Keeping the temperature down?
- Thread starter AZ007
- Start date
- Thread starter
- #22
If your room is 72 that means you are not getting enough of the 72 deg air into the tent.
You said when you open the tent, everything is fine.
You don't need air speed (although that could work)... You need air volume. You need to get more air in and out.
If you need to, cut a hole and add a 10" low speed fan or something.
What I mean is to simulate the 'open' tent with more vents and fans.
If you have an issue with the plants getting too much air speed, get larger fans and set the speed lower. The plants just need to be moved around and air needs to flow. The plants don't need 100MPH wind storm!
I had the same problem with my clones. They were almost uprooted, I put the fans on the lowest settings.
Focus on volume of air, not speed.
You said when you open the tent, everything is fine.
You don't need air speed (although that could work)... You need air volume. You need to get more air in and out.
If you need to, cut a hole and add a 10" low speed fan or something.
What I mean is to simulate the 'open' tent with more vents and fans.
If you have an issue with the plants getting too much air speed, get larger fans and set the speed lower. The plants just need to be moved around and air needs to flow. The plants don't need 100MPH wind storm!
I had the same problem with my clones. They were almost uprooted, I put the fans on the lowest settings.
Focus on volume of air, not speed.
- Thread starter
- #24
So Karl, i made this stupid drawing on paint just to try to show you how my set up looks ok. So thats the ac unit, like i said always on keeping the room cool, n thats the tent on the right, the inline fan on top and the small fan on the bottom bringing air in. I started questioning myself, why cant i maintain the temp inside the tent, if the room outside is always cold and i have an air flow? So yea i did realize i must not be bringing in enough cold air obviously, but how to fix that? I was thinking replacing the small fan with a 6" fan just like the one i have on top, that fan blows wayy more air than the small, and also maybe running an air duct from the bottom fan (bottom right) running towards the top right of the room and then towards the middle of the room. What do u think? The room is deff colder in the middle, so maybe id be pullin in more cold air from there rather than in that tight corner away from ac. And when u said focus on volume of air not speed, the faster the air is going in and out of the tent the more air volume u have?
- Thread starter
- #25
Heres the updated drawing lol just to give u a better idea when i said replace the fan and run an air duct
Do u think id have a better air volume and colder air in the tent like that?
Do u think id have a better air volume and colder air in the tent like that?
jlt1202
New Member
if you get your ac unit hooked up to a duct and SEAL it with the room, then you are able to put BOTH fans as exhaust and have more fresh air coming in more offten, can set timer to turn one off so you can build temps/RH then on when you want to dump it outside of tent.
- Thread starter
- #27
Dump the small fan and make the intake as large as you can. If the 6" is an inline < 300cfm, get rid of that and get a 10" or keep the 6" and add a 10".
Get as much exhaust as you can.
Forget the ducting on the intake. Cool air is all over the room, don't worry about access to the cool air. Focus on getting the cool air inside the tent.
The keep is getting the hot air out, get the small fan out of the way, make the intake larger, add a 10" to the exhaust, forget the intake duct.
Get as much exhaust as you can.
Forget the ducting on the intake. Cool air is all over the room, don't worry about access to the cool air. Focus on getting the cool air inside the tent.
The keep is getting the hot air out, get the small fan out of the way, make the intake larger, add a 10" to the exhaust, forget the intake duct.
- Thread starter
- #29
I will do that, ill update it in a few days, now as far as the 10" fan i cant do that i have no room to put it right now, i have to stick with the 6" so i guess like u said ill just take the small fan out the way and get another 6", Now another thing, my ac thermostat claims that the room is at 72F, but earlier i had my thermostat that i keep under the lights close to the ac, almost next to it, and it was indicating 80F lol, so maybe my thermostat is inaccurate..whats a good one? are the old school tube thermostats good?
You should be able to tell 72 from 80 by just standing in the room. I'd get a few different ones. The tube ones can work fine, I have one that the tube can move because it's loose. I adjust it base on the other ones.
I use two digital ones and compare them.
One simple test is to put it in water. You know water freezes at 32, so see what it reads when the water freezes. If it's correct there, it should be correct at 80.
One of my digital ones can go into ice water because it has an exposed probe, the other one can't. If you get a few of them, you can set them side by side and compare.
I don't know how to do humidity. I have two of those. One says 50 and the other says 30. I trust the digital one, but no way to tell that I know of, so I don't worry too much about it.
I use two digital ones and compare them.
One simple test is to put it in water. You know water freezes at 32, so see what it reads when the water freezes. If it's correct there, it should be correct at 80.
One of my digital ones can go into ice water because it has an exposed probe, the other one can't. If you get a few of them, you can set them side by side and compare.
I don't know how to do humidity. I have two of those. One says 50 and the other says 30. I trust the digital one, but no way to tell that I know of, so I don't worry too much about it.
- Thread starter
- #31
Well guess what i just did, i put that thermostat in my refrigerators freezer, and it only went down to 14F, im guessing a home freezer should be at 5F the least no? But i will do what u suggested, get a couple diff ones and compare..
