85 degrees too hot?? + REP....

303, I'd like to apologize ,with a clarification. What Scyntra said made me sound (and feel) foolish. we all know that 78 is perf and 85+ is too hot. I guess I was trying to make you feel a little better about your situation.
"I think I'm just going to have to deal with the 84.4 it averages at" < that is what i figured and i was trying to make you more comfortable with that fact.
Its REALLY hard to keep a tent with an HPS in it cool. The BEST way is a cool tube. My tent runs an average of 10-15 degrees hotter than the room its in. Its the best i can do without a cool tube. If there's someone out there who can beat 10-15 differential without a cool tube I sure would like to know how they do it! +rep from us both!! lol I've got my old CFL settup ready to take the place of my HPS on those inevitable days when it gets WAY too hot. Peace.

I have always had my room run hot, and never had a problem (around 80 to 90) but if I could add A/C I would, some plants can take it some can't. There is no "right" temp for all strains, each one will have its "ideal" temp average. An Indica won't grow well in the south and a sativa won't grow well in the north, if you know your strain then try and produce the ideal outdoor climate for it, indoors. Indoor growing is about creating "ideal" conditions not "controled". If you never got sick then your body would have no reason to make blood cells to heal, same with the plants, if there is no wind then the branches will grow weak. Unless you have a pain in the ass strain then I don't think you'll even notice that extra heat.

I am having a similar issue, the temps use to be easily manageable at 70-75 now since summer and my house being made in the 50's the heat has risen to be anywhere in the 80-85. I have to leave the AC to the house on but I find this to be not energy efficient. One of my concerns is that I need to find a way to cool this room down, without spending to much energy. I noticed these

Sunpentown

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evaporative coolers. But would this be an option to use in a single room? I can't find much on the power it uses during the day.

itsgrowinglikeaweed I have to apologize to you. I did not mean to make you sound or feel foolish in anyway, I did not even say anything about your post. I was just trying to answer Siddhartha question about indoor/outdoor temp. difference... sry for any confusion..

Scyntra said:

itsgrowinglikeaweed I have to apologize to you. I did not mean to make you sound or feel foolish in anyway, I did not even say anything about your post. I was just trying to answer Siddhartha question about indoor/outdoor temp. difference... sry for any confusion..

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No need to apologize at all! No confusion. Its all good bro! TYVM

... has the openings you need if you use them right. I am able to maintain temperature in a 10' x 14' area with 3-1000watt HPS lights, and 2-4' 8 tube t-5 lights. The only way I can do this is by cooling those 1000watt furnaces and since this is a closed system, it doesn't need any expensive fan. I have a duct booster fan I bought for less than $30.00 at the big box stores, it is 6" not 4". The cfm is 250. It blows air from the outside through all three 1000 watt lights and out the other side of the room.
If you buy a cool tube and install it with a closed system, the rest of your air handling can be used properly.
If smell is a problem and you need to use the carbon scrubber then that is where you would need the better fan, commonly referred to as a CanFan, and that is just what it is a fan that it bigger than the inlet and outlet in a container which makes it look like you have reduced the size of the duct work.
Your can fan will probably be adequate if you air cool the light separetly. And your intake fan needs to be slightly smaller cfm than your exhaust, creating a slight negative pressure or if it is passive it will need to be twice as large as the duct work for your exhaust. Having it passive will also ruin your smell control.
And don't forget the oscillating fan, it not only strengthen the stem, the air movement across the stomata is how your plants get rid of waste material IF the relative humidity in the room is in the proper range.
All three of these air handling systems need to be in place for you to be able to control your seven basics, there are not any short cuts. VV

Excellent tips on cooling everyone,.. What I'd like to know, which wouldn't be entirely impossible for someone to answer if they have the space (two grow rooms/areas) is what sort of difference is there in yield, all other things being equal, between 90 degree high temps and 75 degrees. I wonder if anyone has run that experiment just to see. How much less will an indica yield if properly watered and everything else is optimal?

I spend a lot of effort to keep things cool and still have it a bit warm. When you consider the expense of extra fans, cool tubes, running AC,.. is it worth the effort to lower the temps by 15 degrees?

I have several thermometers in my grow, so I know that my exhaust temp (warmest air not in direct light, from the top of the cabinet) is usually around 78,.. the air around the soil (coolest air) is 70ish,.. and at the canopy right under a 400w hps, is 85 to 88. The air in the room around the cabinet is usually around 68. I have several CFL's to supplement and a cool tube on my hps. The CFL's put out a lot of heat which stays in the cabinet until exhausted. I can't really supplement CO2 cause of the exhaust.

Now what I want to know is how much different would the yield be if I let the canopy get to 95, and didn't exhaust air and did supplement CO2. I doubt anyone can answer that though, and if I had space I would definately run the experiment myself.

Trying to keep it cool is by far my biggest expense. If someone told me the yield would only be 10% less with the same quality,.. yet the buds would be more fluffy and stretched by 25%,.. I probably wouldn't keep spending the money on AC to keep my place under 68 and the extra exhaust. It's a little chilly in the rest of the place, even with the vents closed.

I grow with my temps around 85 and still get almost a 4 ounces a plant, humidity is low so the buds get thick and fat, of course I hope to get central A/C soon so the whole house will be cooler and hopefully the room.

