[J_P_A]

Here's yet another HVAC question. How should the HVAC contractor size the HVAC for my HT? I guess he would need to know the heat load for the room? This is an area I know very little about.


My room will be no bigger than 19'x37' counting an odd space at the back and we plan to having 2 rows of 4 plus a bar at the back. We are planning to leave the basement unfinished initially, but I want to make sure the HVAC is sized appropriately, as it will be cheaper to do it right now, rather than add an extra HVAC unit later. I think our particular HVAC contractor prefers to use a single unit with multiple trunks, dampers, and variable speed blowers as opposed to multiple units. However, they do model the entire house, so it's not a jack leg company that just uses the square footage to size the unit.


I appreciate the advice.

 

[airscapes]

Check out this site and the 30 home owners license for the manual j software only $49. You can do this yourself with a small amount of time invested and you will know. Did this for my in-laws when we had Central air put in and all the contractors were WAY over sized from what I came up with using this program. We went with what this thing said and it works great!

Good luck and read on!
http://www.hvaccomputer.com/main.asp

 

[J_P_A]

Thanks for the link, I'll check it out.


Does this program calculate heat loading and CFM for a home theater correctly? I know you are not supposed to treat it like a living room or anything like that. I think I read that you can estimate it by using the same heat loading as a kitchen, but I can't remember for sure, and I can't find the post anymore.


I'm not too worried about the rest of the house. Our builder is very meticulous, and when I gave him the 3rd degree about the HVAC contractor he was able to give very specific answers. Not just this is what we do, but this is why we do it. With all that said, if the program can model a HT correctly, it may be worthwhile just for that one room.

 

[BIGmouthinDC]

CJO in his excellent Dark Night theater thread had these resources listed for HVAC


HVAC

Keep air velocity below 250 fpm (Dennis Erickson): http://www.avsforum.com/avs-vb/showt...d.php?t=808024

More info from DE: "You'll want two supplies (typically in the front of the room, high mounted) and two returns (high mounted) in the back of the room. You do not want air flow directly on any seating location. You do not want a velocity of more than 250 FPM through any vent (diffusor). You want the HVAC system to maintain a temperature of 70 degrees F with an outdoor temperature range of -30 to 100 degrees F and to maintain a relative humidity of not less than 25% nor greater than 50%. You want six air exhanges per hour and 15 CFM of fresh air per person." http://www.avsforum.com/avs-vb/showt...6#post16857696

Minisplit? http://www.minisplitsystems.com/cgi/...CFRNhIgodC0pBT A- ended up sharing with basement HVAC
http://www.avsforum.com/avs-vb/showthread.php?t=840921
http://www.avsforum.com/avs-vb/showthread.php?t=851028

acoustic ducting: http://www.flexmasterusa.com/pg/fdpp.php
http://forum.doityourself.com/showthread.php?t=328397
http://www.hvaccomputer.com/
http://www.energyvideos.com/bldvid.php?P=CA&A=5&S=hva
https://72.52.223.187/xcart/product....93&page=1&js=n

Per Ted White- Use linear slot diffusers.

 

[airscapes]



Quote:
Originally Posted by J_P_A /forum/post/20846634


Thanks for the link, I'll check it out.


Does this program calculate heat loading and CFM for a home theater correctly? I know you are not supposed to treat it like a living room or anything like that. I think I read that you can estimate it by using the same heat loading as a kitchen, but I can't remember for sure, and I can't find the post anymore.

I can not say for sure but I would use it as if the theater were a house with one room. You have to enter data about the room and the way things are built. The info provided by Big is probably more applicable but for $50 and some time spent it may be worth it. The users guide is a nice learning tool and I think you can download it without purchase so it would probably be a helpful read. If I recall it was only about 40 pages. I don't think the heat load of a projector and equipment is anywhere near that of a kitchen.. I think there was a free demo version which would be useful to play with while reading the users guide. I would guess by the time you were done with both you would know if the $50 would be worth while.

 

[J_P_A]

Thanks for the links, BIG. I'll read through those and see if it sheds any light on things. I guess the piece I'm still missing is how much heat needs to be removed. Does specifying a minimum air flow ensure adequate heat dissipation? I know Dennis has said that a resting body generates 500 BTU, but I don't know how that relates to people in a theater (I try not to fall asleep during the show

). Is that another parameter that needs to be addressed, or will the HVAC be able to handle that if I can move enough air?


I feel like knowing enough to build a HT qualifies someone to build a house from the ground up!

 

[J_P_A]



Quote:
Originally Posted by airscapes /forum/post/20846992


I can not say for sure but I would use it as if the theater were a house with one room. You have to enter data about the room and the way things are built. The info provided by Big is probably more applicable but for $50 and some time spent it may be worth it. The users guide is a nice learning tool and I think you can download it without purchase so it would probably be a helpful read. If I recall it was only about 40 pages. I don't think the heat load of a projector and equipment is anywhere near that of a kitchen.. I think there was a free demo version which would be useful to play with while reading the users guide. I would guess by the time you were done with both you would know if the $50 would be worth while.

I think basing the heat loading on a kitchen has more to do with the number of people in a theater than the equipment. But again, I'm not sure about that. Hence the questions.


I'll take a closer look at the software, and I'm going to ask what software my HVAC contractor intends to use as well. It would be interesting to know if they're using the same thing.

 

[airscapes]

you get to enter the number of people in the room when you are doing the manual J with the software. You can also enter the wattage of all equipment and lights etc.. it is a slick piece of software.