John Sayers' Recording Studio Design Forum Archive

I couldn't get any of the Movin' Cool PC 7 videos to work.

Anyone else have problems with them?

Yeah, all their videos seem to have been pulled. It may be that they've gone over their hosting bandwidth allotment for the month or something.

--Keith

sharward wrote:I'm going to assume that "a small amount of fresh air" is insufficient to provide enough ventilation to make up for the lack of operable windows.

So, I revise my earlier statements about the unit providing no fresh air. I will now say the unit provides insufficient fresh air and as such should not be used in air-tight small spaces as an oxygen source.

--Keith

Keith,

Actually my friend - you're very correct that this is an assumption on your part. The 2nd part of your statement is not something you can say with certainty - but is still only an assumption on your part. DOn't be so quick to make a determination after speaking with someone who obviously has no idea what the answer to your question really is.

One of the problems with dealing with service techs is that they are not engineers - and have no idea how any of the products are designed......., just what the test specs are and how to repair them (and some of them aren't even reallly good at that).

Believe me when I tell you that the engineering department knows to the cubic inch exactly how much fresh air is pulled into the room with those units - and the engineering department is the only department that can tell you with any certainty what that number is.

My initial guess would be that it's probably a reasonable amount of air based on the unit size and how large an area it can handle from a conditioning point of view.

Thus the larger the unit - the more fresh air I would expect to see.

Understand (as well) that the code requirements for fresh air are way above whatever anyone truely needs for breathing purposes - thus much less than you have in your room would still be enough to satisy your room requirements in the real world. This is one of those items that grows every time a new code revision comes out.

If you go back 50 years - fresh air wasn't even a requirement in design - and people wern't dropping dead on the side of the road like flies.

Sincerely,

Rod

True -- I am assuming, staying on the safe side -- basically, in my mind, a product is guilty until proven innocent, and specs are evidence of innocence on which to base the judgment.

I guess the point I'm trying to illustrate is parallel to much of the advice from the experts here -- just as we shouldn't experiment with untested and unproven wall constructions or acoustic materials and expect to be successful, neither should we make assumptions about A/C units that lack published specifications, especially in the context of following building codes. My "assumption" that it doesn't provide "enough" is kind of akin to the famous "piccies, (photos) or it didn't happen" concept: "specs, or it isn't so."

--Keith

sharward wrote:True -- I am assuming, staying on the safe side -- basically, in my mind, a product is guilty until proven innocent, and specs are evidence of innocence on which to base the judgment.

I guess the point I'm trying to illustrate is parallel to much of the advice from the experts here -- just as we shouldn't experiment with untested and unproven wall constructions or acoustic materials and expect to be successful, neither should we make assumptions about A/C units that lack published specifications, especially in the context of following building codes. My "assumption" that it doesn't provide "enough" is kind of akin to the famous "piccies, (photos) or it didn't happen" concept: "specs, or it isn't so."

Keith,

Understood and agreed - but in the case of this equipment - I would be surprised to see any published data - that because they aren't specifically designing it for commercial use - and residential properties don't typically have fresh air requirements that need to be met in occupied spaces even though commercial spaces do.

When I need info I contact the engineering dept so I can get the real deal.

That was my only point.

Rod

rod gervais wrote:. . . residential properties don't typically have fresh air requirements that need to be met in occupied spaces . . .

How do you figure? Here's an example of fresh air requirements for residential construction (City of Boise, Idaho, using IRC 2003).

Point taken on the "engineering department" thing. Do you think I should escalate the matter to them, or is this getting silly?

--Keith

A year later.... any more word on these units? Any further advice?

I'm currently researching HVAC in a detached garage studio, with two small rooms, totaling roughly 1500 cubic feet. I know, not much detail, but my personal situation doesn't warrant a huge interruption in this topic-specific thread.

Chris

Hi, Chris,

No, no further research or revelations... But in the context of my own project, I have installed a mini-split air conditioner and heat pump on my own, and a fresh air ventilation system will follow that very soon. All that's left on the mini-split work in my case is the hook-up to the main electrical service panel, then getting the refrigerant lines that I ran connected and the system charged up with refrigerant by a certified HVAC technician.

So, with those exceptions, mine is (or will be) in fact a DIY HVAC system.

Thanks for the question and for bumping this great thread.

Oh, and a belated response to Rod's comment about the "people not dropping dead like flies on the side of the road" -- a lot has been said about fresh air requirements in more recent threads here... I'll just say that SBS (Sick Building Syndrome) does exist (as you know and have talked about recently ) and I'd think that unlike buildings from eras past that were extremely "leaky" air-wise, these studios we're building are (or should be!) air-tight.

I'm obviously not trying to teach Rod anything here... ...I just saw that comment and I wanted to bring these points into the record.

--Keith

what type of refrigerant are you planning on using? I've just had central air installed and they used a newer kind - R-410? which replaces R-22 freon (which will no longer be allowed in new equipment after 2010 and completely gone by 2020...) because we didn't want to get stuck in a few years possibly not being able to readily re-charge the system...

http://www.epa.gov/ozone/title6/phaseou ... seout.html

http://www.epa.gov/ozone/snap/refrigera ... omeac.html

My system is a Sanyo 09KHS71, which is 16 SEER and uses R-410A (a.k.a. "Puron" and "Genetron R410A"), a newer refrigerant that is replacing R-22.

R-22 is not compatible with R-410A.

--Keith

OK...I'll jump in here with my long-term assessment of this unit. I have the Mac-12K in my little, free-standing practice room. It's not bad, but barely does the job here in Texas...in the summer that is. Last summer it was fine, just a bit hot. This year, we had an incredible amount of rain in June and things felt more like Houston or Atlanta than Dallas, so I have been fighting humidity more than anything else. Maybe it was the spilled beer doing this, I'm not sure.

I really have tried to keep the unit set higher, like 78 during the days and just crank it down a few hours before practice to keep the bills lower. I do need to work on a better ventilation system in the room, but haven't done that yet. That'll make a good winter project. But, no one has dropped dead from lack of oxygen yet.

later,

m

i'd like to resurrect this thread with a question. if i get no response, maybe i'll post a new thread.

its a little too late, but i'm thinking about cooling of my studio. its a SMALL 1 room plus a vocal booth.

my build is here:
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8205

my question is this. . .
can i use a free standing unit (ie: the Mac-12K) to cool the room, and to take care of the 'fresh air' issue, just open the door in my studio (that leads outside) every couple of hours, for a couple minutes?

this will let hot air in, and make the process of cooling it start over, but at least give some fresh air.

any comments on this idea?

The answer to your question is that - yes - this is a legal, code compliant - option for you - the door opening directly to the outside being the main requirement to be met

Rod

thanks for the quick response!

i'll start researching best unit soon.
its autumn now, so i won't be needing it for a while.

I'm making drawings for a new to build studio and now i'm at the point of making the HVAC layout. (http://www.johnlsayers.com/phpBB2/viewtopic.php?t=11110)
I also live in The Netherlands and don't know a lot about airconditioning systems too.

The studio i'm planning to build has multiple rooms. What I don't understand in a lot of HVCA designs is that the rooms make use of the same ducts. When they are connected don't you have an open connection from one to another room? In the drawing they used "overspraakdempers" (sort of damping?) but how is this done?

Like shown in the image: