Help- Wall mount Mini-Split vs Ceiling mount Cassette Air Conditioner

I was browsing styles of Mini split AC's when I came across Cassette style recessed ceiling style. I have the overhead room to put one of these guys if it will do me better than the wall mount. Could someone give me some advice on size of AC? Would I be looking for a 30,000 btu Mr Slim or 2 haha? and if I would need more than one, should they both go on the same wall or opposing walls? Id say same but I tend to overlook things on occasion..

My room is 8 1/2' x 11 1/2' x (up to) 11' tall (Will be framing off the rest of the room above for a veg space). I plan on 4 Gavita 1000w DE with 2 (dimmed) 600w bare Ushio Super Spectacular Blue bla bla bulbs on Solis Tek ballasts (so long as my plants dont over grow the space I am giving them), ballasts in the room, 4-6 16" wall fans, 2 floor fans (if I get a wall mount AC), 1 hp water chiller, 7 27-gal containers for RDWC (6 plants, 1 control bucket), 1-2 110L air pumps feeding 26-32 air stones (if it is compatible with my nute choice), and 2 70pt dehumidifiers.

Thanks folks

DabS

they look cool, looks like it would do well with the gavs bro. 30k btu sounds like plenty i could be wrong tho.

I can grab 2-
Mitsubishi MZ-FH12NA 12,000 BTU 26.1 SEER Ductless Mini Split System for 1,800.00 (each)

The high seer vs 18 and so fourth makes it a more efficient unit, 2 of these bad boys opposing each other and the fans on the other 2 walls chasing eachother across the canopy should serve me well. The Cassette is wayyy too much vs the variety of wall mounts. I could even get 2 of the-
Mitsubishi MZ-FH15NA 15,000 BTU 22 SEER Ductless Mini Split Heat Pump for 2,087.00 (each)
and save money over the cassette. Anyone have an opinion which I should go with??

if ya wanna be cool kid get the ceiling but id do what yer sayin save money

If I can not get someone to tell me with math and/or science which of the following two will out preform and by what margin I just may get one of each and do a test, atleast for the ones who care to see in reality how much the SEER rating effects the effectiveness of the A/C, that its not all about the BTU.-
Mitsubishi MZ-FH12NA 12,000 BTU 26.1 SEER Ductless Mini Split System for 1,800.00 (each)
Mitsubishi MZ-FH15NA 15,000 BTU 22 SEER Ductless Mini Split Heat Pump for 2,087.00 (each)

Also, Ive seen the P series Mr Slim to advertised pretty expensive and as the best technology they have but its one of the ones that is NOT energy star rated.... What gives?

the ceiling cassets are for 2 things.

if you have a nice colonial home with lovely trim detailing you are not going to want an ugly casset hanging off your wall like some genital wart. they just look better.

2. they are for wide open spaces that have no adjacent walls owing to floor to ceiling glass, or wall fixtures.... builtin cabinetry, or even just giant open rooms.

they are very good in commercial drop ceilings. they make little suspension kits and flanges just for drop ceiling tiles.

they are easier to clean than you might think. the fan comes all of the way out with the cowling.

Dab Strudel said:

I can grab 2-
Mitsubishi MZ-FH12NA 12,000 BTU 26.1 SEER Ductless Mini Split System for 1,800.00 (each)

The high seer vs 18 and so fourth makes it a more efficient unit, 2 of these bad boys opposing each other and the fans on the other 2 walls chasing eachother across the canopy should serve me well. The Cassette is wayyy too much vs the variety of wall mounts. I could even get 2 of the-
Mitsubishi MZ-FH15NA 15,000 BTU 22 SEER Ductless Mini Split Heat Pump for 2,087.00 (each)
and save money over the cassette. Anyone have an opinion which I should go with??

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dont forget... you can get a single condensing unit with two cassetts. you just need the valve block and the parts kit.

there is also a real forced air handler available in 3 and 4 ton coils... they are like 900 bucks, but IMO are the last word in hvac.

with a real air handler you could throw on media air cleaners and duct the air where ever you want.

queequeg152 said:

dont forget... you can get a single condensing unit with two cassetts. you just need the valve block and the parts kit.

there is also a real forced air handler available in 3 and 4 ton coils... they are like 900 bucks, but IMO are the last word in hvac.

with a real air handler you could throw on media air cleaners and duct the air where ever you want.

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mmhmmmm I seee..... Tell me more about these ton size units. I am thinking of pushing this to a bigger room and running 8 gavitas and 6 bare bulbs. I dont have a fuck of an idea how to gauge how big of an AC I need so if you have any idea what id be looking at and a brand thats reputable in the higher tonnage AC units. Thanks bud

Dab Strudel said:

mmhmmmm I seee..... Tell me more about these ton size units. I am thinking of pushing this to a bigger room and running 8 gavitas and 6 bare bulbs. I dont have a fuck of an idea how to gauge how big of an AC I need so if you have any idea what id be looking at and a brand thats reputable in the higher tonnage AC units. Thanks bud

Click to expand...

you size your ac based on internal and external heat gains.

in your case your internal heat gains will be far and away higher than the external. the lamps alone will probably be like 70% of the total heat gain.

take the maximum watts to the ballast multiply by 3.412.

take watts to all fans, computers, what ever else consuming electricity and do the same.

thats your internal heat gain.

the external heat gain requires a so called "manual J" heat gain calculation. you CAN.... skip this but i would not.
you would however need a pro to do it for you unless you want to spend like 6 maby 10 hours learning about it and doing it yourself.

