Carrier 50KQA Product Data page 24

Application data (cont)
Some of the factors that affect conversion of sound
power to sound pressure and consequent NC level include:
• Acoustical ceiling type
• Use of metal or flex duct
• Absorption in the occupied space
• Location in the occupied space
• Open or closed layout plan
• Use of open or ducted returns
• Orientation of unit to occupant
• Use of lined or unlined duct
OCTAVE BAND SOUND PRESSURE LEVEL (Lp)
ASSOCIATED WITH NC CURVES
OCTAVE BAND SOUND PRESSURE LEVEL (Lp)
NOISE
CRITERIA
CURVES
63 125 250
NC-15 49 36 26
52 41 33
NC-20
NC-25 54 45 38
NC-30 58 49 41
NC-35 61 53 45
NC-40 64 57 50
NC-45 67 61 54
NC-50 71 64 58
NC-55 74 68 63
NC-60 77 71 67
NC-65 80 75 71
WSHP sound control
Analyzing the projected sound level in the conditioned
space caused by a WSHP unit is quite involved. The key is
to have good sound power ratings (Lw) in dB on the equip-
ment to determine the ductwork, ceiling and room sound
attenuation effect. We provide suggestions for console unit
sound design around the WSHP units.
Console units
With console units, the fan and compressor are located
within the space, and only the casing design attenuates the
transmission of sound sources into the space. The designer
should carefully review the manufacturer's acoustical data
when selecting console units and use lower fan speeds to
minimize space noise.
Operating limits
Environment
This equipment is designed for indoor installation ONLY.
Power supply
A voltage variation of ± 10% of nameplate utilization volt-
age is acceptable.
Starting conditions
50KQA units
The 50KQA units start and operate in an ambient temper-
ature of 40 F, with entering air temperature at 40 F, with
entering water temperature at 70 F, with both air and
water at the flow rate used in the ARI Standard 320-86
rating test, for initial start-up in winter.
24
Frequency (Hz)
500 1000 2000 4000
17 17 14 12
27 22 19 17
31 27 24 22
36 31 29 28
40 36 34 33
45 41 39 38
49 46 44 43
54 51 49 48
58 56 54 53
63 61 59 58
68 66 64 63
50KQD units
The 50KQD unit will start and operate in an ambient tem-
perature of 40 F, with entering air temperature at 40 F,
with entering water temperature at 40 F, with both air and
water at the flow rates used in the ARI Standard 320-86
rating test, for initial start-up in winter.
NOTE: These are not normal or continuous operating
conditions. We assume that such a start-up is used to bring
the building space up to occupancy temperature.
Min. Ambient Air
Rated Ambient Air
8000
Max. Ambient Air
11
Min. Entering Air
16
Rated Entering Air, db/wb
21
Max. Entering Air, db/wb
27
32
37
42
47
Min. Entering Water
52
Normal Entering Water
57
Max. Entering Water
62
LEGEND
db — Dry Bulb
wb — Wet Bulb
NOTES:
1. Minimum Air and Water conditions can only be used at ARI flow
rates.
2. Only one maximum or minimum value may be used with 50KQA
units, all other parameters must be at normal conditions. The
50KQA units may have up two values at maximum or minimum
with all other parameters at normal conditions.
Solenoid valves
In applications using variable flow pumping, solenoid
valves can be factory installed and operated from the con-
trol board in the Aquazone™ WSHP unit.
Freeze protection
Applications where systems are exposed to outdoor
temperatures below freezing (32 F) must be protected from
freezing. The most common method of protecting water
systems from freezing is adding glycol concentrations into
the water. Use design care when selecting both the type
and concentrations of glycol due to the following:
• Equipment and performance may suffer with high con-
centrations of glycol and other antifreeze solutions
• Loss of piping pressure may increase greatly, resulting
in higher pumping costs
• Higher mixture viscosity may cause excess corrosion
and wear on the entire system
• The water's acidity may be greatly increased, promoting
corrosion
Glycol promotes galvanic corrosion in systems of dissimilar
metals. The result is corrosion of one metal by the other,
causing leaks.
AIR LIMITS
50KQA
Cooling Heating Cooling
50 F 50 F 40 F
80 F 70 F 80 F
100 F 85 F 100 F
50 F 50 F 50 F
80/67 F 70 F 80/67 F
100/83 F 80 F 100/83 F
WATER LIMITS
50KQA
Cooling Heating Cooling
60 F 60 F 40 F
85 F 70 F 85 F
95 F 90 F 110 F
50KQD
Heating
40 F
70 F
85 F
40 F
70 F
80 F
50KQD
Heating
40 F
70 F
90 F