Sterling HS - Manual (Page 9)

9
CORRECTIONS WHEN USING GLYCOL SOLUTION IN SYSTEM
TECHNICAL DATA
SOUND RATING
I
II
III
IV
V
III - VII*
CATEGORY OF AREA
Apartment, assembly hall, classrooms
churches, courtrooms, executive offi ces,
hospitals, libraries, museums, theatres.
Dining rooms, general offi ces, recreation
areas, small retail stores.
Restaurants, banks, cafeterias, depart-
ment stores, public buildings, service
stations.
Gymnasiums, health clubs,
laundromats, supermarkets.
Garages, small machine shops, light
manufacturing.
Factories, foundries, steel mills.
* Depending on specifi c use in these
facilities, size of operation, etc.
TECHNICAL DATA
Propylene
Glycol
1. Heat transfer 20% solution .97*
@180°F (82°C) with
no increase in fl ow rate 50% solution .90*
2. G.P.M. Req’d.
@180°F (82°C), 20°F (11°C) Δ t
(no correction to pump curve) 1.10%*
3. Pump Head Req’d. @180°F (82°C)
w/increase in G.P.M. 1.23%*
4. Specify gravity (water = 1.0) 1.045-1.055*
5. Pounds/Gallons @60°F (16°C) 8.77
(water = 8.3453 Pound/Gallon)
6. pH @ 50% by volume 9.5
The performance data listed in Table
6 includes sound ratings. The ratings
provide a guide in determining the
acceptable degree of loudness in particular
occupancy situations.
Certain general rules apply to specifi c
selection of unit heaters with regard to
degree of quietness (or loudness);
• The greater the fan diameter, the
higher the sound level.
• The higher the motor RPM, the higher
the sound level. Note that on most
units the lower the speed mode results
in lowering the sound rating one incre-
ment.
• Selecting a larger number of smaller
units generally results in lower overall
noise levels than fewer large units.
All horizontal steam and hot water unit
heater motors, whether fan guard or
shelf-mounted, are isolated from the
mechanical mount by resilient isolators.
This mounting along with balanced fan
blades and excellent overall construction
integrity, assures you the utmost in quiet
operation.
The following table outlines sound ratings
for various applications. The lower the
number, the quieter the unit and the lower
the sound requirement.
Propylene
Glycol
7. Freezing Point 55% by volume
-
50% -28°F (-33°C)
40% -13°F (-25°C)
30% + 4°F (-16°C)
20% +17°F (- 8°C)
*Compared to water.
Altitude Factor
Sea level - 1000 ft. (305m) 1.00
1000 ft. - 3000 ft. (915m) .958
3000 ft. - 5000 ft. (1524m) .929
5000 ft. - 7000 ft. (2134m) .900
7000 ft. - 10000 ft. (3048m) .871
Approximate factors at varying altitudes