I here everyone talking about cool tubes BUT i dont understand how they can help in these situations
IF you do not have AC then your ability to COOL the light through a cool tube is ONLY as cool as the air you are pulling right? SO yesterday its 88 degrees outside, pull that hot air through cool tube...are you really helping? my room was at 88 degrees yesterday...my AC in the house in NOT working. I have cool tube capability BUT i dont use it cause of my reasons above. My room was only 88 for less than 2hrs SO i am not so concerned right now BUT when its 80 @ night coming up this will be problematic.


Peace

sirbudmaster said:

I here everyone talking about cool tubes BUT i dont understand how they can help in these situations
IF you do not have AC then your ability to COOL the light through a cool tube is ONLY as cool as the air you are pulling right? SO yesterday its 88 degrees outside, pull that hot air through cool tube...are you really helping? my room was at 88 degrees yesterday...my AC in the house in NOT working. I have cool tube capability BUT i dont use it cause of my reasons above. My room was only 88 for less than 2hrs SO i am not so concerned right now BUT when its 80 @ night coming up this will be problematic.


Peace

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The room air may be 88 but the HPS is WAYYYYY hotter. Even if you pulled 100 degree air through a cool tube it will still cool the light significantly, and therefor reduce the temp under the light where your plants are.
If you have a cool tube... measure the temp 10 inches under your....(do you have a 400w or better HPS?), and then measure 10 inches under it with the cool tube. HUGE difference. the cool tube isn't cooling yourr 88 degree room air its cooling your (idk) 200+? degree light.

Also, even if you dont have any temperature problems at all, use of a cool tube will allow you to put the light much closer to your plants without burning them. Thats a another HUGE advantage right there!

itsgrowinglikeaweed said:

The room air may be 88 but the HPS is WAYYYYY hotter. Even if you pulled 100 degree air through a cool tube it will still cool the light significantly, and therefor reduce the temp under the light where your plants are.
If you have a cool tube... measure the temp 10 inches under your....(do you have a 400w or better HPS?), and then measure 10 inches under it with the cool tube. HUGE difference. the cool tube isn't cooling yourr 88 degree room air its cooling your (idk) 200+? degree light.

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yeah I got 400watt MH......it has cool tube capability...so IF i hook this up, do i then still need another source or fan in the cab to pull air out as well then?

Peace

Search google for "Stanley Blower Mod". It's a cheap ($35) and VERY effective blower fan that moves a huge amount of air (around 300CFM). I've got mine hooked up now and it works like charm. Of course, this won't affect your ambient temp, but could help keep things in check!

sirbudmaster said:

yeah I got 400watt MH......it has cool tube capability...so IF i hook this up, do i then still need another source or fan in the cab to pull air out as well then?

Peace

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Well your plants DO NEED fresh air, so yeah, another fan for regular air exchange is recommended. The cool tube cools the light, and something else cools and refreshes the "cab" or tent or whatever you have. Cool tubes also come in handy for co2 users. They can suck out the hot air from the light without sucking out all the co2.

itsgrowinglikeaweed said:

Well your plants DO NEED fresh air, so yeah, another fan for regular air exchange is recommended. The cool tube cools the light, and something else cools and refreshes the "cab" or tent or whatever you have. Cool tubes also come in handy for co2 users. They can suck out the hot air from the light without sucking out all the co2.

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You can use the same fan for cooltube and exhaust if you want. I have a 400w hps in a 30"x20"x70" with cooltube with a carbon scrubber that is 1 1/2ft long 6in inside diam and 8in outside diam. I use the stanley blower as mentioned above to pull through both of them and my cab stays at 77

smppro said:

You can use the same fan for cooltube and exhaust if you want. I have a 400w hps in a 30"x20"x70" with cooltube with a carbon scrubber that is 1 1/2ft long 6in inside diam and 8in outside diam. I use the stanley blower as mentioned above to pull through both of them and my cab stays at 77

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Hmmm? You got any pics of that setup? I dont quite follow you? It sounds like you are just carbon scubbing the air you cool your light with lol. I'm pretty high right now lol. It is a holiday....

the stanley blower fan is rated at 1280cfm on low, 1750cfm on med, and 2180 on high, mine is set to high and excanges the air about once a min in a 2x3x4 cab. walmart has them for 45 bucks and it was the best investment ive made so far.

itsgrowinglikeaweed said:

Hmmm? You got any pics of that setup? I dont quite follow you? It sounds like you are just carbon scubbing the air you cool your light with lol. I'm pretty high right now lol. It is a holiday....

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Thats it, air is drawn from the cab through the scrubber then through the cooltube then out the cab.sorry ive never posted a pic

Trunk5 said:

the stanley blower fan is rated at 1280cfm on low, 1750cfm on med, and 2180 on high, mine is set to high and excanges the air about once a min in a 2x3x4 cab. walmart has them for 45 bucks and it was the best investment ive made so far.

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Yeah thats if it is moving free air, once you hook up some resistance most people have said it is about 265cfm or compares to the 265 dayton blower, so it is great price regardless.

smppro said:

Thats it, air is drawn from the cab through the scrubber then through the cooltube then out the cab.sorry ive never posted a pic

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Ohh I gotcha.