Search:

looks like cheap junk to me. i do hope you never want to provide hot air through this thing.
there are proper ways selecting a commercial diffuser for the application.
try a company like Titus,...

while it is true that all dampers will have a resonance frequency, the reputable vav manufacturers test their units and design the dampers to have a frequency outside of the normal operating range....

it has been many years since i have seen one of these. post a couple pictures to jog my memory and i can probably help you with your problems.
what controls are on them?

as prevously stated there are lots of variables and different systems.
however 3-8 psi is very very common. 3 or lower being being full open, 8 or higher being full closed.

the unit comes with a door interlocking disconnect on the enclosure. why would you not just run direclty from the breaker to that switch?

New York is home of Carrier, can't fight VVT there, politics, jobs etc...
Carrier doesn't build a fan box.
I would also use hot water instead of electric as their electricity is expensive and they...

When you use this type of controller, direct/reverse acting and normally open/closed have no relationship to each other.
you can have any combination of the above.
it is not like just using an...

http://www.titus-hvac.com/ecatalog/getfile2.aspx?fileid=5781

they don't post the charts themselves (call Titus for copies) but you can calculate the values using the K factors on this sheet.

A vav manufacturers catalog is probably the easiest place to start.

http://www.nailor.com/onlinecatalogs/CAT-06/CAT1START.pdf

a vav box air volume has nothing to do with smoke.

the noise from the box selections will drive everyone out of the building anyway.

answer above gives you a very high torque actuator for a typical damper.

the real answer depends on the type of damper used and the manufacturer.
very low leakage dampers are tightly fitted and...

that is a very low torque for a damper that size.
if the damper twists slightly as the metal contracts in the cold the torque will increase dramatically, could be dirty bearings, moisture buildup in...

RH is no good unless we tie to a specific temperature.
Where did you get dew point info?

i tried this, they either can not or will not give me an answer.

USP 797, United States Pharmacopia is the relevent standard for pharmacy areas in the US. Also check the ashrae/aia sources above.
For bio-safety labs there are specific requirements that I think...

I am working on project for a childrens hospital new pharmacy area.
Basically the question that has arose is "what should be the humidity level in this room".
This is not as straightforward as it...

Latest standard for HVAC design is ASHRAE Standard 170-2008
Ventilation of Health Care Facilities
You should also review the relevent handbook chapters.

There is also the American Institute of...

With regards to airflow, laminar means non-aspirating or non-mixing. A laminar flow diffuser will create basically a column of air below it that does not mix appreciably with room air. Thats why they...

For the Nailor damper (or Ruskin) to meet the UL requirements the factory sleeve must be there, and have the coating intact.
You cannot mess around with that and meet their factory UL compliance,...

rip it out quick and put in fibreglass.

mechanical drawings are widthxheight
architectural drawings are heightxwidth

i have no idea why?

maxster
Great you tube link, never seen that before.

most of the bushings used on dampers are called self lubricating, meaning that they are usually oil impregnated bronze, or a type of plastic.
Now before everyone here ridicules the...

this is the best source of info. lots of good stuff but long and tedious reading.

http://www.cdc.gov/ncidod/dhqp/gl_isolation.html

in practice maintaining the pressure difference is very...

both the II and IIA are made by krueter and are essentially identical inside.
if you grab a recently failed one and take it apart (note you will never get it back together) inside you will see a...