Carrier AQUAZONE 50RHC006-060 Series Product Data page 38

Application data (cont)
Acoustical design
Sound power levels represent the sound produced by the
source, the WSHP unit, with no regard to attenuation be-
tween the source and the space. Acoustical design goals
are necessary to provide criteria for occupied spaces.
These goals help ensure that people are comfortable and
can communicate effectively over the air conditioning sys-
tem and other background noise sources.
Acoustical design goals are desirable sound pressure lev-
els within a given conditioned space and are represented
by Noise Criteria (NC) curves. Noise Criteria (NC) curve
levels represent a peak over a full spectrum of frequencies.
A high value in a low frequency band has the same effect
on NC level as a lower value in a high frequency band. It is
important that sound levels be balanced over the entire
spectrum relative to the NC curve. The lower the NC crite-
ria curve, the more stringent the room acoustical design
must be to meet the design goals.
It is important to know how to convert the unit ratings
from sound power (Lw) to sound pressure (Lp). This
conversion depends on the specifics of the installation's
acoustic environment.
Assessing an area's acoustical design means comparing
the sound pressure (Lp) with the NC curve for the selected
area.
Some of the factors that affect conversion of sound
power to sound pressure and consequent NC level include:
• Type of acoustical ceiling
• 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
NC-20 52 41 33
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
38
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
Modulating reheat option
The modulating reheat option diverts condenser water
through a water-to-air coil that is placed after the evapora-
tor coil. The modulating reheat valve automatically adjusts
reheat capacity based upon leaving air temperature and
loop entering water temperature to provide 100% reheat
and neutral supply air to the space.
NOTE: The modulating reheat option is only available on
50RVC018-036 and 50RVC042-060 units.
The modulating reheat option can be applied to a num-
ber of common applications, such as:
• classrooms
• condominiums
• apartments
• computer rooms
• high latent load spaces, such as auditoriums, theaters,
and convention centers
• indoor swimming pool space conditioning
• humid climates
Equipment selection — If the unit will be used for space
cooling, a unit with at least enough capacity to satisfy the
building sensible load should be selected. If the latent cool-
ing load is not satisfied by the selection, a larger unit with
enough latent capacity will be required. If the unit will be
used for dehumidification purposes only, the latent capac-
ity is the only necessary consideration.
NOTE: In some cases, the high static option may be re-
quired for applications with higher static ductwork, as the
reheat coil adds a small amount of resistance to the air
stream.
50RVC LATENT CAPACITY AT 85 F (29.4 C) EWT
50RVC
UNIT SIZE
018
024
030
036
042
048
8000
060
11
16
Sound control
21
Analyzing the projected sound level in the conditioned
27
space caused by a WSHP unit located in a ceiling plenum is
32
quite involved. The key is to have good sound power
37
ratings (Lw) in dB on the equipment to determine the
42
sound attenuation effect of the ductwork, ceiling and room.
47
Aquazone™ equipment includes standard attenuating fea-
52
tures and offers an advanced mute package. In addition,
57
Carrier provides suggestions for unit sound design around
62
the WSHP.
MOISTURE
LATENT
REMOVAL
CAPACITY
(MBtuh)
(lb/hr) (kg/hr)
4.7 7.7
6.1 5.7
6.8 6.4
9.6 9.0
11.0 10.3
12.7 11.9
15.2 14.2
POWER
(kW)
2.0 1.4
2.6 1.8
2.9 2.0
4.1 2.8
4.7 3.2
5.4 3.7
6.4 4.5