Results 1 to 5 of 5

Thread: How to Cool a Grow Room Cheaply

  1. #1

    Join Date
    Feb 2010
    Here, Where Else..?
    Thanked 1,739 Times in 927 Posts

    Default How to Cool a Grow Room Cheaply

    I found this tutorial on how to help with heat issues in your grow rooms surrounding area where it can get very very hot just as it does in my concrette shed I am also looking for a cheap easy way to reduce the heat signatures in my shed before the police helicopter's IR (Infra Red) pics up and they bust my door down

    If anyone has any info on this then please by all means add what you can and lets help keep everyone safe from the eye in the sky

    Grow rooms can become too warm because of heat given off by the lights, and they can also get hot just because of the surrounding air temperature. Just like with your house, there are ways to cool it that don't cost a lot of money.


    Things You'll Need:

    * Insulation, and tools and materials for installing it
    * 2 exhaust fans, ductwork if necessary, and tools and materials to install
    * Timer (optional)

    Step 1

    Insulate your grow room. This is especially important if the grow room is outside or if it is in a location where the surrounding air frequently gets hot. There are many kinds of insulation; which you choose depends on the shape, size and construction of your room and on your budget. Buy rolls of fiberglass insulation and install it between the studs, then cover it with plastic, drywall or particle board. You can also spray foam insulation into cavities between drywall or plywood. This is a good method if your walls are already in place. Cut a small hole in the drywall and spray in the insulation, then cover or patch the hole. Do this for each cavity (between each of the studs).

    Step 2

    Install exhaust fans. Place one fan at the top of a wall or in the ceiling, blowing outward. This fan will remove the hot air from the room. Place the other fan low down, at the base of a wall (opposite from where the top fan is located, if possible) and aiming so that it blows air into the room. To install fans, cut a small hole in the wall. Reinforce the edges with wood, or cut the hole near the wood framing. Attach the fan to the wood with screws. If the surrounding area is a room that can become quite hot, consider running ductwork to the outside. If you don't want to run ducts to both fans, opt to provide them for the lower fan first. Provide a source of electricity.

    Step 3

    Set the fans on a timer or a thermostat. The timer is the least expensive and easier of the two options. Observe the room around the clock to note the temperature in both the room and the surrounding area (or the outside, if the room is outside or if you attached ductwork to the intake fan). Set the timer to turn on when the outside air is cooler than the air inside the room, and to turn off again when the outside air is hot. For most areas, that will probably mean running the fans at night and turning them off in the morning, but this will depend on time of year, location of the room and the climate of your area. Adjust the timers as the seasons change. You can also attach a thermostat that measures the air temperature inside the room and turns the fans on when it reaches a certain temperature.

    Step 4

    Provide shade for your room. If the room is in a basement or attic, cover the windows to keep sunlight out. If the room is outside, consider moving it to a location where there is natural shade from trees or a nearby building, especially in the afternoon. Purchase an awning or rig up some shade with a vinyl drop cloth to keep sun from hitting the room if it is built outside.

    Tips & Warnings

    Always run both fans at once. The principle is this: you are removing the hot air, aided by the fact that hot air rises, and replacing it with cooler air from outside. This is why you don't want the fans running during the really hot part of the day, unless the temperature in the room is still warmer than the outside air at that time.
    Complete DIY Start to Finish Grow Room

    Key Points Of Harvest Time

  2. The Following User Says Thank You to Wrams For This Useful Post:

    up2nogood (26-05-10)

  3. #2
    Chicken Champion! Yeti Sports Pentathlon Champion!
    Join Date
    Oct 2009
    Thanked 16,737 Times in 10,162 Posts


    good tips there people..
    Looking for New Pastures

  4. The Following User Says Thank You to up2nogood For This Useful Post:

    Wrams (26-05-10)

  5. #3
    Icon Guest


    Great Advice Wrams.
    It is no doubt the time of year when these forums start getting busy with people wondering how to combat the heat build up.
    I will just add a few notes that may help
    Heat build up during the summer months is a nightmare for many growers and is perhaps of minor consideration to most nuube growers when opting for the loft as the optimum location for growing
    If you can then grow in a basement or a box room it is so much easier to retain the optimum temps.

