Ventilation for HT addition? (1 Viewer)

[kalm_traveler]

Long time no see everyone!

A lot has happened since I was asking about speakers and subwoofers 2 years ago, and the room is actually almost finished.

That being said, I recently got off my duff and finished the drywall, painting, etc and and quickly realized this room is so sealed up now that there is next to zero airflow.

As a refresher, the room is an addition that runs along the back of the house, what used to be I believe a rear walk-out deck was converted into a long addition above the rear porch. The HT room is approximately 12' W x 24' D x 8' H with a door into the house in the rear right corner, right wall, and door into my bedroom in the same corner on the back wall.

Initially, it had 4 4' x 5' windows - 2 on the left wall and 2 on the front wall (behind the TV) but I finally framed/drywalled them all up.

How would you guys recommend I get some ventilation going for this? My bedroom which is behind the HT room still has it's giant window, so I can open that up but there is nothing to move air through the HT room itself and I've been resorting to running fans to try and blow the air in there around enough to get some fresh air circulating.

The only idea I found on Google that seemed like it might work was to put maybe an 8" fan up in the attic blowing outside (on the side of my bedroom) connected to some insulated flex ducting with a few 90 degree bends to help with silence, then a vent on the other side of the house with more insulated flex duct and 90 degree bends leading to some air duct vent in the ceiling of the HT room opposite side of the fan.

This way it would in theory drag air into the HT room from the cool side of the house, and blow it out above my bedroom on the opposite side.

Thoughts or suggestions?

 

[kalm_traveler]

This is a rough sketch of sort of the layout...

 

[Adam Gregorich]

I think you might find that depending on your space, cooling might be more important than heating. I remember a few winters ago the AC running in our HT when it was 22 degrees outside. Between how tightly the room was sealed up for sound blockage, plus the acoustical insulation, and heat from people and equipment, it needed cooling, not heating.

I actually just re-read your post and I'm not sure if you are wanting to heat/cool the air, or just replace stagnant air with fresh air, or a little of both.

 

[Alf S]

A bit off topic...

Seems you have just one seating position that offers "the sweet spot" to even watch a movie and enjoy surround sound?

Seems most viewers are forced to sit sideways along the walls to watch the TV?

Any plans to arrange the sofas to allow folks to really enjoy watching a movie in there vs. twisting their necks to see it? Setup just doesn't seem user friendly for "Home Theater" style viewing.

As for heat/air, would this zoned system option work down there? http://www.mitsubishicomfort.com/

 

[CraigF]

No help, but I commiserate.

When I was finishing up my room, like Adam I needed to "seal" it to get the final full control of the sound, after the acoustic panels and everything else was done. I should have known better... I'm running many channels of amps that all run in Class A, which means "always hot". Even modest natural airflow through tthe room's two doorways/entrances (quite wide) at opposite ends of the room previously kept temps under control. Close those off and even in the winter up here it gets sweltering. In a "sealed" room, internal fans won't help, though they might make you feel cooler, for a little while.

So...exhaust fans. And new "doors" for the openings. Or a very quiet but large fan positioned such that if I leave the entranceways a bit open, I can force a flow-through ventilation. That latter works very well, nobody more surprised than me, considering how relatively small the fan is, it's a brand I'm not keen on, and it's a really nice-looking fan too (with a remote control of course, Harmony and such can learn them). It looks like you effectively only have one doorway since they're in the "same" place, so that's an obvious flow-through issue.

Fan at the business end blowing towards the doorway is about the best I can suggest. Unless you can exhaust to outside, but an effective exhaust fan tends to be quite noisy unless somewhat large, and you're getting into real work that needs to be done properly by pros. Might even work fine if you put a (pedestal) fan near the sub near your computer desk, blowing towards the open doorway, it doesn't take a lot of airflow to move the hot air out. And since it's behind you you won't notice any noise it might make so much.

 

[kalm_traveler]

Thank you for the responses, and I apologize if it sounded like my concern is heating/cooling. Actually I already have 2 ductless mini splits coming in (one for each room) to take care of temperature.

The concern is just preventing the air from stagnating, since with all the giant windows removed, there is currently nothing bringing fresh air into the space.

As mentioned in my first post, the only feasible thing seemed to be to add in forced air circulation with new vents etc, as this part of the house is not connected in any way to the home HVAC system.

*EDIT*

Alf S - that is correct. 90-95% of the time this is used only by me as I have not yet found my future missus, and most of my friends are too busy being young to middle-aged fathers to have time to watch a movie.

Suppose I could push the computer desk farther back and have the theater seating something more like a 2 row setup with 3 in front and 2 raised slightly behind them? This honestly hadn't crossed my mind since i'm usually watching solo.

 

[CraigF]

Hey, I'm usually watching solo too, at least the first time I watch a disc (would drive most normal humans crazy, going back to hear some good dialog a few times, re-watching some good action, cranking it *real* loud if I like the music...you know).

I have my best-hearing-positioned couch on those Teflon/slidey things, and I push it right out of the way unless needed. My chair, the chair that is mine, is in the optimized position. I replace my chair with the couch so 3-5 people will get it pretty good.

Stagnation is still airflow, similar solution as too much heat, but easier. If it's True Stagnation (the title of my next movie), then a fan will surely solve that, since it's just a matter of moving air around and not about air replacement.

 

[kalm_traveler]

My concern is that without fresh air coming in the oxygen will be depleted and I will die whilst watching a Lord of The Rings extended edition marathon.

As it is, the air gets pretty stuffy after just a few hours in there without any exchange happening.