# Dear TC8.6 Member,

The International Alliance for Interoperability, of which ASHRAE is a
member, is developing standard methods of describing HVAC equipment so
that data can be transferred more easily and reliably between computer
applications such as CAD, equipment sizing, cost estimation, energy
calculations etc. The aim is also to support commissioning and O&M as
computer tools become available. We are asking for your help in
reviewing the draft specification for cooling towers given below. We
would like the list of properties to be complete for the applications
mentioned and to use terminology that is both correct and commonly used.
As far as possible, we would also like to avoid duplication/redundancy.

Bob Shriver has invited me to attend your TC meeting at 2.15 on Monday,
January 29 in Atlanta to answer any questions and get comments back from
the TC. I'd be most appreciative if you would review this between now
and the 29^th^ and write comments on a printed copy that I can collect
at the meeting. If you have any questions before the 25^th^, please
email me at [PHaves@lbl.gov](mailto:Phaves@lbl.gov) or call me at
Lawrence Berkeley National Laboratory, (510) 486 6512. If you won't be
at the Atlanta meeting, please fax me your comments at (510) 486 4089,
or call me or email me.

Thanks in advance for your help,

Philip Haves,

Leader, Commercial Building Systems Group

Lawrence Berkeley National Laboratory, MS 90-3111

Berkeley, CA 94720

Tel: (510) 486 6512

Fax: (510) 486 4089

# Draft List of Properties for Cooling Towers

1/2/01

### Type (not necessarily mutually exclusive)

Open-circuit / closed-circuit

Wet / dry / combination wet-dry

Mechanical-draft / natural-draft

Induced-draft / forced-draft

Counterflow / cross-flow / parallel flow

Spray-filled / splash-type fill / film-type fill

Integral basin / field-erected

Capacity control: fan cycling / two-speed fan / variable-speed fan /
modulating dampers / modulating bypass valve / multiple series pumps /
two-speed pump / variable-speed pump

Control strategy: fixed exiting water temperature set-point / wet-bulb
reset, ...(?)

Size: height, length, width

Weight

Casing materials: wood / metal / plastic ...

Fill material:

Number of cells

Basin reserve volume (volume between operating and overflow levels)

Isolator compressibility factor

Isolator minimum static deflection

Vibration transmissibility

**Performance**

Capacity at design conditions

Design entering water temperature

Design exiting water temperature

Design wet-bulb temperature

Design water flow rate

Lift -- elevation difference

Water-side pressure drop at design flow rate

Open-circuit height difference (?) (flow-independent part of water-side
pressure drop)

Design air flow rate

Maximum allowed external air-side pressure-drop

High-speed fan motor power

Low-speed fan motor power (two-speed fans)

Minimum fractional fan speed (variable-speed fans)

Sump heater input power

Sound level (dbA at 5 ft?)

Noise class

Drift loss (fraction of water circulation rate)

Off-design performance (including performance at different airflow and
water flow rates) -- is there a standard way to represent this???

### Sequences of operation

Start-up/shut-down

Interlocks

Fan operation

Pump/valve operation

Sump heater

Condenser water

### Performance Verification Measurement Points

Water flow rate

Entering water temperature

Exiting water temperature

Ambient wet-bulb temperature

High-stage fan motor data: Volts, PH, RLA

Low-stage fan motor data: Volts, PH, RLA (two-speed fans)

VFD speed (variable speed fans)

### 

### Maintenance

Blowdown rate

Biocide type and concentration

Maintenance intervals: fan-belt, fan bearings, motor bearings, ...