt be not giving the air time to capture the heat correct? like faster is better in all cases yes?

@the tinker im currently growing with 400hps and 2 leds and i have enough airflow to keep my tent at whatever room temperature is........so when its 90F outside my growroom is also at 90F
just thinking maybe it got hotter out around the time you made the swap

Highest temps last night were 29C. humidty @ 41%.

Thats a 1C drop and a 4% increase.

Another couple of days and i should know if this will resolve itself or not. Fingers crossed.