cant get off 20c

bloody cold nights i was 27c perfect undrr led, but this frost has dropped me to 20c and 15 nights ive never had a winter this cold drop me so low, i min 18c nights normaly,
i need 27c for ca metabolisum, iv seen effects already happening due to lower temps, but if i put an oil rad in my humidity wil drop its already 40 with humidifier on filling it up every day.

i slowed the fans down pulling from in the house and they dropped temps more at night with ducting runnin the cold loft its like a chilleer,
any ideas before i purchase?

Guys swear by the oil filled heaters. They're very safe. Don't know how effective. If you could cover the tent with just a cheap tarp with one in the tent it would increase the heat inside. These shouldn't drop your humidity like an electric heater with an exposed element would.

I've just changed back to Hid for winter, when I add the cost of a dehumidifier and a heater led works out 30% more to run.

I got a baseboard heater 120/240V thermostat wired up and use that to run a heater in my grow room to keep the temp at 70 in the dark. With just a 400W CMH running it kicks in a little during the day too as my basement is chilly now when it's -33C out there. It's a 1500W heater but has two switches for 750W each and I just have one on. Dial on the heater is cranked max and the thermostat switches it on and off as needed. Even when it's this cold it only comes on for a few min at a time maybe 3x an hour so it's not using that much power. I put my power meter on it for a few days once to see how much it used and was pleasantly surprised.

Oil heaters work but they are slow to heat up. Conversely they are also slower to cool so should work as well. I have one but like the heater I use better. That little baseboard heater isn't wired in but will be once I get around to installing a 240V line in there. Didn't notice when I bought it and didn't hardly get warm when I wired it with 120. DOH!



If your exhaust is running 24/7 you should get a temp/rh controller for it and a speed controller is nice too then the fan runs quieter and only when it is told to by the controllers. Keeps the heat in too.

Some things that can be tried out:
-Extract from the bottom, from the coldest place in your growroom.
-Fuel burning heating will both heat and increase humidity but its hard to control with timers and such.
-Lower the light intensity a bit; yes you lose yield but generally not as much as if you light burn your cannopy. Raising the lights would be better than lowering wattage. Also drivers should be in your growspace and not remote.
- if you can find them at a decent price agriculture heating mats/pads directly under the pot: they heat the roots directly where it matters most. I think this is one of the tricks of @Moflow who imho is the cold climate led grow voodoo guru here on the forum. hope he can give away some tips. Ymmv

im extracting from base built a HVAC
intake in the top, coming from a 24/7 t5 cutting room to keep it warm,
hlgs are on 50% and 4ft away there fine perfect even.. providing i hit about 25c or up
fan set to min 40% atm, wont go ledd as it stops lol

thinking to add the oil radin the cutting room close to the grow rooms extraction put a bowl of water on it lol

damn its cold, i did have a load of curtains up, all around and kept my vent up there , but nayber said there is no frost on my roof
its not due to the grow tho,, its just a coincedence as i have thermal walls 3ft thick, so it pours heat out the roof, and as i am insulated out in a box , that escapes lol just so happens i do grow too, same thing happened when i didnt grow so.. made me paraoid tho so took down curatins and vented outside

As you all pick yerselfs up off the floor laughing....
Anything is possible. Just believe..... lol
I laugh in the face of 'optimum' growing conditions.
Some insulation thrown over the tent.
Heatmats and polystyrene.
The soil temperature is a cosy ~ 21°C - 69°F, I checked it with a meat temperature probe.
Air temperature at the canopy is around 14°C - 57°F
3" - 75mm 12 volt pc fan on a manual speed controller for extraction, 4" fan n carbon filter recirculates air in the tent.
Not bad for 200 watts of led light in this 4ft x 4ft tent.



And if you think that's bad yous should see my veg, clone, seed growing area up in the attic.
Warm roots does the trick.

This is highs of 22C and lows of 18C and the gauge is on the scrog screen.

I use a small tubular greenhouse heater 80w where my circulation fan is to the right.

