Air conditioning

[thc24]

thanks Pa ul, very helpful the portable units usually dont switch back on after being turn off by temp controller, But all A/c dont like beinh turn on and off mine in the instructions says 3 times on and off max per day .

 

Under ground vents here so the hot air is little issue as it comes out 10 meters away from a moded ceramic pot.

[Gazza2001au]

Under ground vents here so the hot air is little issue as it comes out 10 meters away from a moded ceramic pot.

lmao wouldnt this be a spinner on the FLIR

why dont u use the thermostat that is built into the A/C to control temps? maybe i missed something

[pipeman]

Its important to realise that just because your airconditioner blows air out from the outside that it is not actually air being expelled from inside the room it is cooling, it is a function of the compressor. All wall/split system airconditioners just recycle the internal air, don't think you are getting any internal air replacement just because the arse end of the unit hanging out your wall is blowing air outside.

 

That being said the main reason for the massive amount of ventilation required in the average unairconditioned growroom is temperature and humidity control. With aircon involved these are greatly reduced and the amount of ventilation required for co2 replacement is relatively small. Like opening your grow room door a few times a day would likely be enough, or if you had some air leaks in your room. Another advantage of minimal air replacement is you could use co2 either from a chemical or bottle source to great effect...

Edited February 23, 2006 by pipeman

[thc24]

Gazza hi mate,

My A/c was cheep $250 only turns compressor off fan keeps running and is not accurate about 6c range from on to off, i use a temp controller as i need fans to move cool air from room into two seperate veg rooms and a flower room, inlet fans are only on when A/C is on. Actually working towards the co2 had a go a while back with dodgie reg and hose with holes. . No effect but rarely turned it on . Home made evap coolers work i had one for years i like it over A/C no noise but needs water and pump but no good for flower (can take a pic but its in peices youll get an idea but).

 

Under ground vents, dont bother means more fans, i thought it was a good idea 12 months ago . Air should be cooler? NO not so when using strong fans pulling air fast though my shed . Shed looks normal no vents visable . Going to be filled in soon as the ground and bricks above ducts are sinking , mostly but will keep the u shape 300 x 200mm connectors to go under shed rather that through.

 

Pipe man there are exhaust fans there also A/C for summer days when plants are sleeping and for the veg rooms. Flower room is fine pulling night air only comes on over 30c which happens maby once a day for around midday an hour or so back to 23 to 25 c . HUmidity A/C sure do help but growing at night lowered my RH well also , Moisture seeping through the floor is next issue, should have done it when building shed but need some moisture stopper , got some panda on the ground but not enough. Fast air removal is most important in this box.

Edited February 23, 2006 by thc24

[stonedstump]

Thanks pipeman

 

I may end up getting my second air conditioner afterall

[thc24]

Hi treestump ,

You should be able to run just one cooler with upto 4 to 6 x 600wts. Lights produce some heat but with a strong exhaust fan on carbon filter (best option) sucking from opposite end of grow box to inlet you should have no probs, are you getting 40c+ days?. Inside grow box use one oscilating fan per light to mix air within grow ,oscilating fans do nothing for air flow just movement within room, 300 mm inlets into grow box may need two if doors are sucked into room. Can use a cheep bathroom fan with 3 feet duct pointed towards A/C does not need to be stuck on as you want to cool the room the grow is in.. When A/C unit was used within room wind burn was a problem or not happy with the gas,. If its still hot add another exhaust punping back to room it will bring in more cool air faster . This works for me but may not for you i had to try alot of variations.

 

Sorry can give a complete answer to your q , I think a carbon filter with a fan sized to number of lights x grow areax climate min and max yearly. imaby a small evap for emergencies on some sort of controller will do, in a few weeks you wont need it really. Temps upto 33/35c are ok in summer raise lights 15 cm with a fan to mix the air.

 

A tip i once got is you cant have enough thermometers min/ max are best i use 4 one for the room that houses eveything has a probe so temp from celing and floorand away from cooler the rest are in grow under/in canopy , above lights/hanging 10 cm down from shade. With all the readings you get you can move fans around to remove hot spots and inprove flow while getting even movement. Sorry guys not much of a writer.

[stonedstump]

th24, yeah I have an evaporative cooler which works fine for my small grow room but I want to move to the shed soon and I am afraid that with a 1000w MH it will get hot in there during summer and even winter in QLD.

 

I was thinking my intake/out-take fans (proper ones about 30cm) may not be enouugh?

 

It may be ok if i have one at one end and the other at the other end, should have good airflow but i'm still abit paranoid the temps will rise, and I can't have it running all night, I only want to run during the day until around midnight or so.

 

I am using a labaratory grade digital thermo-hygrometre at the moment to take my temperatures buy I will still get a couple of cheapies to put in there probably

 

If I get an air conditioner I will be getting a cheap split system for $290 at a discount electrical chain near me, 1kw of cooling should be enough for a 3x3m shed. If that is the case I will probably do as someone said and just have one exhaust fan which should equalize the airflow.

[Pa-uul]

one exhaust fan which should equalize the airflow.

If you are getting a split-system then it will not exchange air for you. It does not exhaust air so there is no difference in pressure to equalize. All you will need to do is vent the air perhaps several times a day to let in new oxygen and carbon dioxide, but in general you want the room sealed if you're keeping the a/c on 24/7. Like pipeman says:

...Like opening your grow room door a few times a day would likely be enough, or if you had some air leaks in your room....

If you’ were to add Co2 as well you could keep the environment even more isolated than opening the door several time a day.

...the portable units usually don’t switch back on after being turn off by temp controller, But all A/c don’t like being turn on and off mine in the instructions says 3 times on and off max per day...

…use the thermostat that is built into the A/C to control temps? maybe i missed something 

The air-conditioner will have its own thermostat to regulate the temperature. I would be thinking about leaving the air-conditioner on 24-hours a day.