Grow Room A/C

[CannabisJohn]

First of all thank you all for your input, I have been getting allot of new info in this forum. I'm getting all my materials this week to start building my grow room which actualy is a complete bedroom, all my materials are being shipped from the US and I will be getting them by Thursday, I live in Aruba and it is summer the whole year round, so I bought a 18000 BTU inverter, that will have to cool a 14 feet by 13 feet room with 5 600 watt HPS (Gavita) light(1140 cfm Vortex exhaust fan). But I am wondering for a couple of days already about 1 issue that I haven't heard anybody talking or posting about and that is: I want my hps lights to go on from 7:00 pm till 7:00 am when I'm going into flower. For the vedge I have 3 4x8 T5 each 400 watt+ so vedging would not give me heat problems, but now this is my

QUESTION:
If my lights go off at 7:00 am I know that temp will drop if I turn my AC off at the same time the lights go out, will this affect my plants, what I'm trying to say is that it will be night time for the plants when it is daytime for us, because rightnow in Aruba the temp today is at 91.4F at daytime, room is completely sealed though, I'm thinking that maybe the outside heat can bring temp up in the room after a couple of hours, not that it will be hot in the room, but what I want to say is, that if it is a must for the plants that night time temp must be lower than day time temps?
Will this have an ill effect on them?
Has one of you guys dealth with the same situation? I will have ventilators working when lights are on or off to keep airflow. And I can't change the schedule, what's day time for us must be reversed into night time for the plants.

I hope you guys understand wat I'm trying to say o_O !!

Most growers want an 8-10 degree difference in canopy temps between lights on and lights off. So typically 80-82F with lights on and 72-74F with lights off. This also assumes u are using CO2. Hope that answers your question. Keep in mind that is canopy temps.

 

[Peacegrowers]

Most growers want an 8-10 degree difference in canopy temps between lights on and lights off. So typically 80-82F with lights on and 72-74F with lights off. This also assumes u are using CO2. Hope that answers your question. Keep in mind that is canopy temps.

Thank you for your reply CannabisJohn. So the AC must be on 24/7 in my situation.
Thank God it's an inverter 21 seer.

 

[CannabisJohn]

Thank you for your reply CannabisJohn. So the AC must be on 24/7 in my situation.
Thank God it's an inverter 21 seer.

Thank you for your reply CannabisJohn. So the AC must be on 24/7 in my situation.
Thank God it's an inverter 21 seer.

I would recommend it.

 

[JahStone]

My AC shutdown today during lights off.
During the diagnostic test I get a continuous beep for E7 (DC fan motor fault) and double beeps for E6(faulty compressor startup),E5 OL started
No grease on the lines.
AC guy doesnt know whats up

 

[SoSay]

First of all wanted to thank you in advance for your time and help on this! Been following the thread , but nver signed up till just know to ask this question.. I'm in a critical spot here~~
My LG 18,000 btu unit is brand new and when I plug it in , it turns on, but it never gets going. Therefor not cooling the room.
My room is only 192 sq ft. (16x12x8) with 8 1,ooow vented hoods with a 10'' and 8'' vortex inlines pushing air.
I called LG and they said it wasnt working because the machine 's sensor indicated it was too small of a room. IS that even possible and whats wrong with my unit???!!! Thx

 

[CannabisJohn]

First of all wanted to thank you in advance for your time and help on this! Been following the thread , but nver signed up till just know to ask this question.. I'm in a critical spot here~~
My LG 18,000 btu unit is brand new and when I plug it in , it turns on, but it never gets going. Therefor not cooling the room.
My room is only 192 sq ft. (16x12x8) with 8 1,ooow vented hoods with a 10'' and 8'' vortex inlines pushing air.
I called LG and they said it wasnt working because the machine 's sensor indicated it was too small of a room. IS that even possible and whats wrong with my unit???!!! Thx

What type of unit? Window a/c is what I assume. I have never heard of that before now. Does it start at all? Or does the fan blow but no cold air? What is model number?

 

[Alice D]

I have a couple questions for you if you don't mind? First I've been looking at 5 ton split systems Rheem,goodman,Trane and also Excel air. Excel air systems are nice because of ease of installation but their price tag is double of others. I guess I don't understand on some of these units there are 3 pieces of HVAC equipment condenser,cased coil and the air handler. I've hooked up handfuls of mini splits but what's up with the cased coil? I don't understand exactly what this is for or where in the system it hooks up to. Then on some of the goodman units they offer AC only unit or with a heat strip installed but in the picture they show a coil on top of the air handler. I'm confused about the coil are some installed in the air handlers? Also with these stand up air handlers wouldn't you need a plenum to hook your return to and also have your air ducting come from? If I wanted to hook a system like this into my garage does it matter the size of the return duct compared to my sq footage and also how many btu's of heat I'm trying to take away. Would I need a exact amount of air being pushed back in the room? Like 4-8" ducts or 2-10" ducts? Unfortunately I don't know anyone that does HVAC that I could have come into my grow room and set a system like this up. Am I best just paying the money for excel air system? Sorry for all the questions I hope I didn't confuse you. Thanks

 

[SoSay]

What type of unit? Window a/c is what I assume. I have never heard of that before now. Does it start at all? Or does the fan blow but no cold air? What is model number?

