Effect of AC unit on humidity?

shiva71

Well-Known Member

• May 30, 2023

• #1

Hiya
Im gonna run my tent through the summer. It can get pretty hot here, 95°F+ isnt unusual so i plan on buying an AC unit and im wondering what effect this has on humidity. Quick google say yes AC units will lower RH which is good.
Can anyone confirm this?
Thanks!!

 

J. Rocket

Well-Known Member

• May 30, 2023

• #2

yes...a/c acts as a dehumidifier.
ever notice the condensate drip line running from every unit?
typically here they are 3/4" pvc pipe.

 

Hook Daddy

Well-Known Member

• May 30, 2023

• #3

Yes, an AC unit will lower RH just like a dehumidifier.

 

shiva71

Well-Known Member

• May 30, 2023

• #4

OK thanks. The dehumidifier I have lowers RH but raises temps so I should replace this with an ac unit to kill two birds one stone.
Cheers!

 

HydroKid239

Well-Known Member

• May 31, 2023

• #5

shiva71 said:

OK thanks. The dehumidifier I have lowers RH but raises temps so I should replace this with an ac unit to kill two birds one stone.
Cheers!

Click to expand...

Correct. I do the same. Just recently acquired a portable ac that has 2 hoses. Will be fun to play with this summer.

 

shiva71

Well-Known Member

• May 31, 2023

• #6

HydroKid239 said:

Correct. I do the same. Just recently acquired a portable ac that has 2 hoses. Will be fun to play with this summer.

Click to expand...

Cheers. But an ac unit has warm air coming out the back which needs ducting to remove it correct?

 

SheeshM

Well-Known Member

• May 31, 2023

• #7

Yes, AC will cool the air and lower RH but in some cases you'll still need the dehumidifier. I had my tent in a hot attic for a few years and had to run a portable AC but still needed the DH. The tent would hit the desired temp, say 80 F, so the AC shuts off. Then, the RH rises when the AC is off which would kick in the DH. The DH would send warm, low RH air into the tent but now the temp goes back up! AC kicks on and the cycle repeats. I used 2 inkbird controllers; 1 for temp and 1 for RH and ended up with good control of temp and RH.

 

driver77

Well-Known Member

• May 31, 2023

• #8

I have a portable AC unit in my grow room also, it has no active drain line and it doesn't lower humidity as much as a window unit seems to. It does have a dehumidify function also and a place to drain water from in that mode. Had to insulate the exhaust because it was so hot.

 

HydroKid239

Well-Known Member

• May 31, 2023

• #9

shiva71 said:

Cheers. But an ac unit has warm air coming out the back which needs ducting to remove it correct?

Click to expand...

Yes, this one I have does. It's not a window unit. It's pretty cool though because it's been told to me that the moisture from the dehu evaporates. I kinda like the idea of that capability.
It has 2 ports in back.

This is the one I have..

CH-PDH14AC3 - COOPER&HUNTER Cooling and Heating Solutions

Cooper&Hunter’s Dual Hose Portable A/C is ideal for temporary or supplementary heating, cooling, and dehumidification. Portables are often utilized during events, when spaces are more crowded than usual, and during construction or repairs of primary A/C systems. 12K and 14K Btu/h models are...

cooperandhunter.us

 

Last edited: May 31, 2023

Jjgrow420

Well-Known Member

• May 31, 2023

• #10

One thing I learned is in humid conditions run the fan on low so the air has longer contact time on the coils and removes more humidity. Effectively cooling the air more efficiently

 

shiva71

Well-Known Member

• Jun 3, 2023

• #11

So lets say my RH was 60%, how good a job does the AC do, does it make a big difference?
Thanks!

 

HydroKid239

Well-Known Member

• Jun 3, 2023

• #12

shiva71 said:

So lets say my RH was 60%, how good a job does the AC do, does it make a big difference?
Thanks!

Click to expand...

My humidity was 64% in my veg tent. I kicked the AC on and it went down to 47-51% within 90mins. (I’m using a window unit)

 

shiva71

Well-Known Member

• Jun 3, 2023

• #13

HydroKid239 said:

My humidity was 64% in my veg tent. I kicked the AC on and it went down to 47-51% within 90mins. (I’m using a window unit)

Click to expand...

Ok thanks thats a significant reduction in RH cheers!