Air Conditioning using micro vents

john wood

Each manufacturer has a certain way they want you to install the system. Emphasis here on SYSTEM. If you choose a mfg, then you will be using their distribution ducting so you will need to rough that in early.

Try looking at Energy Saving Products HiV equipment. End of run has a 90 with a damper built in. Easy to fit into a 3.5" cavity.

www.hi-velocity.com

Gavin Pitchford

Air Conditioning using micro vents

As the longest winter in 10 years seems to be ending, a young man's thoughts turn to ... Air Conditioning!

Can anyone recommend a site for help with AC issues ?

I have opened up an 1890 home to the studs and will be adding an AC unit on the top floor to feed micro forced air vents in the future. In the interim, I want to take advantage of the lack of drywall to rough in the vents and pipes to feed them and was unsure of what to use for pipes. Home Depot recommended PVC pipe - either the black thick wall or the white thin wall waste pipe and I wondered if anyone could comment ?

If PVC is useable for this application, could anyone comment on the impact of condensation on these pipes ?

What kind of diameters ? Split feeds ? etc. should be used.

Any help or referrals would be much appreciated.

Ben_3

Gavin

I have just one word Space-Pak, well two words really, Don't fool around with pvc I have only used this for underground ducting to be buried beneath a slab. Space-Pak is great but you have to know how it works and do the proper calcs, or you won't have anything but a headache. You could visit their site and they might have a contractor near you. But it is not something I would suggest you undertake on your own.

Ray M_2

a/c

The one word is unico.

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Mark A. Custis

One word or two words

The big deal is to properly size the anticipated load and therefore machine size. Once having establish what you need then you can go about rough in for the ducts. I would only use material designed to go in walls and have HV cold air running through them.

What a mess you can make with condensation and then the toxic mold stuff is incredable.

While I was at it I would make arrangements to pressurize the building and provide adequate make up air for combustion. Now would be the time to address any additional indoor air quality issues.

Paster or wall board once its up you cry if it must be reopened.

Good luck,

Mark

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Ben_3

IAQ

Whether it's space-pak or unico it dosen't matter the designs are very similiar however there are some diffs. One of the things that make these systems great is they cool by aspiration not convection and throw, almost radaint cooling. The HV air stream @ it's velocity draws the air in the space slowly to it to create an almost draftless cooling with a better humidty control. Many times these systems get a bad rap due someone elses botched installation but if you go room by room and figure your loads, tubing lengths, and amount of outlets per room so that the system is balanced and correct in size I still feel you can't beat it. This draft less cooling also helps to cut down on the amount of IAQ problems assoc. with a conventional system and you can even put EACs on them. There are two different mfg. out there that offer a 1" 24 vac media air cleaner that I have had much success with Just watch to make sure it's not to much restriction.

Gavin Pitchford

Thanks for the referral to Unico.

I expect to install the system in what is now the attic - but what will become the third floor after the reno is complete. I have looked through as much of the Unico stuff as I can see would be useful, but couldn't get a clear picture of whether or not it was to be installed fully inside - or "half and half". I assume that there is hot something (air ? Water ? coolant ?) produced somewhere, that must leave the house. (I am expecting that there will be an outside area with a flat surface or a deck at the same level, if it matters.)

If it is an inside based system can it exist in a living area ? or will it need it's own special - sound proofed - space ?

The web site gives a good look at their flex-duct - Thanks for answering that question.

Ben_3

Unico

Gavin, it installs just like any other A/C system with a blower inside and a condensing unit outside. But please find a contractor who is familiar with these systems either Space-Pak or Unico to do the proper calcs and sizing or it will never work right. It is not just feeding them through the walls. Mant times we put these systems in finished homes and hide the tubing in the walls, a costly and labor intensive install, If your walls are open I,m sure you would get a much better deal. Also a benefit is they can install into smaller places then conv. units so you can put it just about anywhere.

Mark A. Custis

Way to be Ben!



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Gavin Pitchford

12 (some of them dumb) follow up questions...

Thanks for all the advice so far.

As I read the Unico and Spacepak web info, there seems to be 3 components: (1) an air handler / fan, (2) a cooling device, and (3) a condenser unit. Items 1 and 2 go inside and Item 3 outside. Is that correct ?

Have I understood properly that both the Unico and SpacePak people provide a cooler and an air handler which are both in the units described (i.e. the Unico M3642), but both require a third party condenser unit (to fit their spec) - OR does this unit ALSO require a cooling unit to be attached ? If so, does the cooling unit fit inside the Air handler device, or is it in a seperate device and air sucked through and into the air handler - And if so:
1) how big are these units (roughly)
2) can they be placed in an enclosed, insulated and soundproofed box (accessible for service) in a living area - or are they simply too noisy or do they need to themselves be cooled while operating ?

