HVAC experience? / AC questions

2

2com

Well-Known Member
kingromano said:
don't you have an empty room in plus of the flower room where you can put the outdoor unit ?
this way you can use a mini split
Click to expand...
You mean like a "lung room", another room next to the flower/grow room? There is a room adjacent, but as far as I know someone stays/lives in it.

So even if it were used, it'd need to have a large inline fan with environmental controls to keep that "lung room" live-able if there's someone in there. Not to mention the size, and noise - I assume, of the condensor...
 
kingromano

kingromano

Well-Known Member
yeah not really a lung room because you will not exchange air with this room ..both room will just communicate with the coppers lines of the AC

if there is someone in forget, the compressor/fan of the outdoor unit make noise
 
Nizza

Nizza

Well-Known Member
How about modifying a door to accept the window a/c unit instead of trying to build a big extraction box around the condenser part, and then the room that the condenser side is in do an exhaust fan to outside on a temp stat
 
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2

2com

Well-Known Member
Nizza said:
How about modifying a door to accept the window a/c unit instead of trying to build a big extraction box around the condenser part then the room that is in do an extraction fan
Click to expand...
Hmm..
Do you mean literally cut a hole through the door to the room and put the ac through that hole and mount it there, as if it were a window opening? My first thought is how funny/retarded that looks, haha. Then my second thought is the ac ripping the door off it's hinges from the weight.
 
kingromano

kingromano

Well-Known Member
building a box around the condenser and use an exhaust to refresh the air will not work
you will suck the air of the room at the same time and lose your co2
 
2

2com

Well-Known Member
Nizza said:
How about modifying a door to accept the window a/c unit instead of trying to build a big extraction box around the condenser part, and then the room that the condenser side is in do an exhaust fan to outside on a temp stat
Click to expand...
This is what "box material" will likely be. Insulating, light weight, easy to work with
https://s3.amazonaws.com/finehomebuilding.s3.tauntoncloud.com/app/uploads/2019/05/03130643/rigid-foam-insulation-types-700x817.jpg

kingromano said:
building a box around the condenser and use an exhaust to refresh the air will not work
you will suck the air of the room at the same time and lose your co2
Click to expand...
First, the case is removed. Then, the already separated evap and condenser (or cold and hot) sides are furhter (completely) separated, by using rigid foam insulation board pieces and spray foam insulation, etc.
Now, both sides are separated.
The hot side is given both a supply duct (from outside) and an exhaust duct (to outside). It's a sealed loop. It won't draw co2 from the room.

You need to read the first thread I posted, from icmag.
 
2

2com

Well-Known Member
Onextremebuzz said:
Call an electrician. You need 4 wire two hots a ground and a neutral. 240 volt single phase
Click to expand...
What exactly are you trying to reply to? When I asked about 3 wire or 4 wire (including ground) I was specifically asking about the 240V feed from the panel (from the panel, to the condenser/outside unit), and whether most of these 240V acs needed just the two hots and a ground, or if they needed the neutral as well (for some other, 120V function).

The answer is that most (if not all) of them do not need a neutral. I don't need to call an electrician. I did check with an hvac technician though, because that's what the question was pertaining to. All they said was "you don't need a neutral".

Maybe, you're confused and thinking that I was asking about the cable that connects the indoor and outdoor unit (which from what I can see always uses 4 wires in this setup - 240V. Usually "1, 2, 3 and GND", which is L1, L2, Comm, and Ground. I think it's "Comm", basically).

Note where he shows and describes the feed two black wires (the two hot wires; L1, and L2) and a green wire (ground):

Again, in the following sections of another install video shows the communication cable connections, 4 wires. At the end, just before the next section where the feed (from the panel/disconnect) is connected, he mentions the 3 wires that that will require; L1, L2, and ground (two hots and a ground; in this case red, black and green). Once inside the disconnect, you'll see the that the feed from the panel to it is three wires - again, it's two hots and a ground (red, black and bare). No neutral.

Here's the "interconnection" or communications section (4 wire cable):

Here's the mention of the 3 feed wires; L1, L2, GND, just before that section begins:

Oh, here's one where the sparky says he ran a 10/3 (10/3 plus ground, ie: 4 wires in the cable), and he's talking about the feed. Oh, but wait, in the comments a "Kevin" asks "Couldn't see if you ran a neutral to the disconnect. Also wondering if your specific model of HP required the fused disconnect. I've heard best practice is to not use them." To which the sparky/channel replies "This mini did not require one, but I always pull one.", further explaining why he did:

One more, to be thorough or for anyone else who might come across. Clip starts where he explains (240V. L1, L2 are hot, plus a ground). Then he shows the feed/supply wired up at the 10:20 mark. You can see a shot inside the disconnect at 10:44. See the three wires coming in from the feed/panel to the disconnect? The black, white, and bare wires? That's two hots and a ground. They connect to the three wires leaving the disconnect and going to the condenser unit, which are red, black, and green. Two hots and a ground. They could be, pink, orange, and turquoise though, and it wouldn't matter.

