too cold during dark hours

[trailblazer2]

We live up in the mountains and its getting cold. Most heat is from woodstove and occasionally propane heater. Its a big house and we cant keep it very warm. Growroom is bedroom closet 6 x 6 feet and bedroom is one of coldest rooms in house, so run light 1000w hps during night. Works great and no worries about too much heat, but during day light is off and growroom gets down to 50 deg F . We cant use electric heater, electric bill is already too high. Any ideas how to retain heat during light hours to help it stay warmer during dark hours? Jugs of water? Rocks? These tricks are used in greenhouses, but need many gallons of water or lots of rocks to retain enough heat. Also, what problems should we expect from cold temps during dark hours? Lucky we dont have much humidity. Plants are just starting to bloom and lookin good so far. Growroom is closed off during dark hours... no fan and no ventilation. Can draw in fresh air, but it will be cold.

 

[Lapides]

Without being able to add a heater, I guess if I were in your situation, I would insulate the walls of the closet. It wouldn't be very expensive to do either.

 

[Granger2]

If I were to use water to store heat, the only way I would do it is to paint square metal stackable 5 gal cans black, and fill with water and bleach so they don't go funky. Can you leave the door open to the bed room during lights out? And really, it wouldn't cost that much to keep it, say, 65 during lights out with a cheap electric heater.

Also, I would not go hillbilly with the cans. They must not be bent up and they've got to have leak proof lids. Good luck. -granger

 

[GReen dreAM]

I have similar problem, and my solution is very easy, get another light <400/600> and do another grow box in the same room...which will be on during the day....can be another flow or veg space...very usefull... I have 2 rooms within big room, 2000W and 1000W they both Flo, so 2000W is on during night and 1000W daytime...






gd

 

[supermanlives]

when I lived in coldass area I vented my veg area into my flower area to keep temps up.i have also used heat mats to keep the root zone warm. had temps as low as 50 with no issues.

 

[AlterEgo860]

another flower room running during the day.. smaller light.. but vent into other flower back an forth.. keeps my room warmer

 

[Chevy cHaze]

Hey Trailblazer2,
I know from experience that if you keep your rootzone warm, the plants will tolerate room temps they could otherwise not live in. 50F/10C sounds low to me though...it seems to have worked for supermanlives though! but maybe do a search for root temp or similar ? electrical heat mats cost like 10-20 bucks, and won't blow you electricity budget. Maybe this could work for you if heating the entire room is too science fiction.

take care& good luck

 

[foomar]

Am not prepared to heat dureing the dark cycle in winter but have got round it in a few ways.

Moveing the veg in would probably be enough , a hundred watts of cfl,s works for me in a bigger room.

Switch to hydro and use a tank heater in the res , they can take near frost if the roots stay warm.

Box in and insulate pots with a soil heating cable of around 100 watts , always use warm water and they do well.


Lose some yield and they take longer to finish cold but the colours are some compensation.

 

[TheCleanGame]

---snip---

 

[BakedBandit]

Can you run ducting in from a warmer part of the house to the closet? Otherwise a second bi in the bedroom would be sweet

 

[Tonygreen]

a small heater is not gonna take up much electricity in that small room... How much do you pay per kWh?

Look at this...

http://www.walmart.com/ip/Optimus-Heater-Mini-Portable-Oil-Filled-Radiator-500W-H6002/15162310

That thing will cost you like 10 bucks a month to run during lights out. Sell a gram or two each harvest or something if money is that tight.

 

[trailblazer2]

Thanks to all for the advice. Might try heating cables... low power draw sounds good. Will also try jugs of water, but need at least 20 to retain enough heat. What about the issue of no fresh air during dark hours? There is a 1 foot square hole in wall but air is very cold because it comes mostly from under house, so could make things worse. Btw, we always use warm water for plants. We rent the house and cant just cut holes for vents.. walls are wood...sheetrock would be much easier to replace. This has been biggest problem in designing growroom. If we could duct warm air from woodstove area would be great and maybe supply extra co2.

 

[trailblazer2]

The weather has been mild and we tried a few things that are helping. House heater is a forced air unit with intake in main room with woodstove. By running fan only it draws in warm air and goes into other rooms. By closing bathroom door it makes more flow into bedroom. This helps alot. We have been running growroom fan even though door stays closed we have managed to keep temps above 60 def F. Plants doing well. Weather is starting to get colder so might still have issues, but harvest is about 4 weeks away so crossing fingers and hope for the best.

 

[foomar]

If we could duct warm air from woodstove area would be great

Am heating a bedroom by pulling hot air from an inglenooked wood stove to good effect.

Would suggest a carbon monoxide detector to be a worthwhile investment.

 

[il19z8rn4li1]

I make heat bombs and place them next to or in the middle of some pots.

Just take a fish tank heater that has a thermostat and control on it.

Get a bottle that will fit the tube portion of the heater all the way in.


Cut a hole in the lid of the bottle so you can slid the heater through the lid
and then screw the lid on the bottle.

Now silicon the heater to the bottle lid.

Allow to cure 24 hours.

fill with water, add few drops of soap and bingo bango, "heat bomb"

you can use a 3 liter bottle PERFECTLY with a nice 8-9inch heater.

Would be nice radiant heat.

Dont forget to black out the bottle, usually heaters have a red light when its working.
I use electrical tape

 

[foomar]

we have managed to keep temps above 60 def F

Growth definitely stalls out if root temps stay below 55f , dark cycle air temp can drop to frost without injury.

Just watch the humidity and never hit the dew point , always have powdery mildew when I get condensation within the room , and it seems to spread particularly fast at low temps from what I have seen .

Easiest option could be to switch to hydro for the cold season and drop a tank heater in the res.

 

[Wise]

Depending on your setup, you could draw warm air from your veg area into the flower area during the night cycle.

 

[trailblazer2]

update

update

Had to resort to using small ceramic heater, then found better solution... ripped electric blanket apart and used heating cable around pots. Works great! They love it, and its easy to adjust heat setting. We had reached critical situation before doing this... nutrient lockout and some powdery mildew. Plants are now very happy. Also venting closet during dark hours so air is fresh and humidity low. About the heat bomb idea... a small crock pot would be easier. I was going to actually cook some beef in the crock pot in the closet but my wife thinks im crazy. Maybe make some hard cider too... extra co2. Dinner, homemade swish, and a sample of small bud... sounds like a great evening. If I could afford it I would buy proper heating cables, but these work great and saved our ass.

 

[Tonygreen]

Its like 10 bucks a month to run a small space heater. Be careful of fire hazard man, stay safe and good luck.

 

[Jhhnn]

Several 5 gal buckets full of water will increase the thermal mass in the room tremendously. Black paint helps them absorb light. You won't really have any more heat than you do now, you'll just reduce the temp swing & make it more gradual going up & down. With sufficient thermal mass, the temp won't go nearly as low during the cool down cycle, nor as high in the warming phase. It may take a few days to bring the water up to temp in the first place. Whatever you can do to insulate the space will help, too, once you've achieved large thermal mass.

Wish I knew the math, but I don't.