# HVAC



## sparkymt (May 19, 2010)

I am in need of help in finding reading material or any info that will help me figure out how to set up the HVAC for my room. I have been looking through the threads, but I'm not finding the detailed "how to" info that would help me figure this out. Can someone please point me in the right direction?

Jon


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## bpape (Sep 14, 2006)

What are you looking for specifically? BTU requirements? Soundproofing? Quiet in-room performance?

The basics:

- Treat the room as a high BTU situation. Don't skimp on the return side of the hvac. That's how you get the heat out.

- Don't use tin ductwork. It's just a huge noise amplifier of sound getting out and fan/blower noise getting into the room. Flex duct or duct board inside isolated MDF boxes will be much quieter for both noise paths.

- Depending on your location, make sure that you can always cool the room. This may mean a separate unit for the HT in climates where you have to run heat to the rest of the house in the winter.

- Try to get a unit that is as quiet as possible and decouple from any rigid ductwork that you have to use.

Bryan


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## mrloofer (Mar 27, 2010)

Look at mini split systems. I put a 1 ton Haeir unit in my 12x18 room and it's plenty adequate to cool the room. Cost me $675 but factor in a couple of hundred for copper pipes and getting a pro to vacuum the lines.


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## sparkymt (May 19, 2010)

"What are you looking for specifically? BTU requirements? Soundproofing? Quiet in-room performance?"

All of the above. 

I need to know when I should start working on the hvac. Can I frame first, or do I need to have the ductwork to the home theater room set up before. 

"Don't use tin ductwork. It's just a huge noise amplifier of sound getting out and fan/blower noise getting into the room. Flex duct or duct board inside isolated MDF boxes will be much quieter for both noise paths."

I do plan on using flex duct with some type of sound proofing to it and isolate with MDF boxes. I've read about using silencers, but I am not sure how to properly implement them.


"Look at mini split systems. I put a 1 ton Haeir unit in my 12x18 room and it's plenty adequate to cool the room. Cost me $675 but factor in a couple of hundred for copper pipes and getting a pro to vacuum the lines."

Interesting....I've seen mini split systems at local new parade of home shows, but I've never looked into them. I have not seen many people use these in their home theaters. It might be something to look into. Thanks.


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## bpape (Sep 14, 2006)

Mini-splits can be a very effective solution if you want complete isolation. There is some minor hardware outside the room but no ductwork. 

For the other, it's hard to say as I don't know your particular situation, where you can run things, if ducting could potentially be done after the room is built by using soffiting for routing, etc.

Silencers can work pretty well but not usually for bass transmission.

Bryan


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## Dennis Erskine (May 29, 2010)

> Can I frame first, or do I need to have the ductwork to the home theater room set up before.


Plan first. Then frame. Ready shoot, aim is a clear path to problems.


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## sparkymt (May 19, 2010)

Okay, I called in some HVAC guys to look at my basement and figure out what I needed. I tried to explain that the home theater room would be sealed and that it needed to be treated like it was a kitchen. Also I had them look at zoning the entire system.

They wanted to use the duct work for the room that was being used on the living room above. I told them that I was trying to sound proof the room as much as possible and that I did not want to use other current duct work for this room.

Needless to say I got some weird looks. I hope I was explaining what I needed correctly.


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## bpape (Sep 14, 2006)

Kind of like trying to explain pretty much anything else about a dedicated home theater build to most tradesmen who haven't done one RIGHT before. Hang in there, you'll find somebody who wants to learn.

Bryan


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## sga2 (Nov 14, 2009)

A mini split is a very good way to go, if you don't mind having the unit inside the room (they are very quiet, but not invisible...). Alternatively, you should consider adding a ducted system to your basement, just locate the unit as far from the room as practical and follow other ductwork acoustical treatment advice found all over this forum. I would not recommend sub-zoning off the main floor under any circumstances. It will cost nearly as much as (maybe more than) a new separate unit, will not offer great control, and will rob the main floor unit of capacity.

I (and others) can offer some advice on capacity if we have some info. How big is the HT room? How many people do you plan to accomodate? Where will the equipment be located? Also, are any walls exposed to outdoors?

