Inverter Type MiniSplit heating & air conditioning

Merkin Donor

Well-Known Member
I see one of the biggest benefits is being able to run multiple smaller heads in the room that allow you to deal with the humidity (latent heat) better. One big 36k head will just cruise along when the heat load is small, maintaining it's set point and not reducing relative humidity. Now you are running a dehumidifier to do the work that the hvac system should be doing. During lights out you could just run one 7k-12k head at full load (if the room is big enough) and let it handle both dehumidification and cooling.
 

Guess who

Member
Hi, & @ merkin & this is actually as per manufacturer advice on some models.
In the trade we use a manifold gauges between the vacuum pump & outdoor unit.
Otherwise there's no method of sealing the system & holding the negative pressure.
When taking the above mentioned manifold gauge lines off shredder valve an "acceptable amount of refrigerant (most likely R410a type) is lost" as outlined in koto protocol that usa championed & certainly follows

So my earlier advice of opening the liquid line first & allowing the refrigerant to purge a Small amount of vapour, the air is chased out first & the flare nut can quickly be sealed with one hand.

When taking my manifold gauges a a pipeline of 5M I'd allow -50grams of LIQUID refrigerant is lost when taking a manifold line of a fully charged system (probably 800/900 odd grams fully charged) and that's each time the engineer puts his manifolds on. I know guys who do it every 6 months as part of a manufacturer advised service/maintenance routeen ;) they do this to monitor pressures & record them as part of a detailed service package.

so It all depends on circumstances & if the system was expensive or not... Could have gotten it for a good price & all the "good practice" almost equals outlay on the whole system.
Us A/C engineers ain't cheep here in UK.
 

Guess who

Member
But I guess I'll leave the HVAC to the professionals.

Anyway hi guys :)

I'm here to do more listening, than talking.
Just thought my level 3 city & guilds in refrigeration & A/C may have came in handy on this topic ;)
 

Merkin Donor

Well-Known Member
Hi, & @ merkin & this is actually as per manufacturer advice on some models.
In the trade we use a manifold gauges between the vacuum pump & outdoor unit.
Otherwise there's no method of sealing the system & holding the negative pressure.
When taking the above mentioned manifold gauge lines off shredder valve an "acceptable amount of refrigerant (most likely R410a type) is lost" as outlined in koto protocol that usa championed & certainly follows

So my earlier advice of opening the liquid line first & allowing the refrigerant to purge a Small amount of vapour, the air is chased out first & the flare nut can quickly be sealed with one hand.

When taking my manifold gauges a a pipeline of 5M I'd allow -50grams of LIQUID refrigerant is lost when taking a manifold line of a fully charged system (probably 800/900 odd grams fully charged) and that's each time the engineer puts his manifolds on. I know guys who do it every 6 months as part of a manufacturer advised service/maintenance routeen ;) they do this to monitor pressures & record them as part of a detailed service package.

so It all depends on circumstances & if the system was expensive or not... Could have gotten it for a good price & all the "good practice" almost equals outlay on the whole system.
Us A/C engineers ain't cheep here in UK.
Can you show me a link to any manufacturer that allows any method other than pulling a vacuum to a specific point for installation purposes?
A valve core remover with a side port for the micron gauge, single hose (larger is better) and a vacuum pump is all that's needed to evacuate a system.
If you are using analog manifold gauges to pull down the system you won't know if there is a leak or if you've achieved the correct vacuum . Bubble testing at 150-200 PSI won't show a leak apparent at 550 PSI.
Anyone putting gauges on a system as a matter or routine maintenance is just screwing their customer and worse polluting the environment for no reason. Measured airflow, supply and return wet bulb temps along with testing static pressure (ducted systems) is all that's need to asses system performance. Anyone saying otherwise is full of shit and needs to go back and learn their trade from someone other than the guy who has been "doing it for twenty years" the wrong way.
 

Guess who

Member
Merkin I personally think you need to F-off under a bridge and troll elsewhere... Not the first time I've read you getting lemon with replies on here. Just a Banger!


Curious your experience & or expertise in the fridge game tho?????????
Or is it just Google quotes we're getting
:???:?????????????

& We're still talking about a grow room are we not??????????????
Nothing fancy, just Controlling a temperature in a grow room.
IMO there is no need to go buy a vacuum pump(not cheap in uk), refrigerant lines, torr gauge, valve core remover.
Clearly you never practiced in the A/C & fridge game.