Just putting it in the freezer is not a valid test, you need to put it into a cup of water, let the water freeze. Right when if freezes it should be real close to 32. A freezer can be anything less than 32, I run my fridge (non-freezer side) near freezing. You should watch it as the water starts to freeze. Once it gets ice at the top of the cup, the temp should be very close to 32.
- Thread starter
- #33
So how do i do it i wait til the water starts to freeze then i let it sit out and check the temp? Because the temp goes below 32F way before the water starts to freeze..cause the gauge is sittin in the freezer.. u know what i mean?
Yea, ok. You can take a glass/cup of water, sit it in the freezer, keep checking it till it has a layer of ice in the top.
Break the layer of ice, put the gauge in there and watch the temp. It should go very close to 32.
If it's a waterproof type, you can just drop it in there.
It should only take 2 min or so to completely change to the temp of the water. My guess is that it'll be 32 to 35 because water take a while to change temp.
Remember, water expands when frozen, using a glass might make it crack if you leave it in too long.
Break the layer of ice, put the gauge in there and watch the temp. It should go very close to 32.
If it's a waterproof type, you can just drop it in there.
It should only take 2 min or so to completely change to the temp of the water. My guess is that it'll be 32 to 35 because water take a while to change temp.
Remember, water expands when frozen, using a glass might make it crack if you leave it in too long.
- Thread starter
- #35
ty i did do the test, water was frozen one top, think layer of ice, then i let it sit out for like 3 mins or so and the temp went up to 41F. so i guess is must be off by like 6 degrees maybe 7 or 8, but i do have another gauge coming so i can make more comparisons, but i am more relived to know that whenever my tent it indicating 88 degrees, it is probably really at 80-82
You don't have to use the freezer. Just make ie water. If it's mostly ice, the water will be 32F.
Cheap thermometers are horribly inaccurate. Karl's idea is a good one. Get several thermometers and read the temps all over the place. Put several thermometers in each spot, then use an average of their readings. That should be pretty accurate that way.
There is a pretty simple rule of thumb to start with. Hold your hand at the top of the plant. If it's too hot, ie you have to move your hand, it's too hot for the plants. The temps can vary a lot in just a couple inches around the lights. I was worried because my thermometer with the remote sensor was reading 90F where I had it hanging. By comparing it to other thermometers and moving them all over the room, I realized that thermometer read way high, and that my room was actually very good temp.
What are the temps outside there? So the AC is a window AC? I thought you meant the house had central AC.
Here is a way to think about what you're doing. Think of the room and the tent as separate energy systems. In the tent, you are inputing heat via the light and removing it via the fan. There is a rate of temp change. The larger volume of air, at a lower temperature, you move, the bigger Delta T. If the temps are too high, you gotta move more air and/or make the air coming in cooler. If opening the tent helps, you might just need to open up the intake further. You do NOT want to use the same fan you're using as exhaust as an intake fan. You want to maintain an negative pressure in the tent, so your intake needs to be just slightly less cfm than the exhaust. This is not referring to the fans, but the actual air moving. If you're using a carbon filter, your exhaust is not moving it's rated cfm. When you add in friction in the ducting, you might be getting half. Keep that in mind if you decide to put in a larger intake fan. I'd experiment with opening up the tent first. You may be able to intake enough air by simply opening up the intake more.
Now lets look at the room outside the tent. Here you have heat being input by the tent's exhaust and being removed by the AC. This makes your AC work harder than it needs to. It has to remove enough heat to compensate for not just the lights, but the normal rise of temps in the room, the fans, you, etc. You could make it's job much easier of you vent the tent outside. I would run a duct from your tent exhaust and have it exhaust next to the AC. That alone should make a HUGE difference. By reducing the load on the AC, it can make the room cooler. This means the intake air for the tent is cooler, making the tent cooler, making the exhaust cooler, making it easier on the AC, making the room cooler, etc.... Do you see where I'm going here?
I wouldn't worry about the accuracy of the AC's thermostat anyway. It's all relative. If you want the room to be 75F and you find the AC needs to be set to 70 to get it, then who cares? Just set it at 70F. Even if you bought another thermostat, there is no garuntee it will be calibrated any better. By measuring the temps yourself, you essentially calibrating the thermostat on your AC. You learn that 70F on the AC means 75F in the room. Make sense?
Cheap thermometers are horribly inaccurate. Karl's idea is a good one. Get several thermometers and read the temps all over the place. Put several thermometers in each spot, then use an average of their readings. That should be pretty accurate that way.
There is a pretty simple rule of thumb to start with. Hold your hand at the top of the plant. If it's too hot, ie you have to move your hand, it's too hot for the plants. The temps can vary a lot in just a couple inches around the lights. I was worried because my thermometer with the remote sensor was reading 90F where I had it hanging. By comparing it to other thermometers and moving them all over the room, I realized that thermometer read way high, and that my room was actually very good temp.
What are the temps outside there? So the AC is a window AC? I thought you meant the house had central AC.
