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Kinetic River Cinema - Page 9

post #241 of 597
Thread Starter 
Good, then i have a plan. Took a while but I got there!

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post #242 of 597
Quote:
Originally Posted by Ted White View Post

Fair enough. We disagree is all. If I didn't have 11 years of using my system, I might feel differently, but honestly it was cheap and very effective.

The only thing we disagree on is that I don't see it as a first-choice option, particularly when everything is being built. If two fans, one or two controllers, flex duct, the additional electric, Green Glue, lumber, duct board, etc. is $600 of total materials (about 55% of which is the cost of the fans) and is able to cool to roughly ambient, I do not disagree that it is fairly cheap and fairly effective. But if it is $500 more to hire professionals to engineer the system and buy / install the materials then it is probably a worthwhile expenditure to have the engineered forced air system handle 100% of the room's conditioning without the need for a secondary or supplemental dead vent system, then that saves a lot of construction hassle and brings everything into a common, controllable system.

@DAVID - you may want to call these guys: http://www.hvacpartsoutlet.com/ or these guys http://www.bestbuyheatingandairconditioning.com/ Either may be able to help you with your system design (typically for free) and ship all the parts you need to your doorstep. They also offer advice on proper installation as service for their sale. You will still have to do some of the legwork in being their eyes and ears, but it could be another option for you.
post #243 of 597
Quote:
Originally Posted by brausch View Post

1. If he lives in a cold climate, the condensing unit would need to capable of operating during the winter. I had to get a "low ambient" kit for my split system to allow the unit to cool in the winter.

The AC and condenser would operate in the winter? Meaning no snow on the outside unit? I'm interested in this, as I would have deemed this a real long shot to implement.
post #244 of 597
The Dead Vent is simply a muffler. Can be used in conjunction with the main HVAC loop or independent of it, though it is often (incorrectly) exclusively associated with stand-alone systems.

Most often these are considered during remodels. If the whole house is being built new, then we have many more options avilable, obviously.
post #245 of 597
Quote:
Originally Posted by Ted White View Post

The AC and condenser would operate in the winter? Meaning no snow on the outside unit? I'm interested in this, as I would have deemed this a real long shot to implement.

Ted - this may answer a few questions regarding low-ambient startup: http://www.midtninspections.com/low-ambient-start-up.html

You are correct - the unit must be free of most snow and debris prior to running. Snow fences and other temporary barriers around the unit can also help.
post #246 of 597
Thread Starter 
HVAC guy is coming back over tomorrow and we'll see if he can understand what I am trying to accomplish. Will keep you posted Tim.
post #247 of 597
Quote:
Originally Posted by Ted White View Post

The Dead Vent is simply a muffler. Can be used in conjunction with the main HVAC loop or independent of it, though it is often (incorrectly) exclusively associated with stand-alone systems.
Most often these are considered during remodels. If the whole house is being built new, then we have many more options avilable, obviously.

@Ted - If you have been following my posts on this thread you will see time and time again that I think the dead vent is a great idea to use with forced air HVAC systems as a relatively soundproof way to get large duct openings through the soundproof shell. I just dislike it as a standalone or supplemental system unless it is the only option (i.e. after-the-fact or "quick fix" approach). As many of the theaters in this thread are from the ground-up with rough space being converted to finished space, there is plenty of opportunity to engineer and implement a 100% forced air HVAC solution correctly as the preferred option over all others.
Edited by TMcG - 7/26/12 at 5:59pm
post #248 of 597
Thread Starter 
I agree. At a minimum I will have a closed loop return and supplies. Not exhausting or pulling ambient air from other rooms. I will have to get creative with my hvac runs but its doable.
post #249 of 597
Thread Starter 
Plans are set for HVAC. Took a while and thanks to all, Tim specifically for sharing.

Two 6" supplies penetrate the room at around the half way point on the sides of the room, in the ceiling. From there the supplies will run in the side soffits and terminate at 2 diffusors at the front of the room above the stage.

Return will be at the back middle wall. The run will be 8" flex running through a joist (joist muffler) and returning to the Main Return on the air handler.

Now to address the issue of heat in the winter. The problem as addressed in previous posts is that with a room below grade the ambient temperature outside of the room will be around 55 degrees. The rest of the zone will be calling heat (thermostat is on the first floor) because the temperature outside of the house on the first floor will be freezing. The HT will have heat flowing into the room at the mercy of the upstairs thermostat. Add several people into the mix and I assume the HT will heat up pretty fast.

