HVAC experience? / AC questions

Nizza

Well-Known Member
I remember finding that page because I remember seeing the 17.1 min. breaker size and laughing. I think I have a few 17.3A breakers kicking around, but no 17.1A at the moment...jokes.

But yea, these numbers still left me guessing:
Max Breaker Size20
Min. Breaker Size17.1
Amperage Requirement20
So the thing requires 20A (max? avg?), but that's also the "max" breaker size they advise? ..Huh?


And the "min" breaker size is... 17.1A, say what?
The "Amperage Requirement" says 20A (again; max? avg?) If that's the case I would immediately think it needs 10awg wire, because it'd be at the literal limit of 12awg (and well beyond the 16A at 80%), but then the appropriate size breaker for the 10awg wire would be 30A.

I duno if this is just the way hvac equip/industry/trade specs or "labels" stuff - I don't think it is; at least that is - when I see the actual information sticker on the unit it gives specs that make fucking sense to me, haha. Like any other specs sticker on any other electrical device.

"Spec sticker"? What the fuck is the name of that area on a piece of electrical equipment? 'Something' plate?
just go by the max circuit breaker size to be safe. I see what you are saying amperage requirement but max breaker size is what we go.

in the trades we usually call it a name plate but I'm sure there's a different name for it
 

2com

Well-Known Member
just go by the max circuit breaker size to be safe. I see what you are saying amperage requirement but max breaker size is what we go.

in the trades we usually call it a name plate but I'm sure there's a different name for it
Name plate, that's what I was lookin' for.
Thanks.
 
it's only 6 amps on a 240 cause it's 6 amps per hot line.

As long as the breaker is installed to keep the wire safe and the breaker is above the min amount it should be fine.

But I also would rather just run 50amp 240 6 gague everywhere than have to MAYBE come back and upgrade
 

Nizza

Well-Known Member
Name plate, that's what I was lookin' for.
Thanks.
anytime dude. any questions involving wiring let me know. I don't do the electrical but I'm HVAC so i have a rough understanding of things. You will also need to run a communication wire when you run the line sets and drain just so you're aware. It is a wire that carries power from the condensor to the mini split head. Some units are a little different I only install fujitsu and mitsubishi
 

kovidkough

Well-Known Member
Yea, that part is all good. The general conventions (and approximate/actual limits by code etc) and such.
What I'm saying, is the AC (or ACs) in question do not draw 30A, so they don't need 10awg wire. They don't draw 24A either, from what I'm kinda hearing is they might draw around 12A give or take and that is max.

If the ACs only draw a maximum of, for example 15A, then 12awg wire should be fine as it's good for up to 20A ("20a is 12g", conventionally), and even at 80% of 20A (rated for "continuous loads") it'd still be under the 16A limit by 1A.

Btw, did any of your buddy's here start calling you rickymartinman? I was hoping it might stick. @kovidkough ?
living la Vida loca
 

getogrow

Well-Known Member
I remember finding that page because I remember seeing the 17.1 min. breaker size and laughing. I think I have a few 17.3A breakers kicking around, but no 17.1A at the moment...jokes.

But yea, these numbers still left me guessing:
Max Breaker Size20
Min. Breaker Size17.1
Amperage Requirement20
So the thing requires 20A (max? avg?), but that's also the "max" breaker size they advise? ..Huh?

And the "min" breaker size is... 17.1A, say what?
The "Amperage Requirement" says 20A (again; max? avg?) If that's the case I would immediately think it needs 10awg wire, because it'd be at the literal limit of 12awg (and well beyond the 16A at 80%), but then the appropriate size breaker for the 10awg wire would be 30A.

I duno if this is just the way hvac equip/industry/trade specs or "labels" stuff - I don't think it is; at least that is - when I see the actual information sticker on the unit it gives specs that make fucking sense to me, haha. Like any other specs sticker on any other electrical device.

"Spec sticker"? What the fuck is the name of that area on a piece of electrical equipment? 'Something' plate?
Im thinking just like you ans saying maybe a 10 wire for this one but were overthinking it. The label says 20 amp max so thats what they expect you to install. im guessing 17.1 is the actual startup draw, then it probably goes down to about 12 ish.... Im sure it never goes over the 17.1 rating.
 

