Aircon & exhaust fan

[brick]

hopefully this works....

 

an example of the type of AC I am using is:

http://t2.gstatic.co...fiFI9Fi2Coc7hMQ

 

it is a 'split system'. however both units are movable and perminantly joined by refrigerant hose (fixed)

 

Nice little unit you have there. Can you get some pics up with the whole set up as it is now. The whole grow room. Inside.

Maybe you may have to drop the perfectionist bar a couple of notches. The only a/c units that I know of that maintain almost perfect conditions ie: 22oc are in the prem babys wards in maternity hospitals that I have worked in.

Most everything else the temps can vary from 2oc differential (air in/air out) to 8oc or even higher.

Your unit is blowing the cold air out the top vents, straight up virtually. That is how they work for the best efficiency.

I would try taping a bit of cardboard across the top to force the air down (goes against the grain of heat exchange) in the space it should move the air around a fair bit.

Also remember that the a/c is dehydrating the surrounding air space, so your plants could need more watering than usual.

How cool a temp do you want. 26o is pretty good temp for cannabis

[greennoobie]

ok, so my digicam is an able to deal with the amount of light in there (not that keen on posting real pic's either).

 

attached is a *completely to scale* (plus or minus a few cm's) drawing.

 

with regards to the a/c and your suggestion about having the outlet pointed down, I'll give is a shot - see how it turns out... At the moment, there are 3 ducts I have put into the A/C (after ripping out the vains on the vents):

1x 100mm duct to mother room

2x 150mm duct to the flower room. The outlet of these are at the back of the osc fans (one at each end of the room)

 

 

All air coming in is from the outside world - since starting this thread I have gone and changed the air circuits to:

Cool tubes: own air

Environment: own air, 20min on 40min off - To see how the A/C copes.

 

A few thoughts.

 

I am currently fine with the temp of the mother room, actually its a little low - at 20 ish deg.

The flower room is sitting at 25 - 27 deg, but the ac wont cycle, its running 100%. If I could achieve this temp with cycling of the a/c I'd be (very) happy.

Might be worth while exhausting the air out of the shed completely, thus decreasing the thermal load on one wall and lowering the potential for hot air to be drawn back into the grow room (via doors etc - they are sealed, but nothing is ever completely 'leak free'!)

I've always thought that 25deg was the ideal temp, which is what I am trying to achieve, or atleast as reasonably close to it.

 

Also, re humidity, on a daily range, it is between 30 and 80%, but mostly sits around 50 - 55%, with spikes of dry and wet throughout the day.

[greennoobie]

image didnt upload....

 

(edit - again!)

Edited December 30, 2010 by greennoobie

[brick]

Ok thats good. First off and if possible relocate the air con away from the door or if not using the door, seal it up.

Ok I read it again. bit fucked atm.

It will be sucking hot air through the spaces/cracks around the doorway.

Do you run both tube fan and exhaust at the same time?

If so I would shut off the exhaust fan and have it come on when the lights are out.

You could be pulling too much air out to quickly. That may explain why the ac is not cycling.

Or you could buy a couple of those plastic thingos that you hang on the back door to keep the flys out. Put them between the tube and the air con. that would/may slow down the air enough and allow the ac to cycle.

 

Yeah get rid of all the heat sources. You only need a couple of those small whirly things on the shed roof and the breeze

does the rest.

You could have too much leakage of air as well. If the fans are pulling that strongly then they will be pulling hot air through every crevice in the shed.

[greennoobie]

just to clarify, the cooltubes are no longer drawing air from the grow room (changed it around a today). And unfortunately, due to the length of hose on the AC - I cant really get it any further away from the door.

 

I guess the next step is to continue sealing up the doors as thats the only area it can leak from. The walls have insulation batts behind them and the surfaces are tough and groove mdf. Unfortunately, due to the cramped area - I really need both doors!

 

Mmmm, if only real split system A/C's were diy!

[brick]

See if you can as gh (i think) suggested and put a fan speed controller on the exhaust fan. If you have a passive inlet vent then slowing down the ef may just allow the ac to do its thing.

[greennoobie]

well, after a few weeks of trial and error, I have come to the conclusion that:

1) I was drawing a fair amount of hot air from the hot side of the shed. Now mostly solved with foam sealant and weather strips.

2)The A/C isnt big enough to deal with the demands of the shed, lights out, mid-day sun had the temps rising without the thermal load of lights!

 

Solutions to consider....

DIY split system install

Co2 install (with better ac!)

 

I am currently trying to find a 'flexible' hose that can be used to attached the two sides of a split system without having someone come in to do it properly...

[brick]

well, after a few weeks of trial and error, I have come to the conclusion that:

1) I was drawing a fair amount of hot air from the hot side of the shed. Now mostly solved with foam sealant and weather strips.

2)The A/C isnt big enough to deal with the demands of the shed, lights out, mid-day sun had the temps rising without the thermal load of lights!

 

Solutions to consider....

DIY split system install

Co2 install (with better ac!)

 

I am currently trying to find a 'flexible' hose that can be used to attached the two sides of a split system without having someone come in to do it properly...

 

You can buy pre charged lines with splits. But if you don't have a refrigerant handling licence, I don't think you will get them. Can be complicated to fit unless you have some refrigeration experience. And dangerous, as the gas in liquid form can give severe burns if spilt/sprayed onto bare skin. In the eyes well forget it! You cant just fit any pipe work it has to be refrigeration quality copper tubing, then you would have to remove all the air in the pipes. Probably be cheaper and easier to buy another ac like the one you have and run the both of them.

[greennoobie]

my thoughts exactly Brick...

 

I am wonderin if a RAC aircon (window rattler) might work, with the hot side in the shed...

 

I cant see why not, the a/c I have has the compresser within the shed, and while it does struggle when it gets hot, it still works.