Because I am not creating a separate zone or doing a mini-split I will need to get cold air from somewhere. To accomplish this I will pull outside air into the room via Dead Vent. There will also be a thermostat inside the HT and a temp sensor. The thermostat, relays, control board, etc will dictate when the DV turns on, when the mechanical dampers in the supplies will shut and so on. I will have to play around with what temp to set the thermostat at as well as placement of the temp sensor.

This is not a perfect solution but it is what I have to work with. I should be able to keep the costs below 1k, including dampers, in-line fan, thermostat, temp sensor, and controls.
post #250 of 597
In the winter - while the main level of the house is calling for heat, but the theater needs cool - a separate thermostat in the theater will close the dampers for hot supply to the theater from the main system, then open and power fresh cold supplies of outside air - do I have that right? What balances this airflow? return to outside or return into the main return (back to the main level of the house)?

Like you said, you'll need a little experience with it to get it set to the right levels, but overall, it sounds solid to me.

I'm interested to see what equipment you decide on. smile.gif
post #251 of 597
Thread Starter 
Yes that is pretty much the premise. The dampers and in-line fan will be directly controlled by the thermostat; turning the DV on, supplies off based on reaching a temperature of 'X'. The HVAC company that i have been working with is drawing me up the schematics to do the wiring, free of charge. I just need to figure out exactly what I need to purchase. But I will keep everyone posted to include schematics, equipment, and cost. And of course pictures which I have been slacking on lately.
post #252 of 597
Quote:
Originally Posted by fax6202 View Post

Now to address the issue of heat in the winter. The problem as addressed in previous posts is that with a room below grade the ambient temperature outside of the room will be around 55 degrees. The rest of the zone will be calling heat (thermostat is on the first floor) because the temperature outside of the house on the first floor will be freezing. The HT will have heat flowing into the room at the mercy of the upstairs thermostat. Add several people into the mix and I assume the HT will heat up pretty fast.
Because I am not creating a separate zone or doing a mini-split I will need to get cold air from somewhere. To accomplish this I will pull outside air into the room via Dead Vent. There will also be a thermostat inside the HT and a temp sensor. The thermostat, relays, control board, etc will dictate when the DV turns on, when the mechanical dampers in the supplies will shut and so on. I will have to play around with what temp to set the thermostat at as well as placement of the temp sensor.
This is not a perfect solution but it is what I have to work with. I should be able to keep the costs below 1k, including dampers, in-line fan, thermostat, temp sensor, and controls.

You had me right up until this point above. I thought you said that your upper floor is on one zone and your basement is on a second zone and that you have motorized dampers allowing for control of which zone (or both) gets the conditioned air at any one time. Second, isn't the rest of your basement going to be finished out and conditioned space so ambient temperature will be way above 55 and at "normal" indoor household temperatures? I thought the goal was to zone off the theater separately but tie it in to the primary HVAC with the right "brains" controlling the system and giving zone priority. Is that not the case?

Third, and most disturbing, is this guy's recommendation to pull outside air into the room via Dead Vent. How is this air brought in under a controlled fashion? Devices called EVHR (Energy Ventilation Heat Recovery) are designed for fresh air exchanges with the outside and provide a sealed, filtered method for air exchange. But these are pricey to have put in and installed - about $3k at minimum depending on the unit. If it is truly just a pure vent, you will be introducing humidity, dust and bugs into your theater environment - guaranteed. How will this be handled with the HVAC guy's recommendation?

I am a bit confused and should probably go have a beer now....
post #253 of 597
Thread Starter 
lol...now I am confused as well. A beer is definitely in order. The basement and first floor are on one zone. The top floor is on its own zone. The only time that the outside vented air would come in would be in winter where humidity will not be an issue. To the rest of your points, I will certainly bring them up. I am absolutely sure that with my supplies and return that I will be ok, except for possibly the winter time like we are discussing. I just dont see any other way around this issue with my budget.

What if I just added the thermostat, temp sensor, and dampers (left out the DV). When the temp gets to X degrees the dampers close completely. I guess then the issue would be the return still pulling air and the room going into a negative. Im really not sure where to go from here.
post #254 of 597
OK, so I take it that you have three floors to your house . . . a second floor that has its own unit and a main floor and basement that share one unit but have no dampers - correct? This is different from the way I thought you were explaining it before.

Assuming the area outside the theater is conditioned, you might as well just ventilate to ambient with a separate dead vent system (as per Ted's instructions) vs. pulling from outside directly. Although the outside air may be dry, wherever cold meets warm you will have condensate....and this will either drip and run somewhere or pool and collect. Both will cause mold over time. That's where an EVHR comes in to do fresh air exchanges with the outside without actually venting directly to the outside.

