A/C Contractor

  • Thread starter Thread starter Michael Jones
  • Start date Start date
Michael Jones

Michael Jones

New member
The contractor I was willing to award the bid to hasn't showed up or returned my calls in about 2 weeks now. SO, needless to say, he's out.

I'm kind of glad actually, because I met with another contractor today.
This guy sounds like he really knows his stuff, and he was very enthusiastic about the project.
I'll have a bid from him on monday.

He was talking about the need to have a low velocity system, and mentioned the idea of placing baffles, and bends, and offsets in the duct work to help reduce velocity of air flow - all this on his own, without me having to bring it up. That was encouraging!

He talked about all the items necessary for a quiet system - the same ideas we kick around here on the BBS. Again, all on his own, with no prompting from me!
So... cool!

He also asked me if I'd like to have different temperature zones.

I'd hate to freeze in the CR and have people burning up hot in the live room. But I had always thought the only way to do that was to have actual, physically separate units - one for each zone.

Well, apparently there have been some technological advances in HVAC. :)
I could have different thermostats in EACH room, and still have only one unit.

As the ducting for the studio has independent ducts for each room - both supply and return - what's available now is like an electric valve - a louver - inside the duct, that will open or close that supply duct according to the temperature that room is set at!
Now, the ducts have to be over-sized for this system, but we're already doing that.

He gave me a brochure that has a nice little rendered 3D drawing of it. I'll scan it and post it here. It's pretty cool! We'll see what it comes in at on monday.
 
Congrats, Michael - sounds like you've found a contractor that actually knows what a studio is, think twice before you blow him off :=)

BTW, your AC load will actually most likely be greater in the CR, what with the extra electronics stuff - specially if you're into "toobs" - Unless you get into video shoots, in which case the lights will warm things up a lot. Either way, separate zones is for sure the way to go... Steve
 
He's taken all that into account.
Plus the lighting, and even people.

Here's that zone control system. I'll have to see what this comes in at. I have a feeeling it could be cost prohibitive. Still.... It would be nice.
 

Attachments

  • ac2.webp
    ac2.webp
    45 KB · Views: 174
Oh, I'm not looking at the "energy recovery ventilator" (what ever the heck that is) or the "high efficency air cleaner".

But see on the green, yellow and grey supply lines there's dampers that will open or close relative to the room's settings.
Pretty slick!
 
Yeah, as long as those dampers are close to the air handler and not to the studio rooms - "energy recovery ventilator" sounds and looks like some sort of heat exchanger, that may improve efficiency somewhat.

As to the "high efficiency air cleaner", you might wanna check on that. If it's a HEPA equivalent, could keep your gear noticeably less dusty (speaking of which, has your man mentioned maintaining a slight positive pressure in your rooms so that opened doors let dust OUT instead of sucking it IN? You don't want MUCH differential though - too much and door seals start to "whistle" - gotta be careful there... Steve
 
Looks like a great system.

I love the fact that it has seperate cooling coils for each space.

Be certain to provide plenty of fresh air intake just prior to the cooling coils.


Rod
 
knightfly said:
Yeah, as long as those dampers are close to the air handler and not to the studio rooms - "energy recovery ventilator" sounds and looks like some sort of heat exchanger, that may improve efficiency somewhat.

As to the "high efficiency air cleaner", you might wanna check on that. If it's a HEPA equivalent, could keep your gear noticeably less dusty (speaking of which, has your man mentioned maintaining a slight positive pressure in your rooms so that opened doors let dust OUT instead of sucking it IN? You don't want MUCH differential though - too much and door seals start to "whistle" - gotta be careful there... Steve
Click to expand...
The dampers would be right at the unit in the mechanical room, or in the plennum right above it.
It would be nice to have the special air filter, but, you know, you gotta draw the line somewhere.
ANY system is positive pressure as long as the unit is blowing. Right?

Rod -
I'm not sure where the fresh air intake is going to happen. Probably right at the air handler with a penetration through the roof or sidewall?
I'm not sure though. I'll find out.
 
"ANY system is positive pressure as long as the unit is blowing. Right?" -

Only if the system is balanced correctly, and return air isn't set up stronger than supply air - but from the sound of it, your man will most likely be on top of that too... Steve
 
knightfly said:
"ANY system is positive pressure as long as the unit is blowing. Right?" -

Only if the system is balanced correctly, and return air isn't set up stronger than supply air - but from the sound of it, your man will most likely be on top of that too... Steve
Click to expand...

Actually - any system can be set up as either positive or negative pressure.