    Depending on your grow room location and also the setup of your grow room depends on the optimum strategy for maintaining temps.
    The two common methods in the loft would be an enclosed room such as a tent or homemade cabinet
    The alternative method is to have the loft as the grow room and hang lights from the roof and place reflective sheet around the plants as they develop

    If you are using a tent or cabinet then this is better then using the loft but it restricts space/access
    If you use the loft alone then this causes large heat signitures

    The best insulation for your loft or Grow room is a product called SF19 (available from most big builders merchants of roofing suppliers) this is like a roll of bubble wrap covered with silver foil and other layers in between it is about 1" thick and it can be tacked/stapled in place, it is much easier to use then fiberglass which is no good for insulating the roof, only laying on the loft floor which is no good to us.
    The alternative is to use Rigid Insulation Board fitted to the roof spars, problem with this is 50mm thick RIB is tricky to fit, awkward to get into your property, plus it decreases your height. which is usually vital in loft grows.

    If you are using a tent then best advice is replace all the metal poles with a timber frame which is just a few bits of 2x2 then line it with SF19 you can staple the sf19 to the doors of the tent so it still works the same only it is insulated from the inner loft space if your a keen bean then you could also SF19 the outside of the tent.

    Ok if you have got your tent/room as insulated as possible then we need to consider air flow
    Heres where I disagree with Wrams
    The fact is the air outside will never be as hot as those HPS lamps so simply sucking cool air from outside in at the bottom then extracting the air into the loft space around the room is not best practice.
    No amount of insulation will stop that from over heating, also you are increasing the heat signiture of the entire roof space.
    Primary goal is to get the hot air out of the loft.

    What you want me to explain how to get air out of loft for you know?
    This is the only realistic way of avoiding a heat signiture i can think of and it may not suit everyone.
    Make a new loft hatch if you have to but get one you can cut a chunk out of then run ducting from your extractor to the hatch, you can put a grill over but it will make a lot of noise with the air rushing through it, but its handy for covering the hole if you have visitors (fan will need turning off though)

    The next way of doing it is via a Vent which can be fitted through the roof but obviously this gives a heat signiture OK if you can make it like a boiler flue?
    Also consider knocking some bricks out of the chimney stack and venting though that.

  6. #4

    Join Date
    Mar 2010
    In the loft
    Thanked 2,947 Times in 1,970 Posts


    The way I extract in the loft is usually, I look for a decent enough roof tile or two that is a bit knackered and intake/extract there.
    Worked in both my current loft and my last one. My last one it went down into the wall cavity, this one it goes straight out of a dodgy roof tile.

  7. #5

    Join Date
    Aug 2010
    Thanked 0 Times in 0 Posts


    Thanks for sharing these great tips! This would really be handy for all growers, especially those who are just starting out. Doing all the great tips you shared will also benefit other plants not just cannabis. Great!

Similar Threads

  1. Replies: 212
    Last Post: 19-12-10, 11:37 AM
  2. My living room window grow :) First grow
    By Bammbulance in forum Abandoned Diaries
    Replies: 17
    Last Post: 21-09-10, 10:42 PM
  3. Easy way to feed your hydro grow. And its cool as fook
    By Munkeyboi in forum Hydroponic Growing
    Replies: 4
    Last Post: 05-08-09, 06:25 PM
  4. grow diary low ryder 2's pc setver grow room 250w cfl
    By green grass in forum Completed Grow Diaries
    Replies: 72
    Last Post: 08-06-09, 11:37 PM
  5. Replies: 2
    Last Post: 12-12-08, 09:13 AM


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Bonza Seeds - Over 2000 Strains!     |     bongs - herbtools     |     25% off Cannabis Seeds at Dr Chronic     |     buy a bong from Herb Tools     |     GYO Seedbank     |     Buy Cannabis Seeds Disclaimer - You must be over 18 years old to view/use this site does not encourage growing Cannabis or possessing Cannabis. Learning how to grow Cannabis instructions should be for educational purposes only. All Information contained in this web site is for: Historical reference, Scientific reference and Educational purposes only. Visitors to this website are advised against breaking the law as It is illegal to smoke, grow, or possess cannabis in the UK