Cool tubes - can I use one with no fan?

guy incognito

guy incognito

Well-Known Member
I recently started getting my final set up going. I have 2 tents, 1 with 1000 watt MH and 1 with 1000 watt hps. The intake is the attic on one side of the house, and the exhaust is the attic on the other side of the house. The room remains cold in winter anyway, so im sucking cold outside air over the tubes and keeping them ice cold. I want a fan controller to regulate the speed and thus temperature, but given that it's so cold I have a few questions.

What if I didnt want to exhaust any heat? Could I just leave the fan off? Would the cool tubes and bulbs be fine so long as my room temp stayed down? Or should I just disconnect the intake and exhaust and leave the fan running by just recirculating the room air? What if I set the fan on a temperature controller and it stays off totally letting the temp build to it's set point, then when it gets warm the fan kicks on sucking ice cold outside air over the bulbs? Would this sudden temperature change shock the bulbs or the cool tube?
 
guy incognito

guy incognito

Well-Known Member
This is a permanent set up on the second level of the house. I will not buy more hoods, and switch them multiple times per year depending on temperature. I will need every bit of the 745 cfm pulling outside air to cool these tubes in the summer. I will need an air conditioner at that point also as the best I will be able to do when the ambient temp is above 90* is remove ALL heat from the tubes and still have a 90*+ room that will need air conditioning. I also don't want to mess with running ducting in and out of the tents as I switch hoods.

I have a feeling that just not running the fan is a bad idea. I think I should just disconnect the ducts and recirculate room air over it and plug the ducts to the attic until the ambient temp gets too hot. This solution will take about 5 minutes to implement. If however I get too much heat build up even in the winter with this then I will want to hook the ducts back to the attic and just reduce airflow enough to keep my temps at the correct level.
 
jondamon

jondamon

Well-Known Member
Just get yourself some VARIAC SPEED CONTROLLERS they are the ones that remove the buzz from slowing down the fans.

Then you can just mount the dial in your room or just outside and wind it up in the summer and wind it down in the winter allowing the air to not rush too quickly over the cooltube thus allowing the glass to heat up a little and increase room temps somewhat for you. If you keep a gauge at canopy level you can fine tune your temps just using your handy little dial on the wall.

This is what i would do. It would take as much time just to cut all the wires and get them connected to your fans as it would to remove the ducts and fans etc but with the controllers in place you could control it year round.


J
 
guy incognito

guy incognito

Well-Known Member
jondamon said:
Just get yourself some VARIAC SPEED CONTROLLERS they are the ones that remove the buzz from slowing down the fans.

Then you can just mount the dial in your room or just outside and wind it up in the summer and wind it down in the winter allowing the air to not rush too quickly over the cooltube thus allowing the glass to heat up a little and increase room temps somewhat for you. If you keep a gauge at canopy level you can fine tune your temps just using your handy little dial on the wall.

This is what i would do. It would take as much time just to cut all the wires and get them connected to your fans as it would to remove the ducts and fans etc but with the controllers in place you could control it year round.


J
Click to expand...
When I said remove the ducts I meant just pull them out of the hole on the wall and set it on the ground. Then air is still moving over the bulbs, but i'm not losing any heat to the outside. This room is basically disconnected from my central furnace so it gets the worst of all seasons. I am still testing this out, but with the fan running full force and only 1 light running the temps in the room were 55* today. I assume more lights will add more heat, but i'm afraid maybe i'm pushing too much into the attic. Maybe slowing the fan down will remedy this. I'm going to pull the ducts out of the holes and see how warm the room gets before I make a decision.
 
M

mrmadcow

Well-Known Member
I would expect the cooltubes to overheat without any fan. removing the ducting could work and/or maybe using a small PC fan in winter & swapping back in spring?
 
jondamon

jondamon

Well-Known Member
would you still be creating air exchange this way by removing the ducts?

old Co2 depleted air out
new Co2 rich air coming in

or would you be supplementing Co2 ?


J
 
guy incognito

guy incognito

Well-Known Member
There is currently no air exchange sytem. Cold air comes from one attic, cools the tubes, and is exhausted into the other attic - never co-mingling with grow room air. This is not a closed sealed environment. It's the upstairs bedroom in my house, so i'm assuming if there is enough passive air exchange for a human to breath there will be enough for plants to breath.
 
MrMoores

MrMoores

Well-Known Member
DONT turn on your bulb without an exhaust hooked up to the cooltube i did this with a 600w mh just to see it on for a minute [childish] and it cracked my cooltube in about 15, 20 seconds, i run a an almost identical setup to you, but i did nt hear u mention your fan that drags thru ur carbon can your gunna need one of these for each tent, i think ur fan will drag the rite amount of air thru to keep temps where u want them id just put the mh closest to where the air comes in, for comparison i have a fan that drags 600cfm about 1 meter away from an open window and then a Y junction inside my tent where it splits to 2 600w cooltubes then another Y on the other side to join them back up to one peice of ducting then about another meter of ducting and straight out in to the room, from there i have my tent closed always [unles watering or admiring] so my can sucks thru the open flaps at the bottom so im getting fresh warm air always, temps are around 80 or below wich isnt to bad considering i have 1200watts in a 1.2 by 1.2 tent, i am also keepin an eye on the problem u have... when lights are off it gets fuking cold i chek my max/min temps every morning and its down to 12c this moring, 42 or 46F i think,so u may need a small heater, i had an idea of buying a roofing vent for intake this would stop any re-curculation of air that u might get from having ur intake and exuast in the same space, just be aware of your electrical complication you need your can on 24/7 so it needs to be on a seperate feed from ur lights and ur cooltube fan otherwise your dragging freezing air in all day n night
 