Your contractor sounds pretty sharp, however it's still up to you to make certain he understands ALL of your needs.

When it comes to the fresh air he has to provide it - he also has to provide a means of letting some air back into the atmosphere - otherwise you will pressurize the room to the point where you can no longer pull fresh air into it.

So be certain he takes care of both.

Rod
 
Michael, there are many ways to create a low velocity system for low noise, cooling, etc.... Putting in baffles into the ducts and running oversized ducts will NOT create a positive pressure environment, unless the return is insanely small. In this case, you have an inproperly designed duct system that could cause airflow problems (or even cause unit failure). I would be careful here. The idea is good, but is it as good as his actual work? In situations like these (improper ducting), the typical fix is to put a stronger motor inline, but then you are back at square one again.....

Let me just throw something at you here...

You can actually use a multi-velocity system (i.e. velocity control built into your furnace), and in my mind eliminate most of the baffling needed. This technology is called variable speed. They put DC motors in the furnaces. These are slow ramping motors with electronic control, and EXTREMELY quiet with proper duct design. I mean quiet in the sense of, "you won't even know its on" quiet. Just a thought, if your contractor hasn't even mentioned variable speed, he isn't as technologically advanced as you think :)

And yes, variable speed costs more than a standard motor, but it would be less than the cost of custom ductwork throughout.

Zoning is definately a good thing, energy-wise too. But zoning controls can be a nightmare and are not cheap...as I'm sure you wil find out. If there is only one or two rooms you that you want to temperature control, you can run the same kind of bypass system using a more "manual" approach. That's all I got! good luck!

- RichHead
 
Thanks for the insight Rich.
We did talk about varible speed motors. The very first estimate I had, from the largest and most expensive A/C company in town, included them.

He's going to present his proposal on Friday. I'll let you all know where it comes in at.

1200 sq.ft.
Oversized ducts
Zone Control
Isolation
Baffles
All Electric A/C and Heat.

I hope its under $8000. :(
$6000 would be better.

Anyone else ever put Central A/C in a studio?
How much was it?
 
Last edited:
What I find interesting about the proposed system is that it is based around a furnace. Now Michael is in Austin TX where the main problem is cooling, not heating.

Austin I imagine is more like our Australian cities where it doesn't usually get below 0 degrees and the systems we use are refrigerator type systems that are designed to cool and we reverse it to heat. There are no furnaces in the system.

cheers
john
 
Well, above the furnace heating elements are the cooling coils. So the air blows through both. If the heating elements aren't on it doesn't get hot. Instead the air passes through the cooling coils.
The compressor for the A/C is located outside because they are so big.

Here's a pic of my home system:
The grey box is the "furnace" but it also houses the blower or fan motor - "squirrel cage" type.

The "box" above the furnace - the one with the silver tape around it is the cooling coils.
Ducting is above that... though not visible in the picture.
 

Attachments

  • ac1.webp
    ac1.webp
    27.1 KB · Views: 104
Outside is the compressor.
This one for the house is about a 4 foot cube....
Too big to house inside. Plus it needs air to draw through the coils to cool the system down.

Pretty typical system for a residence.
So when you say its "based around a furnace". its not really. Its just that typically, the blower or air handler, furnace, and cooling coils are all integrated into a single housing.
 

Attachments

  • ac2.webp
    ac2.webp
    34.7 KB · Views: 100
Now, John, when you say you reverse it to heat - that sounds to me like what we call a heat pump.

For whatever reason, those aren't very popular here. Maybe its too humid? I don't know for sure, but you simply don't see many of them here.
 
Yeah, thats a heat pump. Heat pumps are usually used in palces where either gas is not a heating option, or there are very low heating requirements (outdoor air temperatures in 20-40 degrees F). Heat pump is an all electric option...

- RichHead
 
OK - we call them reverse cycle airconditioning. Like your the compressor is outside and pipes deliver the heating/cooling to a blower box in the ceiling. Here are the three blower boxes for left bank:
 

Attachments

  • up2_9.webp
    up2_9.webp
    10.1 KB · Views: 78
Yes Michael -it's a heat pump.

pic4.gif


YOu must remember that the studio is totally insulated - over insulated by normal terms so loss is minimum. I'd suspect that in your climate the cooling is the major use and it does eliminate the need for supplying gas lines for heating.

It's basically a reversable refrigerator :) These units are used throughout australia. We rarely have a gas/oil driven units.

cheers
John
 
You must log in or register to reply here.
Back
Top