And in my opinion it can be done by a non professional using a purge method.
Less than a few grams of vapour is lost (no harm) system doesn't have to last 15 years from a laboratory spec instillation.

My point is if the system didn't cost more than say... £500 which gets you a mitsubishi heavy industry 2.5kW, Fan coil & Condensing unit system
(copper pipes pipe are sourced separately & manually formed, sleeved & brazed together here)
But you can Get a 2.5kw misti no problem from a wholesalers eBay account

SO WHY SPEND another £300/£400
buying all the tools or invite a random workmen into your Intended grow space :) to Install a small split???
For the sake of 10 G's max lost refrigerant During purge I say.

BUT... why let that get in the way of a good yapping & quote Google session.

Too much time on your hands buddy. Peace out
 

Guess who

Member
Footnote*

Admittedly I don't practice the purge method professionally as the kit I'm dealing with is too expensive. But I have observed it on cheaper models I'll try remember their names for the orical aka merkin. I shall provide a link as well.

Horses for courses tho.

a £500 mitsubishi industries spilt, if you get 7/10 years out, you're laughing.
probably costs efficient to upgrade anyway by that time.

A non professional can wing it and get
7 to 10 with barely any refrigerant loss OR buying up a small business worth of tools ;)
 

Merkin Donor

Well-Known Member
Guess who, obviously one of those guys. On one hand "technicians" like you make me lots of money cleaning up your shitty work but on the other you give the industry a bad name.
Got to love the ignore button.
Now Piss off
 

Guess who

Member
Or perhaps... the dog licks your face, wakes you up. realise you've been dreaming all those "fixing bad engineering practices" AND you've Pished the bed.

time to get up, change the bed sheets, & be a keyboard warrior quoting Google??????

My scenario sounds the more likely reading what you've copy & pasted.
;)
 

Budley Doright

Well-Known Member
Or perhaps... the dog licks your face, wakes you up. realise you've been dreaming all those "fixing bad engineering practices" AND you've Pished the bed.

time to get up, change the bed sheets, & be a keyboard warrior quoting Google??????

My scenario sounds the more likely reading what you've copy & pasted.
;)
Actually Merkin speaks the truth. If you showed up at my door to do a install and had no micron gauge or pump you wouldn't be there long. As for purging ...... Ummm nope!!!! As for losing refrigerant because your line set is long .... Better get proper gauges!!! Just stop lol.
 

Budley Doright

Well-Known Member
W
Hello to all of the D.I.Y. Rocket Surgeons out there. I have read many a thread on this site where one guy says he wants to turbocharge his grow room AC system and he is pretty sure he knows what to do but just wants to bounce his idea off another
Stone head to get the okey doke , due diligence complete, time to proceed with confidence. If it burns the house down I can blame that guy confirmation.
If you burn your house to the ground with you in it, it's your fault , you are a dumb ass. A dead dumb ass.

Please don't start taking apart high voltage sophisticated microprocessor controlled , fuzzy logic talking , Oriental cooling device to "Improve it" . Don't take the advice of some stoner telling you to rip out this and put in a relay and bypass that thing and then it should work better Consultant.

Yes some people do know some things about air conditioners but There are very few that know enough to be giving free advice and telling you to modify the electrical control system.
Think about it , inside your house you have an appliance that uses high voltage, it's almost always running, sometimes there is water around it and in it. Lots of hours go by without anyone checking up on it. That's scary enough , add in the fact that some guy told you it's okay to rip out the electrical and add in this or that and put it all back together and put High voltage to it.
Now your system had been tweaked .
Who knows what could happen now?
I will tell you who knows, I know. That tweaked AC system is capable of burning down your house with you and your family in it.
Please don't give advice to people that could result in them burning to death.
Please don't take advice from people and act on it then burn while you sleep.

I have been in the hvac business for over 49 years. I know a great deal about mini split systems. I have never burned down anyone's house yet, by accident.

I would be happy to help any of you with questions you may have regarding any heating and cooling issues.
I am not trying to come up , I'm just trying to
Prevent forest fires.

I am a certified Expert on JustAnswer.com
I am NATE certified
I hold a E.P.A. Universal Refrigersnt license
I was a Refrigeration Contractor for 20 yrs
I am a private pilot,
And I enjoy getting toasted on my porch watching the clouds float by.

