Lighting Design Guide 230V
DOC. 4859
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Heat/Cool Systems
Radiant Heat systems:
Radiant heat is a form of hydronic (hot water) heat that circulates hot
water through pipes (baseboard radiation systems) or special tubing and installs on the perimeter
of the house or underneath floors.
Forced Air systems:
In a ducted heating/cooling system, a large fan (blower) forces heated air
from the furnace into the ducts and enters the rooms through a register or grill in the floor or wall.
One or Two Stages:
Unlike traditional furnaces that turn on and run at full capacity with each
demand for heating, two-stage furnaces operate like two separate furnaces. The unit begins to run
in its first stage, and operates at a fraction of its heating capacity. This reduced capacity is
sufficient on mild winter days. On very cold days, the furnace adjusts to full capacity (second
stage) to meet the demand for heat.
Heat Pump Systems
A heat pump extracts available heat from one area and transfers it to another. Even cold air
contains some heat, and heat pumps can extract heat from the outside air on a cold day and
transfer it indoors to maintain a comfortable temperature. A heat pump also works in reverse
during the summer, extracting heat from indoors and transferring it outdoors.
Dual Fuel:
A dual fuel system combines an energy-efficient air-source heat pump with a new or
existing oil, gas or propane furnace. The furnace runs in place of the heat pump in cold weather.
Aux (Auxiliary) Heat:
When the a heat pump can no longer efficiently transfer heat from the
outside air, the thermostat automatically turns on a secondary heat source, such as electric resistive
heat.
Slab Systems
Slab heating works from the ground up. The heating components are installed below the floor or
are embedded in a concrete slab. Heat radiates from the floor to warm the space above. The CHV-
TSTAT and CHV-THSTAT support seven variations of slab heat systems.
SLAB 1:
Floor warming only. Operates the slab heat to maintain a particular slab temperature.
System mode is enabled/disabled with Floor Warming Heat and OFF inputs. Slab is maintained at
the slab setpoint temperature value. Connection to the slab output relay is terminal W1.
SLAB 2:
One stage space heat with slab maximum. Maintains a particular air temperature using
the slab to heat the space. Will not heat over the slab maximum temperature even if this results in
the space being under-heated. Connection to the slab output relay is terminal W1.
SLAB 3:
One stage space heat with slab maximum and slab minimum. Performs the same
operation as SLAB 2, and also keeps the slab at least as warm as slab setpoint. This may result in
the space being overheated to maintain the slab minimum temperature. Connection to the slab
output relay is terminal W1.
SLAB 4A:
Two-stage space heat with slab maximum and one stage cool. Maintains the air
temperature using the slab for heat, up to the slab maximum. Augments the air heating by using a
second stage of heat (generally a forced air system). Allows the second stage to operate by itself
should the slab reach is maximum temperature and shut off. Cools the space with cooling call.
Intended for heat-cool type forced air systems, with relay output connections to terminal W1 for
slab, terminal W2 for 2nd stage heat, and terminal Y1 for cooling.
SLAB 4B:
Same operation as SLAB 4A, but intended for a heat pump type second stage. Relay
output connections are terminal W1 for slab heat, with heat pump-type connections on terminals
Y1/O/G for cooling and heating calls. Aux heat is on terminal W2.
SLAB 5A:
One stage space heat and cool with floor warming. Combines the operation of a space
heating/cooling thermostat with a floor-warming thermostat. Maintains the slab at slab setpoint,
and maintains the space at the heat, cool, or auto setpoints. Systems effectively operate
independently. Heat/Cool/Auto/Off sets the space control modes, and Floor Warming HEAT/OFF