Sealed vs. non-sealed room - Total energy consumption vs yield

[HendrikOl]

Hi,

I was wondering how often an AC will kick in, in a sealed room with a CO2 burner and aircooled hoods.

I live in central europe so the climate is mild year round. Average monthly temperatures range from 2°C/35 F (January) to 19°C / 66F (July), in most months it stays below 15° C / 60F.

Due to the aircooled hoods I would assume that the ac would barely if at all kick in if the outside temperature stays low enough?

If I am correct which outside temperature is cold enough so that the aircooled hoods can be cooled so that the AC barely kicks in?

What are your experiences?

I am also limited on energy consumption and I already read that often it makes more sense to just add another light in a non-sealed room to increase yield instead of wasting the energy with a sealed room and its AC.

However I assume that there must be a break even point (Wattage of lights) where a sealed room with AC, Co2 and aircooled hoods will outperform a non-sealed room even if it means peace of mind and less work involved concerning temperature and humidity control?

What do you think?

 

[JointOperation]

exactly what your thinking bro.. if your environment is stable.. it shouldn't kick on that much.. I had to partner with 2 people to complete an indoor during the outdoor season right.. and I didn't have enough cooling for the second room.. so we just put 2 exhaust fans and a very big passive intake bringing air straight from outside..

both rooms did great.. and the hotter room.. didn't do nearly as bad as I thought it would.. I mean.. there a tiny tiny bit less dense.. butttt the yield on the hotter room.. overshot the yield in the AC room..

ill guess that the EXTRA CO2 from bringing in tons of new air higher CO2 means higher temps can be held without issue.. and I think that helped more then the AC in the other room?

 

[HendrikOl]

exactly what your thinking bro.. if your environment is stable.. it shouldn't kick on that much.. I had to partner with 2 people to complete an indoor during the outdoor season right.. and I didn't have enough cooling for the second room.. so we just put 2 exhaust fans and a very big passive intake bringing air straight from outside..

both rooms did great.. and the hotter room.. didn't do nearly as bad as I thought it would.. I mean.. there a tiny tiny bit less dense.. butttt the yield on the hotter room.. overshot the yield in the AC room..

ill guess that the EXTRA CO2 from bringing in tons of new air higher CO2 means higher temps can be held without issue.. and I think that helped more then the AC in the other room?

The more Co2 you have the higher the ambient temperature can be (up to 28° C if I remember correctly).

So if I understand correctly your other room only had an AC without CO2?

However I would like to compare a sealed room with AC, Co2 and air cooled hoods vs an non-sealed room with air cooled hoods.

What I am interested if the sealed room will yield more due to the Co2 compared to a non-sealed room which for example has one more light, so both rooms consume the same total amount of energy (kwh).

 

[Granger2]

The most important factor in all this is humidity. Unless your humidity is generally always low, a non sealed room may be yielding just fine until you get Powdery Mildew and/or Botritus [Bud Rot]. Then you've screwed the pooch.

So I would say that a sealed room with AC, dehumidifier, CO2 is the way to go. If your usual temps, due to climate, are low, the AC won't run much, and the most important factor to success will have been achieved- a healthy room and environment. Good luck. -granger

 

[the gnome]

as for the op's Q of how often the ac will Kick on in the sealed room
it's going to vary on things like.....

how well insulated your room is,

how many watts are you going to run?

how efficient is your AC? a 24seer will cost less than a 14seer to run.
if it's a mini split get one with inverter comp. technology, you'll save there.

and yes, air cooled lights will save a good bit on your ac as opposed to running bare bulb.

using mag ballasts? run them outside the room, they run around 165F as opposed to my nanolux digi's @95F

of course you live in an environment that's on the cool side
and that can be utilized to your benefit going selaled or unsealed.
all that cold air could be a valuable asset cooling the room unsealed or the hoods sealed


Ive been running sealed since the beginning of the year now
and wouldn't do it any other way now.
AND
having complete control over your environment gives ya a slight God complex

 

[EclipseFour20]

I experienced about 5 degree drop when I did two things--brought in outside air into the closed environment (free CO2 at 300-600 ppm) and cooled my hoods with outside air...but that was with 3 lamps in a series/row. The first lamp always got cool air but by the time the air got to the 3rd lamp, it was warm/hot. So this past summer I "reducted" the lamps such that each lamp receives cool air directly from the outside. I picked up another 5 degree drop. Then I jacked up the fans from 6" to 8" and picked up about 3 degree drop....for a total decrease of 13 degree Fahrenheit.