The 120V units will have an L, an N, and a GND terminal. Line, Neutral, and Ground.

Maybe you're just getting your post count up. It doesn't sound like you're trying to help, or you know what you're saying. But maybe you misunderstood, or you're just being lazy. Which I'm guilty of at times, too.
 
kingromano

kingromano

Well-Known Member
2com said:
This is what "box material" will likely be. Insulating, light weight, easy to work with
https://s3.amazonaws.com/finehomebuilding.s3.tauntoncloud.com/app/uploads/2019/05/03130643/rigid-foam-insulation-types-700x817.jpg


First, the case is removed. Then, the already separated evap and condenser (or cold and hot) sides are furhter (completely) separated, by using rigid foam insulation board pieces and spray foam insulation, etc.
Now, both sides are separated.
The hot side is given both a supply duct (from outside) and an exhaust duct (to outside). It's a sealed loop. It won't draw co2 from the room.

You need to read the first thread I posted, from icmag.
Click to expand...
ok got it
 
Onextremebuzz

Onextremebuzz

Well-Known Member
2com said:
What exactly are you trying to reply to? When I asked about 3 wire or 4 wire (including ground) I was specifically asking about the 240V feed from the panel (from the panel, to the condenser/outside unit), and whether most of these 240V acs needed just the two hots and a ground, or if they needed the neutral as well (for some other, 120V function).

The answer is that most (if not all) of them do not need a neutral. I don't need to call an electrician. I did check with an hvac technician though, because that's what the question was pertaining to. All they said was "you don't need a neutral".

Maybe, you're confused and thinking that I was asking about the cable that connects the indoor and outdoor unit (which from what I can see always uses 4 wires in this setup - 240V. Usually "1, 2, 3 and GND", which is L1, L2, Comm, and Ground. I think it's "Comm", basically).

Note where he shows and describes the feed two black wires (the two hot wires; L1, and L2) and a green wire (ground):

Again, in the following sections of another install video shows the communication cable connections, 4 wires. At the end, just before the next section where the feed (from the panel/disconnect) is connected, he mentions the 3 wires that that will require; L1, L2, and ground (two hots and a ground; in this case red, black and green). Once inside the disconnect, you'll see the that the feed from the panel to it is three wires - again, it's two hots and a ground (red, black and bare). No neutral.

Here's the "interconnection" or communications section (4 wire cable):

Here's the mention of the 3 feed wires; L1, L2, GND, just before that section begins:

Oh, here's one where the sparky says he ran a 10/3 (10/3 plus ground, ie: 4 wires in the cable), and he's talking about the feed. Oh, but wait, in the comments a "Kevin" asks "Couldn't see if you ran a neutral to the disconnect. Also wondering if your specific model of HP required the fused disconnect. I've heard best practice is to not use them." To which the sparky/channel replies "This mini did not require one, but I always pull one.", further explaining why he did:

One more, to be thorough or for anyone else who might come across. Clip starts where he explains (240V. L1, L2 are hot, plus a ground). Then he shows the feed/supply wired up at the 10:20 mark. You can see a shot inside the disconnect at 10:44. See the three wires coming in from the feed/panel to the disconnect? The black, white, and bare wires? That's two hots and a ground. They connect to the three wires leaving the disconnect and going to the condenser unit, which are red, black, and green. Two hots and a ground. They could be, pink, orange, and turquoise though, and it wouldn't matter.

The 120V units will have an L, an N, and a GND terminal. Line, Neutral, and Ground.

Maybe you're just getting your post count up. It doesn't sound like you're trying to help, or you know what you're saying. But maybe you misunderstood, or you're just being lazy. Which I'm guilty of at times, too.
Click to expand...
I know how to wire I just though all new 240s had to be 4 wire to be code.
 