Its an LG window unit model # LW1813ER .
I does turn on and blow room temp air gently out but when it tries to get going and start up, it cuts out... :/
WTF?

 

[CannabisJohn]

Its an LG window unit model # LW1813ER .
I does turn on and blow room temp air gently out but when it tries to get going and start up, it cuts out... :/
WTF?

Need to check voltage of outlet and make sure it is within nameplate specs for unit. If that is good then get it serviced. Sounds like compressor maybe trying to start but can not. That is my best guess. IMO room size has nothing to do with it.

 

[CannabisJohn]

I have a couple questions for you if you don't mind? First I've been looking at 5 ton split systems Rheem,goodman,Trane and also Excel air. Excel air systems are nice because of ease of installation but their price tag is double of others. I guess I don't understand on some of these units there are 3 pieces of HVAC equipment condenser,cased coil and the air handler. I've hooked up handfuls of mini splits but what's up with the cased coil? I don't understand exactly what this is for or where in the system it hooks up to. Then on some of the goodman units they offer AC only unit or with a heat strip installed but in the picture they show a coil on top of the air handler. I'm confused about the coil are some installed in the air handlers? Also with these stand up air handlers wouldn't you need a plenum to hook your return to and also have your air ducting come from? If I wanted to hook a system like this into my garage does it matter the size of the return duct compared to my sq footage and also how many btu's of heat I'm trying to take away. Would I need a exact amount of air being pushed back in the room? Like 4-8" ducts or 2-10" ducts? Unfortunately I don't know anyone that does HVAC that I could have come into my grow room and set a system like this up. Am I best just paying the money for excel air system? Sorry for all the questions I hope I didn't confuse you. Thanks

Coil actually does the cooling. Refrigerant runs thru coil and warm air around coil to cool air. Duct sizing is very important. It depends on length of run and type of ducting. Unless you have a bunch of specialized HVAC tools forget installing a regular split unit. IMO Excel is way,way,way overpriced but maybe your only option. But keep in mind duct size is still important for Excel unit. So if you go that way let me know and I will help with duct sizing.

 

[Alice D]

Coil actually does the cooling. Refrigerant runs thru coil and warm air around coil to cool air. Duct sizing is very important. It depends on length of run and type of ducting. Unless you have a bunch of specialized HVAC tools forget installing a regular split unit. IMO Excel is way,way,way overpriced but maybe your only option. But keep in mind duct size is still important for Excel unit. So if you go that way let me know and I will help with duct sizing.

Thank you for your info i appreciate it much.I just found a stealth excel air system 5 ton used two cycles for 2,500$.I'm going to pick up this coming weekend.Whats your opinion on this fabric duct i've been seeing online?Would this be something i would want to use and what size would i need for a return and how many and what size for the incoming air inputs? I'll give you a little run down of my siyuation. I have 4" insulated foam on every wall and ceiling in my room.It's a sealed room with 12-1,000's and as many 600w verticals i can run until it gets over 84 degrees right now 6-8.I have the big solatel 12 burner Co2 burner.5- dehumidifiers ranging from 100 pint,70 pint and 3 55 pints. Eventually i'll get 2-150 pint Dri-eaze dehumid's.When talking with this guy about the excel air he said i would need a new line set because excel air's line sets connections are only meant for one install.Do you know anything about this?Thanks for help oh ya my room size is 20x18x9.I currently have 2-2 ton wall shakers that alright so i'll have those for back up since summer temps hit 110 degrees a few times a year but i do see snow a few times in the winter about 3000' elevation

 

[Alice D]

Forgot to add All my lights are non aircooled either e-Pappillons or adjust a wings and ballast that can be outside the room are.Thanks again

 

[CannabisJohn]

Thank you for your info i appreciate it much.I just found a stealth excel air system 5 ton used two cycles for 2,500$.I'm going to pick up this coming weekend.Whats your opinion on this fabric duct i've been seeing online?Would this be something i would want to use and what size would i need for a return and how many and what size for the incoming air inputs? I'll give you a little run down of my siyuation. I have 4" insulated foam on every wall and ceiling in my room.It's a sealed room with 12-1,000's and as many 600w verticals i can run until it gets over 84 degrees right now 6-8.I have the big solatel 12 burner Co2 burner.5- dehumidifiers ranging from 100 pint,70 pint and 3 55 pints. Eventually i'll get 2-150 pint Dri-eaze dehumid's.When talking with this guy about the excel air he said i would need a new line set because excel air's line sets connections are only meant for one install.Do you know anything about this?Thanks for help oh ya my room size is 20x18x9.I currently have 2-2 ton wall shakers that alright so i'll have those for back up since summer temps hit 110 degrees a few times a year but i do see snow a few times in the winter about 3000' elevation