It is my intention to try and find a professional to handle the design / unit sizing etc. and identify where the electrical connection needs to be and to what spec - but to install the 2" duct (and any plumbing plus the electrical) myself do parts of the 7" plenum and the small runs at different times as I have different portions of the house opened up - and then have the "pro" come and install all the AC unit after the reno is complete. Would anyone likely sell me the ducts only ? Or do contractors only want the "whole job" ? ( I appreciate a skilled trade does not want to rely upon shoddy workmanship of another, but my workmanship is top rate (provided I understand the spec - i.e. no 2" runs coming off the plenum less than 12" apart, no 2" runs longer than 10 feet ideally and 50 feet max, turns no tighter than 6" radius)

And finally, can you give me a ballpark on the cost of the 2" ducts on a per foot basis (US or Cdn dollars - but please specify)

Ben_3

12 answers

1-12 Call a qualified contractor. I don't want to sound mean but I have seen many A/C contractors mess up these installs which usually only brings a bad name to the product. To answer some of your questions the unit comes with the blower and cooling coil packaged into one air handler. This must be connected to a condensing unit {i.e. the compressor} which is located outside and should'nt be to obstructed. The process of refrigeration is what does the cooling via the coils and freon with out getting to detailed. What you are asking is for a contractor to size and design the job, which will require the knowledge of how long each run will be and how the plenum duct will be run in which outlets to install orifice plates, etc. Then to instuct how much of this you will need where to put them and to sell you the tubing at his cost. Then to come back and hook the A/C to a system and possibly waranty this unit. I truly understand where you are coming from and that you want to save money and understand your system. But when all is said and done you will probably be happier if someone who does this often handles the job. I'm sure you can do nice work but so much of the design is affected by the install. And it would be a shame, if after it was all done, it didn't keep you cool.

tombig

Well Said

Very well said Ben. You must get a contractor involved early in this process. Indoor unit location, heat loss and distribution designs, trunk line runs,condensate removal,all must be considered before anything gets installed including tubing runs. If you're handy enough and can get some of your 'sweat equity' built into his price go for it. It sounds to me like you just want to get some distribution work done while the walls are open. If you just slap some 2" in the walls from where you THINK the outlet will be to where you THINK the trunk will run you're asking for trouble.

Floyd

And....

stay away from HD... if the guys they had working there had any REAL knowledge ....

They would be out working for themselves... and not making peanuts giving people very poor advice!!!!!!

tombig

Hey Floyd

> stay away from HD... if the guys they had working

> there had any REAL knowledge ....

>

> They would

> be out working for themselves... and not making

> peanuts giving people very poor advice!!!!!!

tombig

Hey Floyd

How was the trip back to PA. I want to travel there and see them thar hills. Don't tell me Big Boxes are selling hi velocity AC systems out there. They must be nuts.


Tom Goebig

Floyd

The trip back was great!!!!

AND no SNOW!!!!!!!!!!!!!!

Let me know when your comin'... I'll pick you up in Wmspt. and show you some really beautiful mountains!!!!!
Take you out to supper at the "Turkey Ranch", and take you on a 100 mile ride and you won't have to wait more then one turn of the light at any intersection!!! :-) God, that ride back to Chi town was aggravating!!!!

I don't know that the big boxes sell hi vel. systems... but they sure do screw up everything else they try to sell!!!!!!
Can't understand why people think some guy in a store knows squat!!!
Most of them are flunkies or done it so long ago they forgot more than they know!!!!


Floyd "God's Country" Kolb

tombig

Especially

aggravating to someone who's not used to it. According to Old Style beer commercials circa 1970's, 'Gods country' was in northern Wis. but I'll take your word for it.

Tom

Brian (Tankless) Wood

Are you related to \"Pink

Floyd" :O) After a 14hr day, and a coupla cool one's I'm "comfortably numb".

I thought God resided in "The Bible-Belt" of the South??
Am I happily made to believe that He resides everywhere, all the time, for everyone (even in the frozen north)? Yes, phew, what a relief.

I wish HE would blow some cool air south, into that 120* attic I was in this AM & PM

You guys are talking snow, we are sweating our a*&^ses off. LA has two seasons, summer, and not-quite-summer.

"Shine on you crazy diamond" & "wish you were here" or I were there.

Brian (two beers, I'm not cheap but can be had) Wood.

Gavin Pitchford

The Division Bell is ringing...

What is this - some DIY type posts a dumb question (I mean, it's not like I asked if pigs can fly !) and the WALL travels to the Dark Side ?

Thanks to all for the invaluable insight and referals.

Anyone have great stories or nightmares to relate about any of the High Velocity systems noted ?

Some of the runs will have to cut through the double (true) 2x4s top plate on supporting walls. I would prefer to push a same 2" i/d but smaller o/d coupler through the top plate and join the regular vent on either side - and try and maintain some structural integrity (and reinforce the top plate on either side). Do any of the systems have that option - or am I worrying needlessly about cutting the top plate ?


Run Rabbit Run...

Brian (Tankless) Wood

Anyone who knows

that much Pink Floyd, and is leading his customers in the High Velocity direction, must be ok.

I've mostly been involved with ESP www.high-velocity.com, and I aggree with their thinking: Keep all 2" mini-ducts the SAME length, with no tight bends, and the systems become self balancing.

Teach your customers not to be "Just bricks in The Wall". If you don't eat your meat, you can't have any pudding. My metal-work teacher was EXACTLY like the guy who said that in the movie. I didn't like him at the time, but he made a lot of sense, in hindsight.

It's 66 here already, and 80 tomorrow, weird weather eh?.

Later, Y'all.

Swampy.