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 40 of 19
5.3
Condensate Connection
Remove the condensate drainage plugs
before connecting the condensate lines!
Condensate formation occurs when the cold water supply
temperature is below the ambient air dew point tempera
ture. Neither LTG Induction Units nor LTG Fan Coil Units
have been designed for an operation with steady conden
sate formation which is why special care must be taken
for the water inlet temperature not to fall below the dew
point temperature. If necessary, provide a continuous con
trol of the water temperature based on outside air humid
ity. As an option, LTG provides a special insulated version
for condensing operation (please consider when design
ing and ordering).
In any case, please observe the following:
Air conditioning plant with centralized cooling and de
humidification
(water temperature > 55.4 °F)
A certain water supply temperature will result in con
densate formation since the temperature is below the
ambient air dew point. This dew point, however, de
pends on indoor air humidity. The water supply temper
ature may be 1…3 °F below the dew point of the air since
the air temperature on the pipes is higher than the ac
tual water temperature.
If rooms are ventilated with a maximum supply air
humidity of i.e. 60 grains/lb the water supply tempera
ture may be lowered to 59 °F without risk of condensate
formation.
In case of an increased humidity of the air, there a two
solutions:
Case A: Condensate tray not connected
(condensate socket closed by plug)
- If outside air humidity is high keep windows closed.
- Alternative:
If windows are opened use a window contact with
closing/time-delayed opening system.
- Alternative:
A central system controls the water supply tempera
ture based on the outside air humidity whenever win
dows are opened, i.e. in case of a high humidity of the
air the water supply temperature is increased. This
will, however, reduce the cooling capacity.
Case B: Condensate tray connected
- No need for a window contact or central cold water
supply temperature raise in case of high outside air
humidity.
- If a short-term increase of the room air humidity is
probable it is recommended to provide the tray with a
thermal insulation.
- All codes, rules and regulation requirements are to be
met with the installation of any condensate drain con
nection on site.
Ventilation without dehumidification or window
opening (water temperature > 61 °F)
In case of a ventilation without dehumidification the wa
ter supply temperature must be 61 °F or up.
If the supply air is not dehumidified or the ventilation is
realized by opening windows, the air humidity might be
very high which is why the following case will have to be
considered:
The condensate tray must be connected.
- A central cold water control and weather related cold
water supply temperature raise is recommended
since opening the windows might result in outside air
with a high humidity entering the room and the tem
perature dropping below the air's dew point.
Whatever the case of application, all
water carrying pipes and fittings
outside the condensate tray's range
must be insulated.
If a condensate drainage system is
connected there must be sufficient
slope and proper drainage of the
condensate
produced.
Condensate
trays and the condensate drainage
system require cleaning and sanitation
checks on a regular basis.