I just don't understand why they can't zone out the theater with mechanical dampers and be done with it. It could be programmed to NOT put heat into the theater by keeping the dampers closed and opened when you are either cooling or wanting to force ventilate with the HVAC system. This seems simple and straight-forward to me.
post #255 of 597
Thread Starter 
Tim-

Yes that is correct. Three floors, two separate units. One unit for the top floor and the 1st floor and basement share the second unit. No dampers are currently installed anywhere throughout the house. The plan is to install dampers in the two supplies feeding the HT and adding a DV to pull air into the HT when it gets too hot in winter. I originally wanted to pull air from the adjacent room like you mentioned above but when talking to the HVAC guy he was convinced that the air from the adjacent room would not be cold enough to make any kind of an impact. He noted if for example the HT was at 78 degrees and the adjacent room was a 68 degrees then the DV would not be able to pull enough of that 68 degree air into the HT to make a discernible difference. So the change would be to pull outside air. But I dont think he thought about moisture and I am always concerned about moisture in a bellow grade room.

What are your thoughts on this? The dampers and DV would be controlled via controller/thermostat. I do believe that if the dampers shut on the supplies and I was pulling 68 degree air from another room, that coupled with my return I would think would be sufficient.
post #256 of 597
Your HVAC tech is right and wrong. The human body will produce about 250 BTU while sleeping, about 400 BTU at idle, 650 BTU doing light work, and 2400 BTU with heavy work / exercise. The typical cooling temperature from a forced-air HVAC system is in the 52 to 56 degree range. Assuming there is no equipment on in the room and there is nobody in the theater, the room will eventually match the ambient temperature of the room next door if you used pure ventilating dead-vents. However, even just one person at idle and the exhaust output of a typical projector (if the exhaust is released into the room) will overwhelm an independent ventilation-only dead vent system which is why I personally don't like them. Having more people will make the problem worse, of course. Another reason NOT to do separate dead vents is because you will have full-fledged supply and returns through the forced-air HVAC system which will allow you to ventilate with ambient air through the HVAC system. You could then have the system's fan on 100% of the time and have the dampers closed when the upstairs calls for heat.

As for cooling, I have never heard of direct ventilation from the outside - ever. Why couldn't he advise slight modification to your outdoor condensing unit (if needed) for running in low ambient conditions. I think the refrigerants boil at something like minus 60 degrees Fahrenheit, so even if it was 10 degrees outside you are 50 degrees above the boiling temp of the refrigerant. This will obviously involve a few more dampers to prevent the cool air from going upstairs, but it also cannot be 100% dedicated for the HVAC system as the amount of CFM your system can produce cannot be accommodated by just the two 6" supplies going to the room. You also must have a minimum CFM moving across the A-frame coils to keep them warm enough to prevent them from icing over.

If you think about the size of supply you would need from outside to cool your room, just look at your return - I'll bet you he spec's something like an 8" feed or a single 6" at minimum. That's a HUGE opening to the outside and you will have all kinds of critters, dust and condensate. I can't believe he would even suggest direct ventilation from the outside IMHO.
post #257 of 597
Thread Starter 
As it sounds, obviously outside ventilation is bad. How about this: the dampers will close every time the first floor calls for heat and the DV fan will pull air from the adjacent room every time the HT gets above X degrees. Do you believe this is a viable solution for the few short months its really cold? To start adding dampers to the rest of the zone, which is pretty much making another zone I will probably be getting into a fairly large cost.
post #258 of 597
As I said above, you could simply use the HVAC system's fan to ventilate the room using ambient temperature air. Why use a separate dead vent and fan when you have the forced air system already on-tap. Just have the supply dampers close if heat is called for. The HVAC fan is very cheap to run the fan from an electric bill perspective.
post #259 of 597
Thread Starter 
I understand that. But if the rest of the zone is calling for heating (i.e. First Floor) how can the fan blow ambient air to just the theater? I guess what I mean is if heat is being pushed to every other room on the zone how will the HT receive anything other than heat or nothing at all (dampers closed).
Quote:
Just have the supply dampers close if heat is called for

If heat is called and the dampers are closed than the HT will not be receiving anything.
post #260 of 597
Right. Nothing only during the time the rest of the house is receiving heat. Given a normal cycle time of 10-12 minutes 2 or 3 times per hour, about half the time the theater would not be receiving heating supply with the dampers closed. The remaining time it will be ventilating with the dampers open.

