Design Questions 1600 Square Foot Basement

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FET

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A negative air pressure is difficult to maintain like that. I've always seen it the other way around. You create a positive pressure and let it force the hot air out. My brother was an HVAC guy and that's how he 'splained it to me. It has something to do with preventing mold. I think he said a low pressure environment allows it to propagate faster.
I think thats why most people run these air cooled lights from outside to outside but that doesn't help me during weather extremes. The guy before me was pulling cool air from his first floor up to his lights on the second floor and directly outside. It was an out building so he didn't really care...had no secondary use for the building.
 
ComfortablyNumb

ComfortablyNumb

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I wish my brother was here, he could tell you right off which is the most efficient way to go. I just don't have that knowledge.
 
FET

FET

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I'm thinking that if I forget about the other tents for now this would be a better arrangement.
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Anthem

Anthem

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Definitely which is why I'm thinking about pulling the Houses AC cooled air from my basement and exhausting the heat out during summer. During the winter I would just heat my house with it. During the summer though I would be dumping a lot of cfm creating a negative pressure in the house. Does this have negative consequences? I feel like it must. HVAC is a pretty tricky thing design wise.
You can go to Hawthorne Gardening and use their heat calculator to find the heat load requirements for your equipment, probably get a lot better information there than here because few run something like you are looking to do. There is also so information in here about ground up grows from back in the day that would help as well. I seem to remember someone by the name Gettogrow that had some information that would be useful.
 
ComfortablyNumb

ComfortablyNumb

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I agree. Keep it simple for now. Build it temporary while you take your time to redesign it on paper.
 
FET

FET

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You can go to Hawthorne Gardening and use their heat calculator to find the heat load requirements for your equipment, probably get a lot better information there than here because few run something like you are looking to do. There is also so information in here about ground up grows from back in the day that would help as well. I seem to remember someone by the name Gettogrow that had some information that would be useful.
Which part is exceptional?
 
Anthem

Anthem

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A negative air pressure is difficult to maintain like that. I've always seen it the other way around. You create a positive pressure and let it force the hot air out. My brother was an HVAC guy and that's how he 'splained it to me. It has something to do with preventing mold. I think he said a low pressure environment allows it to propagate faster.
I believe something is missing here. With positive pressure you would be pushing air into other areas outside of the climate controlled area because of the positive pressure. Negative pressure is going to be sucking air into the climate controlled area. Much like an isolation room in a hospital, these are negative pressure so that no harmful pathogens from inside the room escape to outside the room.
 
ComfortablyNumb

ComfortablyNumb

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I believe something is missing here. With positive pressure you would be pushing air into other areas outside of the climate controlled area because of the positive pressure. Negative pressure is going to be sucking air into the climate controlled area. Much like an isolation room in a hospital, these are negative pressure so that no harmful pathogens from inside the room escape to outside the room.
Those hospital rooms are designed with special air seals for that. He wants the heat pushed out. Fill it with cooler air and the heat will be pushed out.
 
Anthem

Anthem

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Those hospital rooms are designed with special air seals for that. He wants the heat pushed out. Fill it with cooler air and the heat will be pushed out.
I build hospitals for a living. The systems are not sealed in the manner you are referencing. Negative Pressure means exactly what I explained above.
You do not understand negative and positive pressure. Pushing hot air out and getting cool air in has little to do with positive or negative pressure. Hence the reason for air balancing. You can be moving 300,000 CFMs thru a room with no pressure change, provided you have the ducting and equipment sized correctly. Positive Pressure means the air pressure inside of a controlled space is higher than that outside. Negative pressure means the air pressure outside of the controlled environment is at a high pressure than inside the door. Think of an extreme case of positive pressure as a tire under inflation. That is positive pressure.
 
FET

FET

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How many 10' x 20' or 8' x 16 grow tent setup do you see on this site?
I just got here so I couldn't tell you. Thats why I asked. I'm fairly sure of my heat/cooling requirements... just less so on the design of it.
Those hospital rooms are designed with special air seals for that. He wants the heat pushed out. Fill it with cooler air and the heat will be pushed out.
Just to be clear the air cooled tubes contain the lights... and its that air you are trying to dump instead of cool... the air in the room is what will be enriched with co2 and cooled with a mini split. Did I explain that right? Its two separate air spaces.
 
ComfortablyNumb

ComfortablyNumb

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I build hospitals for a living. The systems are not sealed in the manner you are referencing. Negative Pressure means exactly what I explained above.
You do not understand negative and positive pressure. Pushing hot air out and getting cool air in has little to do with positive or negative pressure. Hence the reason for air balancing. You can be moving 300,000 CFMs thru a room with no pressure change, provided you have the ducting and equipment sized correctly. Positive Pressure means the air pressure inside of a controlled space is higher than that outside. Negative pressure means the air pressure outside of the controlled environment is at a high pressure than inside the door. Think of an extreme case of positive pressure as a tire under inflation. That is positive pressure.
That's wonderful. I was only parroting what I have heard from my brother. As I said, he was an HVAC guy for some time.

I meant exactly that. A higher psi inside the tent than outside to push heat out. I'm sure you have walked into a store and the 'airlock' entrance has a positive pressure to push the heat back out to conserve the A/C inside the airlock.
 
Anthem

Anthem

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I just got here so I couldn't tell you. Thats why I asked. I'm fairly sure of my heat/cooling requirements... just less so on the design of it.