guy incognito

guy incognito

Well-Known Member
MrMoores said:
DONT turn on your bulb without an exhaust hooked up to the cooltube i did this with a 600w mh just to see it on for a minute [childish] and it cracked my cooltube in about 15, 20 seconds, i run a an almost identical setup to you, but i did nt hear u mention your fan that drags thru ur carbon can your gunna need one of these for each tent, i think ur fan will drag the rite amount of air thru to keep temps where u want them id just put the mh closest to where the air comes in, for comparison i have a fan that drags 600cfm about 1 meter away from an open window and then a Y junction inside my tent where it splits to 2 600w cooltubes then another Y on the other side to join them back up to one peice of ducting then about another meter of ducting and straight out in to the room, from there i have my tent closed always [unles watering or admiring] so my can sucks thru the open flaps at the bottom so im getting fresh warm air always, temps are around 80 or below wich isnt to bad considering i have 1200watts in a 1.2 by 1.2 tent, i am also keepin an eye on the problem u have... when lights are off it gets fuking cold i chek my max/min temps every morning and its down to 12c this moring, 42 or 46F i think,so u may need a small heater, i had an idea of buying a roofing vent for intake this would stop any re-curculation of air that u might get from having ur intake and exuast in the same space, just be aware of your electrical complication you need your can on 24/7 so it needs to be on a seperate feed from ur lights and ur cooltube fan otherwise your dragging freezing air in all day n night
Click to expand...
I have a 6" centrifugal fan and carbon filter on the way from HTG supply. I'm going to set up a third tent and move my 400 watt hps up to this room as soon as it finishes with the current grow. I was considering getting another 1000 watt light and just keeping my 400 watt as a back up for when one of the 1000 watters croaks. It will be nice to have a constant working back up on hand in case something happens; I won't have to panic, especially if i'm busy with work or something. Anyway, i'm going to have all 3 tents in this room, and I will also be hanging/drying in this bedroom, so I am just going to scrub the air in the entire room with a single large filter.

I don't want to add supplemental heat because I know the heat from 1000 watt MH, 1000 watt HPS, and a 400 watt HPS will be more than enough to raise the temps in the room. I think I need to just get rid of less heat rather than adding it. My fan is currently running 24/7 because I havent set up a timer on it yet, but I doubt it's cooling the room that much. The air inside the cool tube is never in contact with the air inside the grow room. The only heat I lose while the lights are off is heat absorbed through the walls of the cool tube and ducting, because these are constantly at the outside temp with the fan running 24/7.
 
MrMoores

MrMoores

Well-Known Member
sounds good mate but things im wondering is the humidity it will defo be to high if u have the can on the outside of the 3 tents, and also the curculation of air you dont NEED to have the humidity spot on or to have air constantly exchanged but it will hinder your growth alot and puts time on as well iv noticed with my mates they end waiting like 5 months in hot humid stuffy grow areas, get an intake, if u have cavity walls just smash a hole in the wall and take it from the cavity, remember ur can will be dragging out smelly air but just as important its dragging out humid air so new dry air can come in
 
guy incognito

guy incognito

Well-Known Member
I think I will be fine during the winter. The humidity level in my house is gonna be like 20% for the next 3 months.

I was thinking of setting up the carbon filter with 4" ducting from each of the 3 tents to pull air from inside the tents. Not so much to keep the air outside the tents smell free (hopefully my entire upstairs will be odor free) but just to get some air circulation into the tents so they are entirely sealed off from the rest of the room.
 
jondamon

jondamon

Well-Known Member
guy incognito said:
so i'm assuming if there is enough passive air exchange for a human to breath there will be enough for plants to breath.
Click to expand...
we breath oxygen and plants use Co2 in the air.

if you have no airexchange then your plants cannot breath, you can breath but they cant.

for every tent you should have air exchange! each tent ideally should have its own filter and fan. That way each tent is then passively pulling ambient house air in. Without exhausting each tent you are just blowing around old Co2 depleted air that the plants cant use!


J
 
MrMoores

MrMoores

Well-Known Member
i agree totaly jondaman, if i was you incognito i would send both the air from my cootubes and the air that gets pulled thru your can in to your attic and let fresh air be pulled from ur house, couple of weeks ago i went to my mates house and put an air brick in for him, hammer and bolster, smash smash smash, bit of morter, easy shit

http://www.diy.com/diy/jsp/bq/nav.jsp?action=detail&fh_secondid=10657514&fh_view_size=10&fh_location=//catalog01/en_GB&fh_search=air++brick&fh_eds=ß&fh_refview=search&ts=1291157453692&isSearch=true
 
N

NLights420

Well-Known Member
old post but not is not true man. I run a 600 hps w/ cooltube with no fans at all (besides 2 fans in the room for plants). DOnt buy walmart glass and it wont crack. seriously tho ive had the temp at 105 before. never ever had a problem with the bulb blowing or glass cracking. BUNCH OF BULL! I do not think its necessary to have one i keep my tube 1" 1/2 away from my plants without any heat problems. Ive been doing this for years.
 
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