Installation/Use/Maintenance Instructions
Fan coil units VFC, installation in sills
E
LTG Incorporated · PO Box 2889 · Spartanburg, S.C. 29304, USA
VFC_USA_BA (07/19)
Phone 864 599-6340, Fax -6344 · e-mail: [email protected] · Internet: www.LTG-INC.net
Former editions are invalid · Subject to technical modifications
page 26 of 19
4.6
Caloric output data
Caloric output data were determined at a test stand in the
LTG test lab.
Data are valid if the following applies:
- unit at operating temperature, steady-state condition
- steady-state condition during measurements
- no condensation at the heat exchanger in the cooling
mode
- water without additives (drinking water quality) *
- water supply temperatures from 53.6…61 °F in the cool
ing mode and 122…140 °F in the heating mode.
Parameters used:
- specific heat capacity of the water
1 BTU/lb/°F
- specific heat capacity of the air
0.74 BTU/lb/°F
- air density
0.075 lb/Ft
3
To ensure easy transferability, the specific caloric outputs
- i.e. the absolute caloric outputs in relation to the temper
ature difference between water intake and air entering the
heat exchanger - are given with varying fan speeds.
The outputs given in the chart do apply with specific nomi
nal flow rates only. These are stated for each type and size.
The correction charts give a graphic illustration of how
outputs change with other flow rates compared to nomi
nal flow rate output.
Flow rates have been determined through calculation and
may vary by about 10 %.
*
Addition of ethylene glycol to lower the freezing
point:
To lower the freezing point, cooling water is often
added some ethylene glycol. The lower specific ther-
mal capacity of the mixture reduces the unit's cool-
ing capacity.
4.7
Acoustic data
Acoustic data have been determined in a reverberation
chamber in the LTG test lab.
The technical data sheet contain the A weighted sound
pressure levels L
A18
for different fan speed.
Sound pressure levels apply to a room absorption surface
of 194 ft
2
which equals a room absorption of about 6
dB(A). Thus, sound power levels may easily be calculated.
L
WA
= L
A18
+ 6 dB(A)
The data given apply to one unit, i.e. one room axle. If more
than one unit is installed in the same room, the sound
pressure level will rise accordingly.
Increase in sound level with several sound sources of the
same type:
Number of sound sources
of the same type
1
2
3
4
Sound level increase [dB]
3
5
6
Measuring accuracy is ± 10%.
4.8
Hydraulic data
Heat exchangers are approved for an operating pressure
of 145 psi max. (test pressure 232 psi).
Pressures exceeding 145 psi require the express permis
sion of LTG.
Water-side pressure losses have been measured directly
at the heat exchanger connections. Further resistances
will have to be added.
Measuring accuracy is ± 10 %.