I’ve also blocked my external intakes and I speed control my fan.

Don’t discount (if you can) removing the driver and mounting It lower in the room so you get heat moving through the room if needed.

hotrodharley said:

Guys swear by the oil filled heaters. They're very safe. Don't know how effective. If you could cover the tent with just a cheap tarp with one in the tent it would increase the heat inside. These shouldn't drop your humidity like an electric heater with an exposed element would.

Click to expand...

If the heat output is the same, the RH drop will be the same.

Billy the Mountain said:

If the heat output is the same, the RH drop will be the same.

Click to expand...

Wrong

"Radiant space heaters do not lower the humidity or create wind speed. This is their strongest attribute. However, since they heat objects, then the objects heat the room they are slower to raise the overall temperature although you may feel comfortable with a lower room temperature. If you or a small area is all that is need to be heated then a radiant space heater is the best choice. If you have a large living room to be heated for a shorter period of time then a convection space heater may be the best choice."

Article Source: http://EzineArticles.com/1715907

Read about radiant versus convection heaters.

You've piqued my curiosity. Please explain how any heater can raise the air temp without lowering humidity?

Billy the Mountain said:

You've piqued my curiosity. Please explain how any heater can raise the air temp without lowering humidity?

Click to expand...

Theres one situation where i can see this as possible: if the radiant heat is acting directly on the leaves of you plants these will heat up a bit more than ambient which in turn leads to higher transpiration which can offset the lowering of RH. I know, a slightly marginal case but it could explain why this could be seen. But yeah, youre right: of ambient temp goes up and all else stays the same RH has to go down as hot air can carry more water, which means if the absolute quantity of water in the air stays the same then RH must go down.

Yeah, that's the relative part of RH

hotrodharley said:

Wrong

"Radiant space heaters do not lower the humidity or create wind speed. This is their strongest attribute. However, since they heat objects, then the objects heat the room they are slower to raise the overall temperature although you may feel comfortable with a lower room temperature. If you or a small area is all that is need to be heated then a radiant space heater is the best choice. If you have a large living room to be heated for a shorter period of time then a convection space heater may be the best choice."

Article Source: http://EzineArticles.com/1715907

Click to expand...

In that article oil-filled heaters are listed as a convection type of heater.
"Convection type space heaters warm the air which in turn warms you. Included in this category are baseboard electric heaters, oil or water filled radiator style heaters and basically any type space heater that burns a fossil fuel directly. Imagine standing in front of your home's centralized heating system outlet and feeling the warm air rush over you but at the same time your kitchen counter tops are cool to the touch. This is convection type heating."

Article Source: http://EzineArticles.com/1715907

Yeah, its basic physics. If the air temp rises, the RELATIVE humidity will drop due to the higher water-carrying capacity of warmer air.
It doesn't matter if the heat source are lights, oil-filled, forced-air over a heating element, etc. If the air temp goes up, the RH goes down.

very interesting, so the humidity remains the same, but the ammount it can hold increases, just gona ramp up the humidity in the veg cab then humidifier on full and plumb it in to a tank of some kind cause i fill that more than i need to water plants ffs ..

will get oil rad tomorow,
you always assume the heat drys the air out, not that it increases the area to be filled to say.

so basicly ur saying it doesnt matter if the heat rises from the oil rad or the temp outside ..the humidity will have been about the same ?
summer seems more humid than winter tho but isnt that due to convection effect of central heating evaporating everything and with it cold outside it pulls it out fast with the water . we end up heating a dry enviroment

No

The relative humidity decreases with an increase in heat. Heat does indeed "dry the air out".

Hot air can hold more water than cold air (this why dew forms when temps go down at night, the water forms drops when the cold air cant hold it anymore). So the absolute humidity stays the same (total amount of water in the air) but since the hot air can hold more water the relative humidity goes down.

dont go mad if its below 27C.
i prefer above 25C myself but they never do bad as long its clearly above 20 (i seldon to never have a temp below that during day, cant say therefore).