2com

Well-Known Member
You will also need to run a communication wire when you run the line sets and drain just so you're aware. It is a wire that carries power from the condensor to the mini split head. Some units are a little different I only install fujitsu and mitsubishi
I would've thought these acs come with all the product specific kit/parts in them, that's kinda fucked.
I'm don't mean the feed (power/source) from the panel, obviously that's not included. But any cables to connect/interconnect parts of the ac, I'm a little surprised that I'd need to go searching for some other cable for that. Lame.

I doubt the "diy" kits like mrcool are like that, they come with everything..I think.

I was gonna ask, is it your experience that most - almost all - of these ac, mini split or otherwise, only use two hots and a ground (ie: 10/2 would be fine)? Have you seen any/many that needed two hots, a neutral, and a ground (ie: 10/3)? If so, is it brand specific?
Thanks.
 

2com

Well-Known Member
Anyone else ever come across the "AC boxes made easy" thread on ICmag? There's a second thread where a user did a write of his build, having learned from the original thread. Can I link those here? If not, mod, just let me know and I/you can remove them.
Original thread, by HoosierDaddy: https://www.icmag.com/ic/showthread.php?t=95491
Another thread, by CannaBean: https://www.icmag.com/ic/showthread.php?t=194599

I didn't just come across these, I've known about it for almost as long as the threads have been around. I'm curious what your thoughts about doing this with a minisplit condenser are.
@Nizza? Any other hvac techs (or just those with experience, same thing).

I'm not curious if it'll "work", or "not work" - I know it'd work. I know how it can be done wrong, the thread has several examples of people who don't understand how they've done it wrong, etc.
Tiny house designs, and camping enthusiasts have done similar things and there are even some products that essentially work the same way. You could isolate the hot side, or the cold side, depending what you need.

I've done a similar thing with window ac, sorta...different application. I'd think a split system would only make it even easier to accomplish.

(Please, read/scan the original thread first before you post the problems you see or fear with this *idea*, because they've probably already been discussed. But by all means, please bring your experience or share any actual concerns one might have about it.)

Thank you.
 

Nizza

Well-Known Member
Ok so the window AC fan thing is doable but I wouldn't do that for a few reasons
- window a/c is already inefficient
- you are paying more using another fan to push the air out a duct to cool the condenser coil of the unit
-very unserviceable for maintenance
- need to do something with the condensate too, and a bunch of other weird crap

I have installed mitsubishi and fujitsu mini split heat pumps
- need condenser to be on a stand if used for heat in an area that you expect snow. If only for cooling you can get a cooling only model
- need to run a line set , drain, and communication/ power wire to and from the head and the condenser. this is a 4 wire (black terminal 1, white terminal 2, red {communication} terminal 3, and ground). It is good practice to use fork connectors for these especially the ground and red communication wire. You do not want to mix up the order of these. i can take a pic of the wire I use at work for you if you'd like
-condensers need 240v. this is 2 hots with 1 ground with whatever the max breaker size is with the appropriate wire and an electrical disconnect switch with the proper electrical fittings to the condenser.
- flare connections for the refrigerant piping and then nitrogen test at 400 psi, then after verified no leaks take a vacuum down to at least 500 microns, then shut off the manifold gauges and add gas if needed then open the valve ports


as for mr. cool, if it seems like something you'd like to try , try it out. but it will be nothing compared to an actually good minisplit brand as far as customer service and reliability goes. On the other hand if you can get the value out of the system I don't see why it is such a bad product, but me as an HVAC guy doesnt trust the "pre charged quick connect" line sets but at the same time if it works , it works!

happy to help any time man, I am happy to see ideas and put my input in that is a pretty cool window a/c tutorial
 

getogrow

Well-Known Member
I would've thought these acs come with all the product specific kit/parts in them, that's kinda fucked.
I'm don't mean the feed (power/source) from the panel, obviously that's not included. But any cables to connect/interconnect parts of the ac, I'm a little surprised that I'd need to go searching for some other cable for that. Lame.