Not saying you will get the same 13 degree reduction, as I am less than 10 miles from the ocean and it can get warm during the evenings in So Cali. But come December when the outside evening temp is 30-40 degrees--I experienced condensation on my "outdoor air" flex ducting inside the environment. Lesson learned: Use "insulated flex ducting" for all interior runs for "outdoor air". Kinda cool opening up the environment in December with the AC of "off"...cuz the temp is 74 degrees (all from outside air). Don't talk to me about July when night time lows are 70 degrees...LOL!

 

[JointOperation]

just becareful cooling with cold air threw your tubes.. condensation builds up and causes some very fun issues..

like don't bring in.. winter air into a 100 degree hood.

 

[5th]

just becareful cooling with cold air threw your tubes.. condensation builds up and causes some very fun issues..

like don't bring in.. winter air into a 100 degree hood.

That would only happen if the exhaust fan was either timed or set on a thermostat. (leaving the air in the closed loop for condensation to form)

As long as the fan kicks on when the lights come on ...your golden.

 

[EclipseFour20]

just becareful cooling with cold air threw your tubes.. condensation builds up and causes some very fun issues..

like don't bring in.. winter air into a 100 degree hood.

That is why insulated flex ducting is necessary to use inside the environment.

 

[ARTofMAKINGfire]

Even with insulated flex, you're can't insulate the glass on the reflector....

I've woken up (when I lived in spots) to water pooling up in cool tubes... not fun!

You have to think about thermodynamics...

 

[EclipseFour20]

Well I guess I am lucky or maybe--

-my light fixture hoods (no tubes here) behave differently than "tubes"...probably my hood do not get "cold enough" to generate condensation, or
-as my super duper fans (greater than 700 cfms) pulls the air...it also sucks out the moisture (no pooling)--remember I have 700-800+ cfm fans for every 3 lamps, or
-the temperature difference between my environment air and the outdoor air is not "extreme" as yours--I live in So Cali near the ocean, and frost is a "novelty" here (we have more days that exceed 100 degrees than we have nights that are 30 degrees or less)...or????

Now I do know this, if the "incoming" ducting (either rigid or flex) inside the environment was not insulated, you bet I got pooling of water (it dripped on the floor, on the plants, etc). But once I insulated all the "incoming" ducting--the exhaust side is not insulated, no more water--not even inside the lamp hoods. I would know--as there would be water streaks on the glass.

But these are my experiences....which may or may not be the same as yours.

 

[uho667]

I was running sealed growbox with co2 burner and only problems i had even dehuminditer couldnot take all water from air was work all day and night

So my bills where twice bigger then usualy so i prefer add more light then fight with hi humi

In a gas burning CO2 generator using propane, butane or natural gas, one pound of fuel produces approximately 3 pounds of carbon dioxide gas and about 1.5 pounds of water vapor. Approximately 22,000 BTUs of heat is also added. These figures can vary if other fuels are used.

CO2 GENERATORS
The CO2 generators we use for carbon dioxide enrichment are very efficient burners of propane or natural gas. By completely oxidizing the fuel, the generator gives off pure carbon dioxide - and lots of heat and water vapor! Growers planning to install C02 generators in their gardens should anticipate having to deal with excess heat and humidity from their new equipment. We approach this problem a number of ways. One method involves placing the generator in a remote location and moving the C02 through ducting to the air intake, where it is delivered to the crop by oscillating fans. A fan attached to the duct draws the C02-rich air from the generator, helping to dissipate heat and causing some of the water vapor to condense inside the duct. Sloping the duct slightly and placing a tray or bucket at the end to catch condensation run-offs helps in removing condensation from the duct. Another method is to suspend the generator overhead - above the garden - and use timers or control systems to supply C02 for brief periods during the light hours. All fans are shut off, the C02 generator goes on, carbon dioxide drifts downward onto the garden, and when the generator shuts off (by a timer or thermostat) the fans are turned back on to cool the garden.
The disadvantages of this method are:

periods of high temperatures in the garden - with no air movement
limited amount of CO2 supplied to the garden
excess humidity levels in garden
heat builds up rapidly from even a small generator.
High temperatures inhibit CO2 uptake by the plants, since heat stress can cause breathing pores on the leaves to close, blocking out carbon dioxide and interfering with photosynthesis. Because excess heat can be so harmful, generators usually cannot be used for more than a few minutes at a time, limiting the total CO2 supplied to the crops.
High humidity levels raise even higher at 'lights out', when temperatures in the garden fall. Excessive humidity levels in the garden during the dark period create real dangers of disease problems for the garden.
There are questions as to how effective the 'trickle-down' method of applying CO2 really is. The breathing pores on the leaves are located on the underside; CO2 hitting the top surface of the leaves cannot enter the plant through the thick protective wax coating on the leaves' upper skin. If CO2 (which is twice as heavy as air) pools around the roots of the crop, it can interfere with root gas exchange (oxygen into roots; CO2 and waste gases out) and affect the growth and health of the plants. If you can't use a remote location for your CO2 generators, and you have to keep your generator in the grow room, here are some tips for effective use:
Add fans to help cool garden quickly after generator shuts off, and to drive CO2 through the crops. An extra oscillating fan (or two) and a larger exhaust fan with bigger duct diameter will help!
Add control systems to co-ordinate fans and generator. Very precise control systems can turn fans off and on when generator starts and stops; they can supply brief pulses of CO2 frequently during the light cycle.
Shut off generator two hours before lamps go off, and run oscillating and exhaust fans right through dark period to eliminate left over carbon dioxide.
Generators work best in:

