Series
Fan-Powered
CONFIDENTIAL DOCUMENT. FOR INTERAL USE ONLY. 39VAV-SLM005-EN
Analog Controls
Analog controls are a reduced cost solution for the end-user… or are they? Analog
VAV controllers have a similar cost as DDC VAV controllers. What they lack is the
ability to:
Monitor remotely
Provide diagnostic data
Provide feedback to building control panel
DDC systems can recognize something is broken before it is even noticed by the
occupants. By the time occupants notice, a service technician can already be on the
way.
Leverage energy saving strategies such as static pressure optimization (required by
ASHRAE 90.1) or Ventilation Reset. (See http://www.trane.com/commercial/issues/iaq/
ashrae.asp.com for additional details)
Acoustics
Make sure you are doing an “apples to apples” comparison. Don’t let the competition
use a less stringent sound power assumption or show cooling only information if re-
heat is to be used.
Sound Power
–if specifying a particular spectrum shape for a particular
manufacturer, this is the same as being a proprietary specification. This is not
advised.
NC (Noise Criteria)
–NC level is determined by taking the sound power generated
using ARI 880-98, and applying a transfer function. The Transfer function assumptions
in ARI 885-98 standard are significantly different than the 90 standard. On average, the
same unit, operating at the same conditions will show a 4 NC improvement if the
older, superceded 90 standard is used. Don’t let the competition catch you in this trap.
Said another way, if your customers specified NC 40 in the space prior to the 98
standard being written, that is now equivalent to NC 44 with the current standard.
ARI Certification
Are the units that are specified ARI certified?
Titus has a quantity of 21 Valve/Fan combinations. However on the ARI web site, only
six are listed as certified units.
Nailor has a total 15 Valve/Fan combinations listed in their catalog. However, on the
ARI web site only 14 of those are listed as certified units.
Trane has a quantity of 19 Valve/Fan combinations. On the ARI web site, all 19 are
listed as certified units.
If sound is going to be critical on specific units, make sure the units that we are
comparing to are listed on the ARI website (
www.ariprimenet.org).
UL Rating for Electric Heat
Our units have been tested, approved, and listed with UL as an entire assembly. Most
VAV manufacturing companies have their units ETL listed in accordance with UL
standards.
UL never certifies a product until it passes all the standard requirements and a very
stringent internal review process. The checks and balances system that UL has
always implemented tends to cause delays to which manufacturers are very averse.
In addition, UL has a very comprehensive follow-up program to ensure that products
made after certification continue to be manufactured consistently with the initially
certified and tested product. ETL, on the other hand, is known within the test and
measurement community to be less rigorous in both the certification and the follow-
up of the products that they evaluate.
In short, the ETL Listed Mark indicates that your product has been tested by ITS ETL
SEMKO, found in compliance with accepted national standards, and meets the
Feature
Evaluation