Just to be clear the air cooled tubes contain the lights... and its that air you are trying to dump instead of cool... the air in the room is what will be enriched with co2 and cooled with a mini split. Did I explain that right? Its two separate air spaces.
I have seen a couple of people on here with a 10' x 10' but like a couple. If you know your HVAC requirements what are you confused about on the design?
 
FET

FET

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I build hospitals for a living. The systems are not sealed in the manner you are referencing. Negative Pressure means exactly what I explained above.
You do not understand negative and positive pressure. Pushing hot air out and getting cool air in has little to do with positive or negative pressure. Hence the reason for air balancing. You can be moving 300,000 CFMs thru a room with no pressure change, provided you have the ducting and equipment sized correctly. Positive Pressure means the air pressure inside of a controlled space is higher than that outside. Negative pressure means the air pressure outside of the controlled environment is at a high pressure than inside the door. Think of an extreme case of positive pressure as a tire under inflation. That is positive pressure.
I've been hearing things about postive pressure grow rooms too. Can't wait to read about it.

I know I just picture the room either blown up like a ballon for postive pressure which would mean more air is entering the room at a faster rate than it can leave or escape via exhaust vs the room be sucked in for negative pressure which means there is more air leaving or escaping the room faster than it can be replaced by the intake
 
Anthem

Anthem

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That's wonderful. I was only parroting what I have heard from my brother. As I said, he was an HVAC guy for some time.

I meant exactly that. A higher psi inside the tent than outside to push heat out. I'm sure you have walked into a store and the 'airlock' entrance has a positive pressure to push the heat back out to conserve the A/C inside the airlock.
The fan you are referring to is for insects. If you create a positive pressure inside the tent 2 things are going to happen #1 you will push hot air out but the tent is for all matters sealed because we do not want to have light leaks and #2 you are also going to make it harder for the equipment to push cool air into the tent because of the positive pressure. Again you really do not understand what needs to happen. We want air exchanges not positive and negative pressures. Positive and negative pressures require additional AMPS to run oversized equipment to allow the CFM's to flow correctly. What he is looking for is a correctly sized intake and outlet for no pressure change. But CFM's to cool the grow space.
 
FET

FET

19
3
I have seen a couple of people on here with a 10' x 10' but like a couple. If you know your HVAC requirements what are you confused about on the design?
I understand my heat production and therefore my cooling requirements. Just the numbers. I do not understand my hvac requirements because that is all encompassing. The design of it is far more complex than just a heat/cool calculator. I'm sorry if the link is actually more than that. I will check it out.
 
Anthem

Anthem

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I've been hearing things about postive pressure grow rooms too. Can't wait to read about it.

I know I just picture the room either blown up like a ballon for postive pressure which would mean more air is entering the room at a faster rate than it can leave or escape via exhaust vs the room be sucked in for negative pressure which means there is more air leaving or escaping the room faster than it can be replaced by the intake
Yes it can and is done for insect control. It makes it harder for the insects to enter the grow space but this is on a professional level and takes engineering and well more money than it sounds like you would like to spend to achieve.
 
ComfortablyNumb

ComfortablyNumb

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The fan you are referring to is for insects. If you create a positive pressure inside the tent 2 things are going to happen #1 you will push hot air out but the tent is for all matters sealed because we do not want to have light leaks and #2 you are also going to make it harder for the equipment to push cool air into the tent because of the positive pressure. Again you really do not understand what needs to happen. We want air exchanges not positive and negative pressures. Positive and negative pressures require additional AMPS to run oversized equipment to allow the CFM's to flow correctly. What he is looking for is a correctly sized intake and outlet for no pressure change. But CFM's to cool the grow space.
I admitted I don't know. So I'm taking advantage of you by tossing out things I've seen and heard. The majority of my quite limited knowledge comes from my brother, an Ex-HVAC guy.

Now, this is the first I've heard something that starts to explain things. It never occurred to me that increasing the pressure would also make it harder to pump against. Very obvious when you mention it though. And as I processed that thought my ADD said squirrel by whispering "fluid dynamics". Ahhhhh......... And the mist begins to clear.
 
Anthem

Anthem

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I understand my heat production and therefore my cooling requirements. Just the numbers. I do not understand my hvac requirements because that is all encompassing. The design of it is far more complex than just a heat/cool calculator. I'm sorry if the link is actually more than that. I will check it out.
If you understand your heat product and therefore your cooling requirements you have the basics. BTU (British thermal units) converts to tons of AC as the following equation.
12,000 BTU's equals 1 ton of Air Conditioning. Being in a basement the heat lead generated by outside influences is going to be at a minimum. I would probably go with a factor of like 1.1. to 1.2. Meaning that if your total heat load is say 100,000 BTU's I would look at cooling for say 110,000 BTU's or 120,000 BTUs.
 
FET

FET

19
3
Yes it can and is done for insect control. It makes it harder for the insects to enter the grow space but this is on a professional level and takes engineering and well more money than it sounds like you would like to spend to achieve.
Money is not really the issue. For the right benefits I would take the extra steps. In regards to the HPS vs LED I have credible sources with proven results insisting on the value of HPS and since I already have them at a cost so low its basically nothing. I figure it would be smart to use it. I can also completely take their advice almost blindly if I'm running basically the same set up.
 
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