Post your AC questions here and I will answer them here .

I'm Jeff P. and I'm a pot smoker.

And don't burn the house down!
Whats a EPA universal refrigerant licence? Thinking it's the same as we have up here but called ODP certificate. I take the fucking course every 5 years cause I keep forgetting to renew it lol
 

bottletoke

Well-Known Member
W

Whats a EPA universal refrigerant licence? Thinking it's the same as we have up here but called ODP certificate. I take the fucking course every 5 years cause I keep forgetting to renew it lol
They still have the odp program? I took it 20 years ago when I was a transport reefer tech for thermoking, I was under the impression that it was temporary until they created those in between jobs (reefer mech) into actual trades.
 

Budley Doright

Well-Known Member
They still have the odp program? I took it 20 years ago when I was a transport reefer tech for thermoking, I was under the impression that it was temporary until they created those in between jobs (reefer mech) into actual trades.
Still got it and still need it lol. I had just passed my C of Q for ref. when I had to take it ....... Like fuck really lol. Took all of 10 min. And $150 :o
 

Budley Doright

Well-Known Member
But I guess I'll leave the HVAC to the professionals.

Anyway hi guys :)

I'm here to do more listening, than talking.
Just thought my level 3 city & guilds in refrigeration & A/C may have came in handy on this topic ;)
Not if your telling people how to do it wrong, and sadly you are :(.
 

Guess who

Member
Really???? So enlighten me then from your extensive knowledge other than the 10G's vapour loss what's the F-ing issue??????

We're talking about a grow room let's not get pretentious.
It's a grow room cheap A/C system
NOT me showing up at your house as professional. So that little statement is irrelevant straight of the bat.

But F.... It let's do it right for talking sake... So you'd recommend pressure testing as well then??????
Make that an Oxygen free nitro regulator(£200) & a bottle of nitrogen for another (£40) call it.

Ohhh dear, this buffalo bill gets bigger daily man!!!!
For the sake of 10 G's & a tiny chance of traces of non-condensibles in system...

Know what you're right mate!!! Drop a grand on cheap A/C system sounds a plan Stan.

You 2 schooling him... & there's a small business right there. Or I'd he better just buying shares in screwfix & be done with it. Probably suspect the tool list isn't finished yetdoing it by the book of course.
 

Guess who

Member
Or as your man merkin said earlier the suave digital manifolds are an option at (£400+vat)
& they'll show possitive & negative pressures.
Still need that OfN regulator tho (£180) proper pressure test remember.

Oh & a vacuum pump @ (£200)

Sterling advice lads.

Better off just inviting a random A/C guy into the grow room. Cheaper.
 

Big smo

Well-Known Member
i sat here for a minute and thought why the hell did I even read this thread. Oh mini split yeah I got one. The drama seems to be the entertaining part though. I was gonna install mine myself also but Amazon was out of thermal reactor conductor gauges. I hired a pro. Then got fucked. Leaking all sorts of shit down the lines. He then told me he was coming back to smash my walk out and said if it was a nail that I sent through it to cause the leak he was charging me a 500$ service call. The cock didn't tighten the nut up enough. Another patch, paint and 4 hours of my life I'll never get back.

Reason for posting this is you guys seem to know your stuff. He said he checked the refrigerant level but I know he didn't. Should I call someone else to make sure? Will it hurt the system?
 

Merkin Donor

Well-Known Member
i sat here for a minute and thought why the hell did I even read this thread. Oh mini split yeah I got one. The drama seems to be the entertaining part though. I was gonna install mine myself also but Amazon was out of thermal reactor conductor gauges. I hired a pro. Then got fucked. Leaking all sorts of shit down the lines. He then told me he was coming back to smash my walk out and said if it was a nail that I sent through it to cause the leak he was charging me a 500$ service call. The cock didn't tighten the nut up enough. Another patch, paint and 4 hours of my life I'll never get back.

Reason for posting this is you guys seem to know your stuff. He said he checked the refrigerant level but I know he didn't. Should I call someone else to make sure? Will it hurt the system?
The only way to check for correct charge is to pull it out and weight it. Do you have a digital thermometer? If so and you can run it in heating mode with out damage to plants, see what the supply air temp is and will the fan go to high. If you can get high fan speed and a temp over 110 you are probably fine.
 
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