Here is the situation. we had to move everything to a new location. This forced us to build a enclosure. Here is the equipment relative to our issue. 1X 1000W air cooled HPS/MH 1X 10,000BTU Air conditioner unlimited fans and duct work. Before this was set up in a 10x8dt. room and all we ever had to run was the the fan for the light, and vented that to another room. Temps never reached over 75degF. We actually had to run a heater during the night hours. So we found a very similar location and set everything up. This time due to other factors we had to build an enclosure that it 6'x6'x7' (see attached) Everything is set up and a test run was made. After running a MH light for 3 hours the floor temp was 85degF and the temp at the light was 90degF. We did not run the air conditioner as we did not have to run it before and were hoping that it would not be necessary again. We will be testing with the ac unit tonight. So here are my questions. 1. with running the AC will we have to still exhaust air from the room through the proposed vents highlighted in red? (AC pulls air from inside the room and exhausts hot air out of the room) 2. What could be done to further cool the area around the light? 3. Should one of the suggested vent areas become a cool air intake to the room? (will running the AC be enough) 4. What is the most optimum position for the Room heat exhaust? Additional facts: Room temp out side the enclosure stays at 68degF, and only drops about three deg at night. The enclosure dimensions can not be changed, not my call.
With a window AC I would put in a air intake near the bottom and for your light I would vent that out up high. You want to pull cooler air in down low and vent hotter exhaust air out up high. I wouldnt put both the cooler air intake and the hot air exhaust on the same wall. Vent the hot air outside if possible or like up into an attic or tap into like a vent in the attic that vents to the outside.
the ac unit I have is a portable and takes in air from inside the room and exhausts the heat out side the room. Do you think moving the heat exhaust to the other wall and connecting it to the light exhaust outside the unit be sufficient. (the exhaust from the light is already ducted to be moved out of the outside room (room in room setup)) and thanks for the help so far.
In your previous room, did you have any ventilation for the plants? From your description it sounds like you didn't, but maybe your cool tube was open on the intake side, and there were cracks in the room? About your diagram, I don't see any ventilation for the room except for the a/c. Without the a/c, you need to have an exhaust fan for the room & plants, and an intake hole, preferably located diagonally opposite the exhaust fan, near or in the floor. I would think you'd need this even with the a/c, but I don't have experience with dedicated a/c in the room. The fan on your cool tube should be on the exhaust side. May not be a huge difference, but fans are better at pulling air than pushing air. Another help would be a floor fan blowing on the light, towards the room exhaust. If the outside temp is 68 I think you can make this work without the a/c, but you need exhaust and intake for the room.
More info. In the old room we had alot more space, and the cooling fan for the light was pulling/pushing air from in the room to outside of the room, along with a room fan this was able to move excess heat from the room no problem. So the entire room was vented through the light, and had a single intake coming from a basement into the room. The new set up is not complete but still in works, in the pic everything in red is the proposed intake and exhaust, but nothing has been cut yet, just wanted a bit of advice before. As far as the placement of the fan is concerned, I think I have it covered as we will be installing a booster fan on the exhaust side of the light to help move that air (good tip though). we use the intake fan to ensure cool air (68degF from exterior room) makes it to the bulb itself, the booster fan should move the heat, was a precaution, we delt with in the past the worked very well. For the new intake and exhaust, I was thinking moving the exhaust to the upper right of the enclosure (bottom right in pic) and moving air in the room at the lower left (upper left in pic) keeping the intake at the bottom of the grow as cool air tends to fall. I too have never used a airconditioner in a setup bu twe ahve a standalone unit that will send the warm air out. I would prefer to not use the airconditioner if it is a possability, so any more suggestions would help alot, and thanks.
So running the ac unit worked and the temp is now down to 75degF. We are still trying to eliminate the ac unit completely which I know from previous exp. can be done. So we are thinking of replacing the current light exhaust fan with a larger 250CFM and removing the glass from the reflector. what do you think? (Blue) Currently there is 2 50CFM fans running at the light intake and exhaust with the glass in place. will removing the glass allow for more heat to be sucked out of the room? or will the removal of the glass cause more heat to be transferred into the room? and thanks for the help in advance. also here is a pic of the last harvest from the old room. going for like results.
I think removing the glass will transfer more heat downward and into the room. Also a bigger fan for the light should help. But if your doing trial runs it cant hurt to give it a try.
I agree with tplat about the glass, but no harm in trying it. To eliminate the a/c, I would put the 250CFM fan in one corner, near the ceiling or light level, and a vent hole in the corner diagonally opposite. If you look around at other grows of this size you will get some good ideas. You might need more than 250CFM, not sure. It seems that you want to use the light as your sole exhaust, which may not work in this room, but since you're in testing mode you should try it. But venting the plants separately from the light will give the plants more ventilation, which is always a good thing. Nice cypress-like bud!
testing done and everything is in order. Had to change things around a bit but everything is perfect. 40-50% RH 78F max canopy temp Using the AC unit actually cut out the humidity problem that our last room had. Though a second exhaust had to be used for the ac. Thanks for all the input!
yes I got two, one is used on the light pulling the air into a separate room. the other is in a duct that brings coon air into the room from a basement room. it kinda looks like the updated pic. couple things learned though. 1. you can not vent the light fan and the AC through the same duct. (the AC exhaust will push hot air back up to the light. so there are two exhausts one for the light and one for the AC. 2. you can vent portable ac units out side if you use home made carbon filters, that will not slow the ac unit. (see attached) I used dryer sheets and created two all carbon 1in thick filters, then using a 4in dasani bottle, top and bottom cut off attached one of the filters and stuffed the void with carbon pellets and dryer sheets then attached the other filter. this allowed me to vent outside and have it smell like I was doing laundry (lavender in my case) 3. the intake fan from the basement blows cool fresh air into the enclosure, it adds a bit of moister air into the room and keeps the AC from running constantly, the AC only comes on about every hour or so and shuts off again after about five mins or so. so it basicly pulls that excess moist air out of the room with the accumulated heat. and the fan is replaceing the air in the room every time the AC kicks on. A nother thing that I have added are CO2 bags. you don't need a expensive CO2 gen. that is going to heat up your room and cost you money. I bought one of these in the last set up and it kept my room at 1200PPM and they last about 6 months. I added a new bag and ran test all last night and while the AC unit is off I stand at about 1200PPM CO2 when it kicks on it drops to about 900PPM CO2 then rises again after five mins or so. these don't release on a timer so it is constant. but I have used them in the past and had smashing results, and will continue to use them. and as a bonus they are really cheap in compairson. ExHale CO2 Cultivator (Natural CO2 Generator) - EZ Hydroponics & Organics Will post grow journal after the sprouts get a little bigger. This batch willl contain cheese BC bud Caramelicious thanks for all the help. and here is a pic of the last batch.
Wow! Thanks for all that useful info. Those CO2 bags are very cool. Someday I'll have a bigger grow and I may use some of your ideas. I'm sure you're heading for more cypress tree buds!