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Nizza

Nizza

Well-Known Member
2com said:
Hmm..
Do you mean literally cut a hole through the door to the room and put the ac through that hole and mount it there, as if it were a window opening? My first thought is how funny/retarded that looks, haha. Then my second thought is the ac ripping the door off it's hinges from the weight.
Click to expand...
I was thinking just upgrade the hinges and use a metal door , I get what the box does to separate the air but now you need extra fans and shit. I was just thinking of something more simple.

also wouldn't you only need to box out the supply side of the unit to pipe it into the room? I was asking kind of the idea of the layout you say its a 10x10 but I was wondering the real lay out because you may be able to get a different unit, like a full run down of the spot.

to install a mini split you'll need
line sets appropriate for the tonnage and brand you're using (guessing 1/2 x 1/4)
pipe cutters for copper
a flaring block
nitrogen w/ regulator
manifold gauges
vacuum pump
micron gauge (optional)
allen key and 2 wrenches to tighten connections and open charge
electrical (power to the condenser, then the power/comm wire to the head)
drainage for the head in a/c mode, drainage for the condenser if using in heat mode

always use the OEM flare nuts included with the units, in case the line sets come with them do not use those. If you have a torque wrench use that and torque to manufacturers specs. Also you can ream the pipe before flaring (careful to not get copper flakes into the pipes) and you can put a drop of POE oil where the flare nut seats. reaming and oiling are optional but can be recommended by the manufacturer.

always test the lines for a long time if you don't have a micrometer to ensure you have no leaks, give it a nice vacuum and you can even purge some nitrogen a few times for a triple evacuation if you'd like. If you do have a micron gauge be sure it goes at least below 500, I always try to go below 100 though.

watch some videos on how to do it, it's pretty easy and everything required to do it is in the installation booklet that comes with the unit and every step of doing it. some units are different and sometimes directions change year to year so be sure to go through the install book.

There are different types of units that may be more suitable for your application so that is why I'm wondering the full situation of where/how you plan to do everything
 
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Onextremebuzz

Onextremebuzz

Well-Known Member
That's a lot of work lol. How many lights are you running? Is there a better way to cool it? Are you overpowering the grow? What's the LxWxH of the room? What type of lighting? Are they air cooled if they are hps? That might fix the issue its self. Do you have a Strong enough blower. Squirrel cage fan on a pulley. (HVAC) shit. What are you using to keep the humidity in check? Are you using soil or DWC. So many things left out I Cant help yea. Most people put those units on the roof in a commercial setting. I say you probably don't need a unit that big if you get your other factors corrected. I use no ac at all. 1 SE hps 1000 watt air cooled I hold 24.5 with 2 12 volt fans. Humidity whatever I want. Mind you I'm not cooling my light with 12 volt pc fans just bringing air in and out. If your talking about a through the wall ac I'm assuming your growing in a room in a house. Please update us with everything about your grow including the wire distance from the box to the unit. Might have to use a lower awg if it's more than a certain distance. Please provide pictures and Happy Growing. That's a 5x5x6 tent I was referring to earlier in this post
 
2

2com

Well-Known Member
Replies in body below:

Nizza said:
I was thinking just upgrade the hinges and use a metal door , I get what the box does to separate the air but now you need extra fans and shit. I was just thinking of something more simple.

One inline fan to exhaust the heat, if needed, depending on design of the box/options for evacuating the air, sized using the cfm of the built in/internal fan of the ac as reference. One inline fan and some duct isn't much for cost or difficulty. Compared to a new door - a metal one, and "upgraded hinges" for said door. Then, cutting a window ac sized hole in the door and mounting an ac to the door, which needs to be opened and closed to get into the room. Not to mention the other side of the door, hah.

also wouldn't you only need to box out the supply side of the unit to pipe it into the room? I was asking kind of the idea of the layout you say its a 10x10 but I was wondering the real lay out because you may be able to get a different unit, like a full run down of the spot.

Not if the ac is in the room. Either way, or both, can be done. The hot and cold side both "need" a "loop", if you will. Both need supply air/in, and exhaust air/out. It just depends on where you can/do locate the actual ac unit. Know what I mean? The ac boxes thread I linked to shows this in the diagram/sketches.
As for the layout of the room. It's a 10x10x8 cube. It has one door and one window. The window can be used to intake and/or exhaust. One wall has an adjacent room where some air exchange could be done (two holes in it). It was used before, and is empty now during "upgrade" planning/work.

to install a mini split you'll need
line sets appropriate for the tonnage and brand you're using (guessing 1/2 x 1/4)
pipe cutters for copper
a flaring block
nitrogen w/ regulator
manifold gauges
vacuum pump
micron gauge (optional)
allen key and 2 wrenches to tighten connections and open charge
electrical (power to the condenser, then the power/comm wire to the head)
drainage for the head in a/c mode, drainage for the condenser if using in heat mode

The only tools I don't have are the ones that are specific to this job/hvac (vacuum pump, manifold gauges, eccentric flaring tool, etc.). One of the vids I linked is a comprehensive instruction on an install, with an overview of the tools/parts needed.

always use the OEM flare nuts included with the units, in case the line sets come with them do not use those. If you have a torque wrench use that and torque to manufacturers specs. Also you can ream the pipe before flaring (careful to not get copper flakes into the pipes) and you can put a drop of POE oil where the flare nut seats. reaming and oiling are optional but can be recommended by the manufacturer.