I doubt the "diy" kits like mrcool are like that, they come with everything..I think.

I was gonna ask, is it your experience that most - almost all - of these ac, mini split or otherwise, only use two hots and a ground (ie: 10/2 would be fine)? Have you seen any/many that needed two hots, a neutral, and a ground (ie: 10/3)? If so, is it brand specific?
Thanks.
All of us have seen the same , i dont think any of us have seen anyhing other then 2 wire going to the units. hot,hot and ground. or black , white and ground. I highly doubt you will need a 3 wire for a mini split or anything of the sort.

When buying a mini split , remind me to stay away from the company thats not giving you all the stuff. You should get everything but the main power as you said.
 

2com

Well-Known Member
Ok so the window AC fan thing is doable but I wouldn't do that for a few reasons
- window a/c is already inefficient
- you are paying more using another fan to push the air out a duct to cool the condenser coil of the unit
-very unserviceable for maintenance
- need to do something with the condensate too, and a bunch of other weird crap

I have installed mitsubishi and fujitsu mini split heat pumps
- need condenser to be on a stand if used for heat in an area that you expect snow. If only for cooling you can get a cooling only model
- need to run a line set , drain, and communication/ power wire to and from the head and the condenser. this is a 4 wire (black terminal 1, white terminal 2, red {communication} terminal 3, and ground). It is good practice to use fork connectors for these especially the ground and red communication wire. You do not want to mix up the order of these. i can take a pic of the wire I use at work for you if you'd like
-condensers need 240v. this is 2 hots with 1 ground with whatever the max breaker size is with the appropriate wire and an electrical disconnect switch with the proper electrical fittings to the condenser.
- flare connections for the refrigerant piping and then nitrogen test at 400 psi, then after verified no leaks take a vacuum down to at least 500 microns, then shut off the manifold gauges and add gas if needed then open the valve ports


as for mr. cool, if it seems like something you'd like to try , try it out. but it will be nothing compared to an actually good minisplit brand as far as customer service and reliability goes. On the other hand if you can get the value out of the system I don't see why it is such a bad product, but me as an HVAC guy doesnt trust the "pre charged quick connect" line sets but at the same time if it works , it works!

happy to help any time man, I am happy to see ideas and put my input in that is a pretty cool window a/c tutorial
Yea, there's definitely some fuckery to plan for with building a box.
Yup, I remember pricing all the gear I'd need to install a proper (non-diy) split system, and I didn't wanna deal with it only because it can't be installed properly with the condenser on the outside of the building.

Window ac's are inefficient? Compared to what - split systems? They're definitely better than portable units, almost guaranteed, right..
This video helped shed some light, for me, on portables - I thought it was just dual exhaust is better than single exhaust, but apparently it's not that simple. There's a specific rating that dictates efficiency (I'm sure you know this, just saying out loud).

I just want something non portable, and with new inverter technology.

The condenser can't be outside, everything has to be inside for this build. Hence why I'm trying to think of AC boxes that would be easiest to build.

The "box" would be made of thick Rtek or similar "silverboard" rigid insulation, I think. Lightweight, insulating, easy to cut, place on ac and remove.

i don't wanna have to buy another portable...pieces of crap compared to "real" acs.

Edit: Another question. With the non-diy mini splits, if they're installed, can they be uninstalled and then moved and reinstalled? Is that something that is or can be done ever?
I also wonder if anyone's ever used a mini split and put the condenser in a "lung room" and used fan(s) to exhaust/supply fresh outside air to the condenser.
 
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kingromano

Well-Known Member
Yea, there's definitely some fucker to plan for with building a box.
Yup, I remember pricing all the gear I'd need to install a proper (non-diy) split system, and I didn't wanna deal with it only because it can't be installed properly with the condenser on the outside of the building.

Window ac's are inefficient? Compared to what - split systems? They're definitely better than portable units, almost guaranteed, right..
This video helped shed some light, for me, on portables - I thought it was just dual exhaust is better than single exhaust, but apparently it's not that simple. There's a specific rating that dictates efficiency (I'm sure you know this, just saying out loud).

