Utility Room Grow - Ventilation Dilemma...Need Some Advice

Discussion in 'Grow Room Design/Setup' started by growtender, Nov 20, 2014.

  1. #1 growtender, Nov 20, 2014
    Last edited by a moderator: Nov 20, 2014
    Got a finished basement with a small 90sqft utility room that houses both my baseboard boiler and my water heater. It shares walls with my office and the living room. Perfect space for my small 1kw HPS hydroponic flowering setup. I did a grow down there over the summer and the temps stayed manageable.
    Now that it is winter, that room gets pretty warm with the boiler kicking on. I have it exhausting out the window with a larger passive intake from the office into the grow. Problem is my temps just aren't getting low enough and my humidity is around 10%!!
    Here is my current setup:
    ImageUploadedByGrasscity Forum1416499131.166350.jpg
    Temps are in the 80's and dry, and I think the main reason is the intake is pulling already warm air into the grow and that air is just getting heated by the boiler and not doing much to cool it down.
    I'm also thinking that I'm wasting a lot of good heat by exhausting it out the window, which in turn is pulling heat out of the house, which is also urging the boiler to kick on more often, keeping the grow too hot and costing me more money in a viscous cycle.
    The current system doesn't affect the draw of the boiler and water heater stacks, and I've smoke checked them and also have a CO detector installed in the room in case.
    I'm thinking of changing the exhaust to blow into the office and having a damper-controlled intake vent from the window to bring in outside winter air to help cool it down. I also am going to install a Titan fan temperature controller so that the fan kicks on only when the temp gets close to 80, which is great because I bought the thing a year ago and finally have a use for it!
    This would be the new setup:
    ImageUploadedByGrasscity Forum1416499323.647789.jpg
    Anyone see any potential problems with this setup? I feel like I'd be saving money not only by conserving heat but keeping the boiler from kicking on as much.

  2. You should not have a fan sucking the air from your utility room with combustion appliances into the house unless they're sealed systems with air intake+exhaust to the outside which you do not have. Doesn't seem worth the risk, even if you have a CO detector.
    What if you in the winter you used a separate fan for cooling the light with an air intake coming from the living room and blowing back into the living room, and then have your separate carbon vent going out the house. Then you would be blowing warm air from the light into the house without adding negative pressure to the room. If you put a passive air intake (no damper needed) to the outside in the office for makeup air, that will keep the exhaust fan from sucking all it's air from around windows and doors in the rest of the house and will temper the air with house air before it gets to your grow. That could also help keep the boiler from kicking on some by adding heat to the living room and confining the makeup air down there. I say no damper needed because with an exhaust fan going it will draw air from elsewhere if you don't designate a place and in theory no more air will be coming in than is going out, but you could use a barometric damper if you want it to only open at a certain negative pressure like only when the fan is on.
    As for humidity, you are sucking dry winter air in by blowing air out, you could make up for that with a humidifier.
    Also, insulating the exposed hot water pipes with decent self sealing pipe insulation and insulating the water heater can help keep the heat down in there. 
  3. Hey growtender.
    I'm jealous dude...lol. I have a very similar situation...except that I don't have a window in my utility(unfinished storage) room. I'm considering adding a cold air return from my a/c unit in order to get fresh air in, and exhausting out through a wall to the rest of my house. But I'm not sure if this would work.
    I have 2 drawings of my setup. Not trying to hijack your thread...but I'd love to get your input on what options I have to get this going.
    Thanks in advance!

    Attached Files:

  4. 85 solutions to a common problem.

    Simplest answer, in my opinion, boils down to redneck engineering.

    A bunch of ways to accomplish this.

    My favorite being putting quart milk jugs in the tent/area and dropping a small chunk of dry ice (can buy at most grocery stores) in them every couple days, while they're half full of water. Raises humidity, and chills grow area, plus augmenting CO2

    But just as easily, you can spend $3 on a 6 gallon bucket from Home Depot, an aquarium pump designed for a 20 gallon fish tank, some air stone tubing, some flexible copper tubing (1/4 inch soft copper), and a few small band clamps.

    Put the water pump in the bucket. Use the attachment for it that lets you slide the air stone hose over it. Band clamp it. stretch that hose to the opening of your area's intake. Make a coil of the soft copper...one that has 10 or 12 coils wide enough to fit comfortably in the accessway/duct, with a bend that returns the line. band clamp it together. Leave the "return" end of the copper line hanging into the bucket. All the way at the bottom of the bucket, if possible.

    Add ice or dry ice as needed to chill the water enough that air being drawn through the duct gets cold enough.

    NEVER blow INTO your area if you have heat issues. Compression creates heat, decompression cools. What happens to a bottled air can as you blow dust out of your computer with it? Gets damn cold, tight? It's venting gas to the outside--decompressing. You can create fire by placing two pieces of flammable solid against each other in a screw type vice, and tightening. Blow air in, you're raising air pressure---creating heat. Suck it out, the tent's lower pressure than outside. Therefor cooler. And the air coming into the area due to pressure imbalance expands rapidly to fill the volume..cooling it (and the area).
  5. Thaks for the input Indie! So with the milk jugs, would I need to hang/place those jugs above my plants? Also, I guess I'd need to get a ppm meter to test their ouput. The burners make me nervous. This sounds like a pretty simple solution in comparison to finding a way to exhaust...and my wife would appreciate me not cutting holes in anything. :hello:   I'll give it a shot.
  6. I just put them on the ground between the plants. My reasoning being I want as intense cold low down as I can manage, since in nature, soil averages about 50 degrees at that depth. I figure we're trying our best to deliver as close to outdoor natural conditions as we can (at least those aspects the plants make use of), so given any opportunity to influence the system to be more "natural" in effect is better.

    And no, no need for a ppm meter...another cheat...takes some math. Sea level CO2 is 400 ppm...or .04% of the atmosphere. calculate the volume of dry ice used (which is ALL carbon dioxide) to be .04% of your total volume. It won't all vaporize in one minute (usually not in one day...chills the water so much as to slow the reaction). So in a 4 by 4 by 4 tent, 64 cubic feet, you basically use a 4 inch by 5 inch by 2 inch (.0256 cu feet) or equivalent chunk of dry ice broken into fairly equal size pieces, and distributed in the water jugs.

    Do that every 2 to 3 days, your risk is too MUCH CO2, which generally is harmless to the plants, unless it just gets ridiculous. Just opening the door for 15 minutes a day, while you tend to the plants solves that.
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