it will tell you the heat gain or heat loss from the outside environment based on a shit load of factors... wall r values, lattitude, soffit depth, elevation etc.

regarding the minisplits.

yes mitsubishi does have units up to 4 tons. but they are stupid expensive. around 4 grand online. condensing unit only.

to get multiple cassets going you need one of their manifolds... they are fancy deals with sensors and valves built in. when a cassette calls for cooling it opens its respective valve and refrigerant flows to the cassette. simultaneously the outdoor condensing unit speeds up a bit to accommodate the new cassette.

if you just want two cassetts on one condensing unit, and the cassetts are the same capacity, there is a fancy Y fitting you can get from Mitsubishi thats like 100 bucks.
it has no sensors or valves though. the piping must be 100% the same length regardless of how far away they are. they should have the same restrictions too otherwise they will not get identical cooling capacities.



just google Mitsubishi branch box.

this has a bit about it.

http://www.mitsubishipro.com/media/285016/mxz-8b48na_pac-aka31-51bc_tech&service_och468a_6-15-10.pdf


if it were me personally... id just buy a decent 15 seer york unit with a real cabinet air handler. going to cost far less than this minisplit system, but it wont be as flexable. however your loads are very close to static here... a minisplit is not warrented imho.

Dammit gnome, where are you? This thread is right up your alley...

weve gotta contact FB and see how to code in the name tag feature haha

Asslover said:

Dammit gnome, where are you? This thread is right up your alley...

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i saw you posting early on in the thread
so I knew the OP was in competent hands
but it looks like things have changed.

Asslover said:

.
The science, for me, is in the 10 years experience of growing in a sealed room in Florida and trial error

Click to expand...

queequeg152 said:

not being a cannabis guy, i dont grow indoors.

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if you had to choose which one of the 2 above to build your growroom, who would it be?

when someone has no real hands on day to day experience running, maintaining and building out growrooms.
when they give advice they aren't thinking like **A GROWER DOES WITH 10YRS EXPERIENCE*
most of the time they're not helping anyone advising them on the in's and outs of it

personally my
listen to asslover and get the mitsu mr slim!
two would be better and there's a GOOD reason for that
especially with the OP setting up an 8000KW grow

imo telling you how much money you can save by not getting the mr slim only reinforces what i believe
a person with no exp. won't benefit the grower in the best way possible.

listening and taking the advice from someone that hasn't had 1 day of indoor growing exp.can can make for some very expensive and hard *lessons to be learned* down the line.

the gnome said:

i saw you posting early on in the thread
so I knew the OP was in competent hands
but it looks like things have changed.






if you had to choose which one of the 2 above to build your growroom, who would it be?

when someone has no real hands on day to day experience running, maintaining and building out growrooms.
when they give advice they aren't thinking like **A GROWER DOES WITH 10YRS EXPERIENCE*
most of the time they're not helping anyone advising them on the in's and outs of it

personally my
listen to asslover and get the mitsu mr slim!
two would be better and there's a GOOD reason for that
especially with the OP setting up an 8000KW grow

imo telling you how much money you can save by not getting the mr slim only reinforces what i believe
a person with no exp. won't benefit the grower in the best way possible.

listening and taking the advice from someone that hasn't had 1 day of indoor growing exp.can can make for some very expensive and hard *lessons to be learned* down the line.

Click to expand...

it seems like this is the second or so time youve brought up the fact that i grow junk outdoors, though it might have been someone else i do not recall.

Note however that im offering advice on hvac equipment, something i have plenty of experience with, not growing plants indoors.

there is nothing particularly challenging about the hvac requirements of a grow room such as this. Whats actually far more challenging are the needs of a flexible space such as commercial offices with fenestration loads, occupancy loads, equipment loads,etc. probably the biggest complicating factor wold be the variable latent heat loads form plants constantly growing larger and larger, transpiring progressively more water.

to plan for such a load is probably the hardest thing i can think of being that the ashrae documents only cover plants one might encounter in an office space such as tropical species.

The fact remains though that a heat load dominated largely by a static number, watts of lighting and fans. this number, the internal heat gain is going to be 3 maby 4 times higher than the external heat gain, meaning the excellent variability of the minisplit units is not really warrented, as where minisplits absolutly destroy conventional systems is in their ability to ramp down to like 30% of their total capacity without having to cycle on and off. you get conditions like this in rooms with high fenestration loads from windows and doors etc where solar heat is raping the space for maby 4 5 hours, then gone all togther. this space is perfect for the VRF minisplits.

grow room is not like that though. the external heat gain will vary hour to hour, but not to such an extent that a minisplit is going to far and away out perform a single stage conventional split system.

in general they operate more efficiently yes, but IMO efficiency has to be tempered with realities of the entire cost of the install. thats why i offered my opinion there.
a minisplit system could cost you several thousands more quite easily.

on the other hand, the minisplits install requirements are trivial in comparison to a conventional split system, requiring brazing, thermostat wiring and duct construction.

the conventional system however, with a powerfull blower motor can be used in conjunction with a very good media air cleaner capable of filtering down to very small particulates without introducing a huge amount of static air pressure.
ducting can also be designed and distributed such that you carry cooled air right to where the loads are present such as windows.

you need to decide what system you want.

Mini-split air conditioning systems are versatile alternatives to window mounted units. The advantages that are provided by the mini-split air conditioners security, noise, no floor space is taken up, no big holes, no ducts, no heat losses, multiple design options, easy outside placement and lower utility bills. Also, consult the mini-split ac replacement NJ professionals to make the best decision which will benefit you for the long term.

4K per light and you should be good