I just want something non portable, and with new inverter technology.

The condenser can't be outside, everything has to be inside for this build. Hence why I'm trying to think of AC boxes that would be easiest to build.

The "box" would be made of thick Rtek or similar "silverboard" rigid insulation, I think. Lightweight, insulating, easy to cut, place on ac and remove.

i don't wanna have to buy another portable...pieces of crap compared to "real" acs.

Edit: Another question. With the non-diy mini splits, if they're installed, can they be uninstalled and then moved and reinstalled? Is that something that is or can be done ever?
I also wonder if anyone's ever used a mini split and put the condenser in a "lung room" and used fan(s) to exhaust/supply fresh outside air to the condenser.
yeah you need to bring back the coolin refrigerant inside the condenser(outdoor exchanger) of the unit before unscrewing the dudgeons connexions

you need some manifold with refrigerant hoses on it, a allen key (size 4 or 5 not sure) and ideally a vaccum pump to do it clean

and about putting outdoor units inside a room, yes you can do it
its very stealth
as long the air renewing is enough to allow good exchange between cooling refrigerant and air you're good
 

2com

Well-Known Member
1) Are the DIY minisplits generally more expensive because they don't require hvac tools etc., and if so, is the price difference/savings of buying a standard (non-diy) minisplit system enough to easily buy what hvac tools are needed (vac pump, fittings, etc.)?
-Wouldn't need to worry about buying refrigerant, and associated gear, and/or probably needing some fucking license to even buy it?

2) Having said required tools, would one be able to recharge vehicle ac systems, and maybe even fuck around with recharging window acs?

3) I might be able to talk myself into it if it's a considerable cost savings, and I'm able to get a solid design/plan worked out for cooling the condenser with an ac box and additional fan.
Would you help me check over the necessary tools, and make sure I have serviceable brands and not garbage, give me tips on additional supplies I'd need / or won't need? @Nizza
 

Nizza

Well-Known Member
1) Are the DIY minisplits generally more expensive because they don't require hvac tools etc., and if so, is the price difference/savings of buying a standard (non-diy) minisplit system enough to easily buy what hvac tools are needed (vac pump, fittings, etc.)?
-Wouldn't need to worry about buying refrigerant, and associated gear, and/or probably needing some fucking license to even buy it?

2) Having said required tools, would one be able to recharge vehicle ac systems, and maybe even fuck around with recharging window acs?

3) I might be able to talk myself into it if it's a considerable cost savings, and I'm able to get a solid design/plan worked out for cooling the condenser with an ac box and additional fan.
Would you help me check over the necessary tools, and make sure I have serviceable brands and not garbage, give me tips on additional supplies I'd need / or won't need? @Nizza
Definitely man I'll help you out. Id be glad to~ but tonight I have some stuff going on so how about tomorrow we go into the details of what you may need.
The mr. cool are much less expensive and come with all the stuff, but I just don't trust them (being someone with all the tools)
If you could get a good warranty maybe its worth it, the cost for a mr cool is around 1500 and the mitsu is around 2500 and youd have to get tools on top of that.

The problem is if the mr cool fails will the amount of problems it causes with the grow op be worth it? The mitsu could fail too, any unit can.
With mitsu or fuji you are paying for the tech support and better product but maybe you could save some money here

1) the diy mini's are less expensive, and may be worth it
2) yes, but you may need some more tools. Automotive uses a different fitting and to do window a/c work you would probably need to add an access port to test/fix a leak and recharge
3)It is also probably worth doing if it's cheap enough, why not give it a go if the savings are considerable enough. It would also save you the hassle of an electrician
 
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2com

Well-Known Member
Definitely man I'll help you out. Id be glad to~ but tonight I have some stuff going on so how about tomorrow we go into the details of what you may need.
The mr. cool are much less expensive and come with all the stuff, but I just don't trust them (being someone with all the tools)
If you could get a good warranty maybe its worth it, the cost for a mr cool is around 1500 and the mitsu is around 2500 and youd have to get tools on top of that.