very large gardens with excellent air movement ability
grow-rooms or greenhouses with high ceilings

 

[EclipseFour20]

I hear you!

I did the math and compared CO2 generator vs tank...and tank won for me.

The capital cost for: CO2 generator, additional AC & humidifier was rather large (and very little "salvage" or resell value)--then after I estimated the cost for gas and additional electricity to run said appliances...I decided paying $10 to refill my CO2 tank was the wiser/simpler choice. One tank lasts me about 10-14 days, max.The last time I tested my CO2 (with those testing tubes), it hovered between 1200 and 1500 ppm when the lights were on, and 600 or so when lights are off (the same as outside air).

I can live with the inconvenience of going to "the barrio" to buy my CO2...lol.

 

[ARTofMAKINGfire]

Elclipse - Just checked some pics. The supply duct carrying the FREEZING cold air that day was in fact not insulated. Sorry this grow was 5 years ago and there've been so many...

So that would have been your third suggestion, that my supply air was MUCH colder. (and ducts uninsulated)

Also I agree completely even for a large grow, bottled gas is the way to go.

They make very large bottles too...

 

[EclipseFour20]

I must have a "mile" of ducting to operate my 130 sqft flower environment built inside my 2 car garage (built a room within the garage)--the ducting runs up to the ceiling and into my attic where it exhausts, and I have 10 spots under the roof eave where I bring the air inside (that is 10 rigid duct running to 4 DIY filter boxes).

12 lamps (24 holes for in/out)
2 trunks for every 3 lamps (fresh air & exhaust)--a mixture of 6" & 8" ducting
4 fresh air supply (constantly on) to the environment
1 exhaust (timed with electric damper) with fresh air turnover of 4-5 times

...and ducting exits to the attic (where a bank of 5 fans pull all the air).

Of course I have a scrubber setup (CAN 150 filter setup with a 14" fan that pulls 1823 cfms) that keep the odor to zero.

You know, if the outside air it too cold...you can always "warm it up"--I am thinking a simple thermostat and coil type heater would do the trick. Just thinking though....shame to have all that cold "free" air and not be able to use it.

 

[JointOperation]

grab 2 Ys have 1 for exhaust air.. keep half the air moving outside.. do the same with the intake.. except backwards.. so u have your exhaust and intake.. going into the Y .. and then back into your room.

u could also do lung room.

 

[ARTofMAKINGfire]

Eclipse - sounds like you got your HVAC on lock. One of the many vital components of a dialed in room...
I'm thinking of getting a 100lb tank VS a generator. Fill it once and I'm good.

 

[EclipseFour20]

Art,
It takes time/patience and lots of tweaking to get maximum coolness with minimum dollars. Just everytime I do the CO2 generator calculation--and compare it to $10 for a 20 lb tank, it does not make sense. Besides, if I go there on Saturdays, no cash required--just $10 worth of flowers per tank.

 

[ARTofMAKINGfire]

Besides, if I go there on Saturdays, no cash required--just $10 worth of flowers per tank.

Can't beat that.

What are you thoughts on this unit?

It can be ducted outside the room to remove all heat produced by a dehumidifier... They make 240V versions for efficiency/amperage drop.

http://www.zoro.com/i/G4475737/?utm...hopping_Feed&gclid=COHK1tGmwcECFWcF7AodsU0ADA

 

[EclipseFour20]

Don't kick me to the curb...but my flower humidity ranges normally between 40-50%...on rainy days it spikes to....(drum roll) 55%. So I don't have a dehumidifier in my flower.

In my veg, it ranges between 45-65% so I am more inclined to add moisture in that room. I guess, being in So Cali, living near the ocean, bringing outside air to cool the room and lamp hoods, not hydro, etc....is why my humidity is what it is.

Even on days with Santa Ana winds (zero humidity outside) the flower environment never drop below 45%. Guess I am lucky/blessed/paid my dues.

Sorry I could not be of help!