Here is a way to think about what you're doing. Think of the room and the tent as separate energy systems. In the tent, you are inputing heat via the light and removing it via the fan. There is a rate of temp change. The larger volume of air, at a lower temperature, you move, the bigger Delta T. If the temps are too high, you gotta move more air and/or make the air coming in cooler. If opening the tent helps, you might just need to open up the intake further. You do NOT want to use the same fan you're using as exhaust as an intake fan. You want to maintain an negative pressure in the tent, so your intake needs to be just slightly less cfm than the exhaust. This is not referring to the fans, but the actual air moving. If you're using a carbon filter, your exhaust is not moving it's rated cfm. When you add in friction in the ducting, you might be getting half. Keep that in mind if you decide to put in a larger intake fan. I'd experiment with opening up the tent first. You may be able to intake enough air by simply opening up the intake more.
Now lets look at the room outside the tent. Here you have heat being input by the tent's exhaust and being removed by the AC. This makes your AC work harder than it needs to. It has to remove enough heat to compensate for not just the lights, but the normal rise of temps in the room, the fans, you, etc. You could make it's job much easier of you vent the tent outside. I would run a duct from your tent exhaust and have it exhaust next to the AC. That alone should make a HUGE difference. By reducing the load on the AC, it can make the room cooler. This means the intake air for the tent is cooler, making the tent cooler, making the exhaust cooler, making it easier on the AC, making the room cooler, etc.... Do you see where I'm going here?
I wouldn't worry about the accuracy of the AC's thermostat anyway. It's all relative. If you want the room to be 75F and you find the AC needs to be set to 70 to get it, then who cares? Just set it at 70F. Even if you bought another thermostat, there is no garuntee it will be calibrated any better. By measuring the temps yourself, you essentially calibrating the thermostat on your AC. You learn that 70F on the AC means 75F in the room. Make sense?
Some of the tube types use metal clamps to hold the tube. I have a tube type that is glued in place.
I can move the one that has metal clamps to adjust it.
If you want, you can put some tape on the side and write down the corrected / adjusted numbers. Or if it's cheap, throw it away.
I don't know, but I think if you adjust the numbers, it should be fine. In other words, the difference between 30 and 70 might be say 2" of travel. If that part is correct, you might be able to just right the correct number on the side of the gauge.
The other option is to maybe invest in a really good one. I've seen some 'weather stations' that can run some big $$, but to me that a waste.
Once you find the sweet spot, just stay there. Right now, I run my A/C full blast during lights on and low or fan only (depending on how hot it is outside) during lights off.
Either way, it still sounds like you have some temp issues, just not as bad as you thought. I'd get the second exhaust fan and see what happens.
I can move the one that has metal clamps to adjust it.
If you want, you can put some tape on the side and write down the corrected / adjusted numbers. Or if it's cheap, throw it away.
I don't know, but I think if you adjust the numbers, it should be fine. In other words, the difference between 30 and 70 might be say 2" of travel. If that part is correct, you might be able to just right the correct number on the side of the gauge.
The other option is to maybe invest in a really good one. I've seen some 'weather stations' that can run some big $$, but to me that a waste.
Once you find the sweet spot, just stay there. Right now, I run my A/C full blast during lights on and low or fan only (depending on how hot it is outside) during lights off.
Either way, it still sounds like you have some temp issues, just not as bad as you thought. I'd get the second exhaust fan and see what happens.
- Thread starter
- #38
Thx alot for the help, yes it a ac unit in the room, i have a diff thermometer gauge coming in soon, and i will try to do something about the exhaust, ill see if tomorrow i can do something about it and have it exaust out of the room, because now im just puttin all that hot air back in the room, i didnt think it was gonna have a major impact but i think it is.
If you were using the same gauge to determine the room temp, that would mean your room is not 72 but probably lower. It's not likely that the gauge would be close at 71 and way off at 80. They are usually off by the same ratio.
One other issue that wasn't talked about is CO2. The plants need CO2 to grow. If you are not exhausting to the outside, how is the room getting fresh air?
Many have said, you need to get completely fresh air every 5 to 10 min. That means everything in the tent has to be gone in 10 min and replaced with fresh air. If the air in the room is 'used' tent air, it's NOT FRESH.
You're plants need fresh air during the lights on cycle.
I wish those CO2 meters where cheaper, I'd love to check mine.
One other issue that wasn't talked about is CO2. The plants need CO2 to grow. If you are not exhausting to the outside, how is the room getting fresh air?
Many have said, you need to get completely fresh air every 5 to 10 min. That means everything in the tent has to be gone in 10 min and replaced with fresh air. If the air in the room is 'used' tent air, it's NOT FRESH.
You're plants need fresh air during the lights on cycle.
I wish those CO2 meters where cheaper, I'd love to check mine.
CO2 Meter - Low cost CO2, temperature and humidity - Monitor by CO2Meter
The same unit can be found cheaper from fleabay but you have to wait for shipping from China.
The same unit can be found cheaper from fleabay but you have to wait for shipping from China.