Ok, gotcha. Thanks for the tip on nuts. Yep, deburr, bit of nylog or oil on flare surface - not threads.

always test the lines for a long time if you don't have a micrometer to ensure you have no leaks, give it a nice vacuum and you can even purge some nitrogen a few times for a triple evacuation if you'd like. If you do have a micron gauge be sure it goes at least below 500, I always try to go below 100 though.

Oh, most instructionals I've seen the hold under 500 for say 20-30 mins. You go below 100?

watch some videos on how to do it, it's pretty easy and everything required to do it is in the installation booklet that comes with the unit and every step of doing it. some units are different and sometimes directions change year to year so be sure to go through the install book.

I have been, on and off, for while now, haha.

There are different types of units that may be more suitable for your application so that is why I'm wondering the full situation of where/how you plan to do everything
Click to expand...
 
Nizza

Nizza

Well-Known Member
I wouldn't nylog the flare nuts, just test with nitrogen and use a torque wrench~ the manufacturers nuts are designed to stay there when torqued proper. be sure when fastening down the nut that you properly flared and are pressing the flare square onto the flare fitting when tightening the nut down

also 2 tons of AC may be overkill. How much wattage are you running in that 10x10?

I still don't quite get what the deal is as far as moving the heat from the condenser side of the unit is
you want to vent that heat to the adjacent room or just out the window? I am wondering also what size is the window, and what size holes are you allowed to use for venting the heat from the condenser

your plan if doin a mini is put the condenser out on the other side of the wall vs putting the window ac vents into it?
 
2

2com

Well-Known Member
Onextremebuzz said:
That's a lot of work lol. How many lights are you running? Is there a better way to cool it? Are you overpowering the grow? What's the LxWxH of the room? What type of lighting? Are they air cooled if they are hps? That might fix the issue its self. Do you have a Strong enough blower. Squirrel cage fan on a pulley. (HVAC) shit. What are you using to keep the humidity in check? Are you using soil or DWC. So many things left out I Cant help yea. Most people put those units on the roof in a commercial setting. I say you probably don't need a unit that big if you get your other factors corrected. I use no ac at all. 1 SE hps 1000 watt air cooled I hold 24.5 with 2 12 volt fans. Humidity whatever I want. Mind you I'm not cooling my light with 12 volt pc fans just bringing air in and out. If your talking about a through the wall ac I'm assuming your growing in a room in a house. Please update us with everything about your grow including the wire distance from the box to the unit. Might have to use a lower awg if it's more than a certain distance. Please provide pictures and Happy Growing. That's a 5x5x6 tent I was referring to earlier in this post
Click to expand...
I'm providing what's needed to answer the question. Here is the original question(s) I posted:
2com said:
Hi,

I don't know exactly what make/model of AC I'll be picking up, so I'm wondering if I should just run 3 wire + ground, or 2 wire + ground? Some of these units use a neutral, right? Maybe it'd be best to run the 3 wire + ground, just in case, so it's there.

I'm thinking of/looking for 24000 BTU at most, 240V, Inverter (mini split or window/through wall design) and would also like to know, what sort of amperage these units *actually draw* - as I'm getting some mixed info that isn't adding up or making sense to me.
Click to expand...
Question one: Do these 240V acs need 3 wire, or 4 wire (do they need a neutral)? Answer: 3 wire; No neutral.
Question two: What sort of amp draw for a 24000 btu, inverter, split ac? Answer: Varying.

I appreciate you're trying to help. But what question are you even trying to answer? You're just bringing up a bunch of details that you don't need to know about. "Might have to use a lower awg if it's more than a certain distance." Yea, I know this... "Please update us with everything about your grow..."? ...What? Haha.

Things are "left out" on purpose because they're irrelevant to the original question, so as to try and avoid this. This isn't a "help me design and spec a grow room thread". That's been done already, though I don't feel totally confident with what I got from doing that. I know you're trying to help.
 
2

2com

Well-Known Member
Nizza said:
I wouldn't nylog the flare nuts, just test with nitrogen and use a torque wrench~ the manufacturers nuts are designed to stay there when torqued proper. be sure when fastening down the nut that you properly flared and are pressing the flare square onto the flare fitting when tightening the nut down

also 2 tons of AC may be overkill. How much wattage are you running in that 10x10?

I still don't quite get what the deal is as far as moving the heat from the condenser side of the unit is
you want to vent that heat to the adjacent room or just out the window? I am wondering also what size is the window, and what size holes are you allowed to use for venting the heat from the condenser

your plan if doin a mini is put the condenser out on the other side of the wall vs putting the window ac vents into it?
Click to expand...
Will pm you.
 
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