Anything you do without investing in the system will be a sub-optimal work-around, but livable.
post #261 of 597
Thread Starter 
Ok, make sense. So I just need to control the fan (to ventilate the HT when the heat is not on) and dampers for the two supplies. This sounds good, now to figure out the equipment that I need.

Besides the dampers, thermostat, temp sensor, I would think that I would need a zone controller or some type of relay. ????
post #262 of 597
Thread Starter 
On another note.... I mentioned this before but here it is again. Instead of building a rather large deep speaker backer box for the rear of the theater (for a 2nd sub) I decided to make part of the riser an IB. No specifics yet, Bpape will be assisting completely on this one as I have zero experience with IB's.
post #263 of 597
Quote:
Originally Posted by fax6202 View Post

Ok, make sense. So I just need to control the fan (to ventilate the HT when the heat is not on) and dampers for the two supplies. This sounds good, now to figure out the equipment that I need.
Besides the dampers, thermostat, temp sensor, I would think that I would need a zone controller or some type of relay. ????

That's where the communicating thermostat comes into play which will integrate with your control system. The HVAC guy will spec the zone controller for automated control of the dampers. All you should be concerned with is with thermostat control through your control system, that's it.
post #264 of 597
Thread Starter 
Considering that I have dedicated HVACs for each zone instead of a damper controlled zone system i would think that my HVAC does not have a zone controller already. Is this correct?
post #265 of 597
Correct. The HVAC guy you hired should be spec'ing all the necessary hardware you require to make it work with your system. Did you contact either of the two online companies I sent you?
post #266 of 597
Thread Starter 
Yes, the one company I called was after hours they have a call back system so I expect to hear from them tomorrow. The other was just a resale store did not provide any tech support. This will be my first resource of course. I will contact the HVAC guy tomorrow as well. Thanks.
post #267 of 597
Dave, I was away from my computer for a few days, so I dropped out of the discussions. I agree that untempered outdoor air would be a bad idea to dump into your room for the reasons already stated.

As you have realized by now, its kind of hard to retrofit an existing furnace to do what you want. By the time you spend the money to make it work correctly, you could have just bought a separate unit for the theater.

This is probably why you see most people do one of two things:
1. Install a split sytem (cheaper than a new furnace system)
2. Use inline fans and recirculate tempered air from the adjacent space.

For my room I went with a ductless split system, and I am pretty happy with the results. For $700 it was an affordable option for me (I installed the unit myself and had a buddy help me pull a vacuum and start it up). If I were to do it again, I would probably do a ducted split system (purely for asthetics).




If you do inline fans tied into the supply and return air mains the problem you run into is getting the correct amount of airflow required - this will vary depending on the season:
-in the summer, you are supplying about 57 degree supply air (so you would need 100 CFM)
-in the winter, the condensing unit is not cooling so you would be providing 70? degree air (so you would need 500 CFM)

I am totally guessing on those airflows, but guessing you would need 5 times the airflow when not cooling the air (calculations would be required). You would also still need to keep heated air out of the room in the winter, so controls would still be required (dampers to block hot air from entering and to turn off the inline fans).

If it were me, and I didnt want to do a split system to save money, I would probably do inline fan(s) with dead vents pulling air from a conditioned space and blowing the air back to a conditioned space. It would be nice to maximize the distance between where you getting the air from, and where you are putting it back. This option allows you to size your inline fans once because the airflow requirements stay about the same (the conditioned space temp is usually around 70 degrees). You will have to calculate the required CFM based on what temperature you want the theater room, and what temperature the rest of the basement is at. Once you get that CFM, you can size your exhaust fan/supply grilles/return grilles/ductwork.
post #268 of 597
Thread Starter 
I have a return that will be exhausting back into the HVAC. Wouldnt this work as well. If that is the case than having a dead vent to pull from a conditioned space and having the dampers close on the supplies; only when the zone is calling for heating...is that what you are getting at?
post #269 of 597
Quote:
Originally Posted by fax6202 View Post

I have a return that will be exhausting back into the HVAC. Wouldnt this work as well. If that is the case than having a dead vent to pull from a conditioned space and having the dampers close on the supplies; only when the zone is calling for heating...is that what you are getting at?

I need you to clarify your question. If you tie the return back into the HVAC system, where are you planning to pull supply air from? The supply air main, or the tempered adjacent room air?
post #270 of 597
Thread Starter 
The adjacent room only when 'heat' is called for that zone (thermostat for the zone is on the first floor)
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