Regards,
sga2


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## randyox (May 19, 2009)

I ran into a similar problem with questions regarding HVAC. I contacted one of my local CEDIA installers and they gave me the name of a couple of HVAC guys who had done work in home theater environments. I was able to get an HVAC guy out and he told me what I needed to know... in fact... he gave me an incredible bid to simply do the work... almost at cost... well worth the few phone calls it took to get it done right... just a thought...


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## philmadxx (Dec 17, 2006)

Mini-splits - Pro - small, cool well and minimize penetration size outside of the room - no ductwork. Con fan noise, refrigerant pipes, dedicated power, condesate drain required, etc. None of these are deal breakers but they add up. 

A separate zone or dedicated system - Pro allows control of the temp, allows for the possibility of bringing in fresh air, cools and heats more evenly, quieter. Cons - mostly duct work related, larger penetrations to outside of the HT.

I steer away from mini-splits when I can - they have their place but mostly when nothing else will work. I have had and seen too many problems when condensate lines get clogged or pumps go bad. No one likes wet carpet in their HT. I like to zone existing systems or install dedicated DX systems. I specify sound lining in the ductwork - oversize the ductwork to keep the velocity (and therefor noise) to a minimum and I duct in a small outside air supply to give fresh air. Same goes with return air ducts - big, lined and on the opposite side of the room from the supplies. 

Good luck

PM


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## bpape (Sep 14, 2006)

A good mini-split system need not be noisy at all. The Mitsubishi Mr. Slim series runs at 26, 30, 40db IIRC depending on the fan speed. 26 and 30db are below the ambient noise floor of pretty much every room out there. ie - you'd never hear it. To me that's the big one.

I'll trade off smaller penetrations, no transmission of noise via ductwork to the rest of the house, etc. for a dedicated outlet and one small chase to the outside.

Every room is different. No one thing is going to work best in every situation. If you can do a separate, dedicated system other than a mini-split just for the basement or attic zone, absolutely, go for it - just a LOT more expensive.

Zoning doesn't help with sound isolation. There's still the issue of having to do bent, isolated ducts which reduces efficiency and in some cases, can require powered duct fans to help with the flow so you're right back there with fan noise again and lose the isolation at the same time.

Understand about the condensate line. Like anything else though, it's a matter of planning and maintenance. 

Bryan


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## philmadxx (Dec 17, 2006)

The Mr. Slims are good units - no doubt and I've installed many of them. 

What I like about the ducted systems are that you can put supply where it is needed (outside wall?), returns where they are needed (interior walls, over projector or other heat generating equipment) and get a much more even temperature than you can with a single source unit. of BTU's are not the whole ballgame, you have to distribute the air in the room, in many cases, with large or oddly shaped rooms, you have to crank up the fans on the minis to get air where you need it - that can introduce more noise. The other problem I have with them is having to look at them (this from a guy with a subwoofer the size of a small couch) - do they make them in black yet?

Minis are great in some instances but one should explore all of the options and choose what is right for their application. 

Make sure you have access to a drain for the condensate - you have to pump it otherwise - again not a big deal but something to consider.

PM


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## fitzwaddle (Aug 25, 2010)

philmadxx said:


> The other problem I have with them is having to look at them (this from a guy with a subwoofer the size of a small couch)


There's the LG Art Cool that looks a little nicer - but isn't quite as quiet as the Mitsubishi Mr. Slim. I've been debating using the LG in my room, still waffling. Mitsubishi also makes a mini split where the fan mounts in the ceiling, not sure if its flush mount or hangs down a little, looking at the manual now - I wonder though if the big hole that it mounts through would be a problem for sound isolation.


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## davey_fl (Sep 16, 2010)

We have the Mitsubishi mini split system and it's very quiet...


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## Ted White (May 4, 2009)

So... How did you make out with the ventilation questions? Feel free to send me a PM with your email address. We have a few articles on sound isolated ventilation.











This is at the heart of the system


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## sparkymt (May 19, 2010)

thanks for all the help. I really liked the idea of trying to find a cedia certified installer in my area and using their cooling/heating person. Unfortunately there was none to be found within 250 miles of me.  

Thanks Ted for the pic. That is the plan I am going with.

So...I pretty much had to go with my gut on the best hvac company and trust they they would do me right. The work they did looks okay to me, but what do I know. I'm no expert. I won't really know if they did their job until I get the room finished.


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