The problem is if the mr cool fails will the amount of problems it causes with the grow op be worth it? The mitsu could fail too, any unit can.
With mitsu or fuji you are paying for the tech support and better product
Ok, sounds good. No rush, dude. At your convenience.
I may post some stuff, but don't take it as me "summoning" you, or anyone else. Hah. Just posting as I go.

I'm in canada. Check out the pricing on the mrcools DIY https://www.lowes.ca/dept/mrcool--room-air-conditioners-air-conditioners-fans-heating-cooling-a1176-fe2e8bd6976?display=24&filters=brand_s=MRCOOL
Lowes.ca is the only place in canada I've seen'em sold.
I thought they are more expensive than say, a non-diy kit. But I haven't been looking at mitsubishi or fujitsu, or anything top of the line.

Thanks.
 

kingromano

Well-Known Member
Ok, sounds good. No rush, dude. At your convenience.
I may post some stuff, but don't take it as me "summoning" you, or anyone else. Hah. Just posting as I go.

I'm in canada. Check out the pricing on the mrcools DIY https://www.lowes.ca/dept/mrcool--room-air-conditioners-air-conditioners-fans-heating-cooling-a1176-fe2e8bd6976?display=24&filters=brand_s=MRCOOL
Lowes.ca is the only place in canada I've seen'em sold.
I thought they are more expensive than say, a non-diy kit. But I haven't been looking at mitsubishi or fujitsu, or anything top of the line.

Thanks.
fujitsu is more mid line, still very good machine but a bit under mitsubishi
DIY splits are less expensive because they are lower quality and not reliable IMO for a serious grow op
about window ac, i think you can find some nice ones, i'm no connoisseur

i think connexions on vehicules are different, split systems use SAE connexion

about the "gas", it already comes inside the unit when you buy it (inside the condenser of the outdoor unit)
you just need to vaccum the unit after you installed it/verified your connexions are leakproof, and free the gas in the circuit

if it's installed in the rule of art the chances its fail are slim

if you live in europe the law F-gas are forcing you to have a licence to install it, and eventually even to buy it
but you can find some country who will be happy to sent the unit to you, and if youre handy you can install it (just don't tell you done it by yourself)
 

Nizza

Well-Known Member
I was looking at the window a/c things and what really are you trying to accomplish with the boxes why not just mount it through your grow wall?

also on the pictorial the unit is sideways~ a compressor going horizontal is a no-no!

I think it would help a lot to decide the a/c unit thing if you give a full run down of your setup
 

2com

Well-Known Member
I was looking at the window a/c things and what really are you trying to accomplish with the boxes why not just mount it through your grow wall?

also on the pictorial the unit is sideways~ a compressor going horizontal is a no-no!

I think it would help a lot to decide the a/c unit thing if you give a full run down of your setup
With the ac box, the idea is to avoid hanging the ac out the window. There aren't any usable adjacent walls to hang the whole unit through. So supply and exhaust air need to be ducted to/from the ac.

Which pictorial has the unit/compressor sideways? I know not to change the orientation of system/components.

I'm thinking that if making the ac box is necessary/priority, then I might be better off to get a window ac. No connections or tools needed (less money), less cost, and pretty easy to convert.
I don't know how many window/through wall units are available with inverter tech though.

What you need to know about setup/work in progress(hah)? Room size is 10x10x8ish standard room.
 

kingromano

Well-Known Member
With the ac box, the idea is to avoid hanging the ac out the window. There aren't any usable adjacent walls to hang the whole unit through. So supply and exhaust air need to be ducted to/from the ac.

Which pictorial has the unit/compressor sideways? I know not to change the orientation of system/components.

I'm thinking that if making the ac box is necessary/priority, then I might be better off to get a window ac. No connections or tools needed (less money), less cost, and pretty easy to convert.
I don't know how many window/through wall units are available with inverter tech though.

What you need to know about setup/work in progress(hah)? Room size is 10x10x8ish standard room.
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
 
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