4x4 Tent Air Conditioning problem, could use some advice please?

[KarlJay]

I have to say that I'm really surprised you have 115 temps with outside high temps of 85 using 1 1000W HPS.

I'm running 4 600W HPS lights and the only time I have heat issues is during a heatwave where the outside temps are over 110 and I was able to control temps with a 5K BTU window A/C

You have 14K A/C and a 1000W HPS. That should be more than enough to keep the heat out.

I also see that you're running lights on at night, so I'm really confused as to why you have any heat issues at all. I run my lights during the day and it's been over 110 and I'm running less A/C and over twice the light wattage.

I'm suggesting that something is setup wrong. From the sounds of it, you have all the right equipment.

You have a tent in a garage with no insulation.
High temps about 85, low about 50.
1 14K portable A/C
1 1000W HPS
1 exhaust fan.

Right?

Ok, how are you getting the hot air out? You should have 2 exits: 1 A/C exhaust, 1 regular exhaust fan from the tent.

How are you getting the cold air into the tent?
How are you getting the hot air out of the tent?
How are you getting the hot air out of the garage?
How is the attic vented? Are you venting directly to the outside or is it a passive vent in the attic (does the attic have a fan).

From what you've said:
Your inside temps are more than your outside temps. Sounds like the portable A/C is not venting to the outside, did make a vent to directly vent the A/C outside or does it just go up to the attic?

It might help if you provide some pics of your HVAC system, the A/C, fans, vent, tubes, etc... Or at least a drawing of how it's setup.


I can't offer any help on mites except that I've heard they don't survive well in low humidity. I've been told that humidity below 30 or even below 20 is fine. I used ladybugs in my last grow, you can buy them live at local plant shops, but I don't know if ladybugs eat spider mites, they probably do, but ask around, they don't hurt the plants and are great for many pests.

Post up some pics and/or drawings of your whole system.

 

[Jimmycricket]

I can't offer any help on mites except that I've heard they don't survive well in low humidity. I've been told that humidity below 30 or even below 20 is fine. I used ladybugs in my last grow, you can buy them live at local plant shops, but I don't know if ladybugs eat spider mites, they probably do, but ask around, they don't hurt the plants and are great for many pests.

Whoever told you that must have hit their head.

Spider mites thrive in dry atmospheres. The lower the humidity and the higher the temps the more mites like it. In other worlds a 10% humidity with 120 degree temps is a near perfect spider mite breeding ground.

As for ladybugs, yes they eat spider mites. They much prefer aphids but if you put them in a tent that has spider mites they will surely eat them.

 

[TheGreatHerb]

Hey there sorry about the confusion but to clear things up yes the ac unit is more then enough to handle all heat issues

first off let me restate my problem my unit cools the room to 70 degrees then kicks off during this time the heat rises fairly quickly and in the heat of the day it will hit 85 before the unit kicks back on with that being said

I have to say that I'm really surprised you have 115 temps with outside high temps of 85 using 1 1000W HPS.

The tent is 85 at the highest and my outside temps are 115 at most

during the day when the lights are off it is 100+ in the garage around the tent and the time between when the ac kicks on and off is too far apart its not a big heat issue i am really having but a cold issue during the night because the ac must be left on all night and at about 4 in the morning say its 60 outside my tent gets 55 im not there at night to adjust the ac so i was thinking maybe putting the fan on the aircooled hood on a dimmer so it keeps it warmer at night?

As for your questions

How are you getting the cold air into the tent? I have a portable ac in the tent generating the cold air.
How are you getting the hot air out of the tent?
As for the heat the 1000w generates I have a aircooled hood taking air in from outside and expelling it outside.

as for the heat the ac generates it is exhausted outside as well
How are you getting the hot air out of the garage?
i have no way to get heat out of the garage it is always hot even at night
How is the attic vented? Are you venting directly to the outside or is it a passive vent in the attic (does the attic have a fan).
no there is no fan just a small vents a few of which i am using to exchange air and heat for the tent


The ac is vented directly outside

I will post pictures of my whole setup tonight

 

[Jimmycricket]

Ok herb here is your answer (unless i am not understanding something).

Turn your A/C to 70-75, this will mean it of course wants to always be at that temperature. Once it is at that temp or slightly lower the a/c turns off and it just blows air until the temps get 5-10 degrees warmer then the thermostat is listed for. So once the temps hit around 80 degrees maybe 85 it will turn the condenser back on and start blowing cold air.

If the temp ever gos below 70 the cold air stops and itll just act like a fan and circulate air.

It sounds like right now you just have the A/c set to "On" so its always working. Its better to use the set temperature setting and as I said before I would suggest 70-75 as my set temp.

 

[TheGreatHerb]

Ok herb here is your answer (unless i am not understanding something).

Turn your A/C to 70-75, this will mean it of course wants to always be at that temperature. Once it is at that temp or slightly lower the a/c turns off and it just blows air until the temps get 5-10 degrees warmer then the thermostat is listed for. So once the temps hit around 80 degrees maybe 85 it will turn the condenser back on and start blowing cold air.

If the temp ever gos below 70 the cold air stops and itll just act like a fan and circulate air.

It sounds like right now you just have the A/c set to "On" so its always working. Its better to use the set temperature setting and as I said before I would suggest 70-75 as my set temp.

yep that sounds right i had it too low so im going to set it to 72 is there any to maybe cut that time to 5 degrees or is it just impossible

thanks alot man you've helped alot even though i may have confused ya a bit sorry

 

[Jimmycricket]

Well exactly what temperature it turns back on is almost always just built into the unit and is not adjustable. It is typically between 5-10 degrees above your set temp.

I suggest setting it for 75 degrees since 85 is a perfectly ok temp for weed. this will keep your range between 70-85

Also another easy way to get rid of the spider mites is using diotomacious earth or sulfur.

 

[KarlJay]

To me it sound like you have all the right equipment and sounds like a very workable system.

Passive attic vents suck, they don't move much air. A fan will compress the air and get it out. Home Depot and others sell a temp controlled fan for cheap.

I got 2 3-Speed High Velocity fans from WalMart (I think these are them, the price was < $20)

Comfort Zone CZHV9B 9-Inch 3-Speed High Velocity Cradle Fan: Heating, Cooling, & Air Quality : Walmart.com

They REALLY move some air !!! they are NOT like a box fan or personal fan, they MOVE AIR!!!

If your attic has zones (sections), you can move the air to another section and get it to another vent.

You can add a soffit vent without too much work and it does NOT require cutting the roof. you can put a fan that pushes the air out the soffit vent.

These are generally cheap solutions, you can add a $10 timer and have attic fans come on only at certain times.

I put a 2ton A/C in my attic, I got a 220Volt timer that turn it on full blast 1 hr before lights on and 2 hrs after lights off. I'm a BIG fan of timers, last thing you want is to forget and kill/damage the crop.


All these suggestions should be done AFTER you follow what Jimmy said. Also, they might cut the elec bill a bit by removing some load from the A/C to a simple attic fan.

One last note, the colder temps. Ridged foam boards are pretty cheap, you can run these along the walls and make a nice box for the tent for pretty cheap and they really help keep temps stable. I set this up for a shed grow in the winter and it really helps.