Controlling Temps & Humidity through indoor day/night cycle

[malakkar]

Hi guys!

I am running hot on a small problem here.

I'm planning on starting a grow this winter. All problems thus far appear solved except one thing: I cannot control the temperature in the room that is to contain the growbox as the power output of the central heating unit is not predcitable. My prediction is that during harsh winters temperature is going to fluctuate between 17°C and 10°C.

Now during the day cycle in the box there isn't really a problem, the wattage @400W is a little over the top for the small space (3.85 square feet). During night however I fear to give the plants a cold shock. How would you alleviate this as primitively as possible? Keep in mind that the room temp cannot be controlled.

Furthermore I need to keep humidity at around 55% during night. I'm looking for a way to do this passively as I'd like to avoid investing into a digital hygrometer and a switch for switching ventilation power from 100% to 30% once humidity reaches 55%.

So, in a nutshell:

Keeping temps above 16°C and humidity around 55% while facing the challange of incontrollable environment temps. All this using a simple setup.

Current paramaters:

400W sodium lamp
3.85 square feet area
Ventilation 12200 cbf/h
Box height: 4.6 feet

 

[Hogdady]

Fluid filled heater?

 

[malakkar]

I found the following to be a solution:

An electric thermostat replacing the old one on the radiator will measure the temperature in the room constantly and opne/close the valve accordingly, depeneding how much heat the lamp and aplliances emit.

As for humidity: I haven't really found a solution for that that doesn't involve huge costs. I'm beginning to consider decorating the room with pot full of water to achieve a high surface area for incidental evaporation.

 

[burrr]

I would suggest using a simple room heater, the 25.00 kind, with a built in thermostat. use that to keep the temp above 60 during the dark cycle.
For humidity and heat control i would suggest some sort of climate controller, like this Indoor Climate Controller - $119.95 : neHydro.com, Hydroponics and Gardening Supplies

or this
AIR-3 Temperature/Humidity Controller [AIR-3] - $189.95 : neHydro.com, Hydroponics and Gardening Supplies

these will work with your co2 system when you add one down the road.

 

[nwgrower]

i have the same thing going on. small box 4'x4'x5' out in the shop(no heat).now this might not be the best idea butt what i did for grow (high humidity)2 coffee cans hot glue a 12"x1" wooden dowel standing in the middle hang a hand towel ever dowel and into can fill with water as needed.water wicks up towel. depending on how i aim my fans humidity is 70to 80%.bud just remove cans drain and fill with that stuff thay sell at the rv and camping stores to absorbe moisture. now this is whats working for me i took my air intake and ran it threw a metel trash can sitting next my box next i put a space heater in trashcan (METAL CAN)and conect it to a remote thermostat in the box.heat stays even and no pre burnt buds. we just went through a cold spell my incoming air was 4f and temp never got below 70f in box with the 400 off.i hope this helps im new to this but its working good so far

 

[Giantsfan24]

Would a horticultural seedling propagation mat work for temps? I hope so, I just ordered one!

 

[Giantsfan24]

Would a horticultural seedling propagation mat work for temps? I hope so, I just ordered one!

And it's working great for my small stealth grow space...highly recommended!