I would do 20 inch return duct or if you want 2 separate ducts then do 14 inch. For supply run 1-18 inch duct down center with KD pipe or spiral wound duct ( both are metal ducts). Then install 8 supply air registers down the pipe with 4 on each side. Yes their line sets are only good once for a self install because the line set is sealed and you puntuture it when you connect it. So when disconnected it is open and gets air and moisture in line set.

 

[Pizzapunk]

Hello everyone. Quick question, i have a friend who plans oncooling a 4k bare bulb room with a 36k btu ac. I looked it up and it runs 18 amps so im trying to talk him out of it as it would beinefficient right? Id think he would need a 18-24k btu at most. I know it would run way less but turning on and off for 12 hours would use alot of wasted power? Thanks

 

[CannabisJohn]

Hello everyone. Quick question, i have a friend who plans oncooling a 4k bare bulb room with a 36k btu ac. I looked it up and it runs 18 amps so im trying to talk him out of it as it would beinefficient right? Id think he would need a 18-24k btu at most. I know it would run way less but turning on and off for 12 hours would use alot of wasted power? Thanks

You are right. Also unless the unit is an inverter type mini split the unit will cycle way too much and the compressor will most likely fail too quick. If it is an inverter type mini split and he wants to expand in the near future, then he should get 36k unit.

 

[masshole61]

I have a mini split question. Im building two 4000w flower rooms (open bulbs)and I plan on running alternate 12 hour flower cycles . While one room will require cooling (lights on)the other may require heating (during lights off). Can one mini split system do this? If so what size split would I need? Would it be possible to find a system like this and a high seer?

 

[CannabisJohn]

I have a mini split question. Im building two 4000w flower rooms (open bulbs)and I plan on running alternate 12 hour flower cycles . While one room will require cooling (lights on)the other may require heating (during lights off). Can one mini split system do this? If so what size split would I need? Would it be possible to find a system like this and a high seer?

With my recommendation of 6000 btus per hr for 1 kw of open bulb each room will need 2 tons per room. You can get 4 ton minis but must do minimum of 4 zones and they are super expensive. Do a separate unit for each room. It will be less expensive.

 

[LPwannabe]

Hi John,

If I have a mother room of 24'x40'x10' with 100 mothers, 12 600W MH lamps - what kind of system do I need to adequately remove humidity? I'd like to retain between 65-75% RH and about 70 degrees F.

By the way - Woodsman sent me here.

 

[Twisted pleasure]

Well provided your MH bulbs are OPEN hood.

Simple Math provided by John Your looking at needing 3.6 tons of AC

600 watts x 12 = 7,2oo watts you need 6,000 btu per 1k of lighting OPEN hood.
So each ton is 12,000 btu so you need a 1/2 ton pr 1k is 6,000 x 7.2k with a total of 43,200 total btu needed.

I would buy 2x 24,000btu units for this and have a bit of over kill with 48k btu
and it would be less expensive that route. The RH will be some monitoring in a perfect
world an ac can help with RH they try to work this down to about 50% but you will have to monitor this
and use a DH with a controller. But with that much space and constant watering and With that much space you will need to be well insulated to ensure your not working against any outside elements. Even in doors from my experience the larger the space the more you need to insulate. Your talking 9,600sqft even a 2 degree fluctuation in either direction will be a strain on your heating and cooling. And insulation really makes a huge deal.

Hope this helps. Thats my 2 cents. John take it away.
Hope u dnt mind me popping in with a hand John...

 

[LPwannabe]

Thanks for replying Twisted, much appreciated!

I'm new to this, so I assume by 'open' you mean the bulbs are not being vented directly out of the room? If so then yes, we plan to use Adjust-A-Wing Reflectors and maybe a light spreader if that's recommended but otherwise open.

As I understand it, not only do we need to cool the heat from lamps/ballasts/other electrical activity to maintain a constant temperature (70F I've heard), we need to constantly dehumidify because of transpiration and evaporation from reservoirs (we're going to use RDWC). I understand that cooling/dehumidifying are very related, but I'm not an expert. Our HVAC system will be a closed, recirculating system so venting outside isn't an option (and yes we will be quite insulated). Under your recommendations, this 48,000btu system will cool and dehumidify adequately (with some extra-portable dehumidifiers)?

We are in consultations with an HVAC guy and he was asking how much humidity will be produced by the plants, which was difficult to figure out. Any advice on that front?