Specifications

Catalog 1114-1 SmartSource 2-Stage Water Source Heat Pumps Page 9 of 76
Horizontal unit external
duct-mounted electric
heater
Vertical unit internal
factory-installed
electric heater
Waterside Economizer
The waterside economizer option helps to reduce energy consumption by
using cool loop water temperatures to condition a space without energiz-
ing mechanical cooling. Even in the coldest weather a space can experi-
ence a build-up of ambient heat from people, equipment, lighting and
the sun. Buildings with temperature controlled computer rooms, media/
resource rooms or medical equipment rooms, benet from the waterside
economizer when the geothermal loop eld or cooling tower temperatures
are cool enough to provide air conditioning.
Variable ow pumping systems are recommended for these systems to
further reduce energy consumption, while maintaining sufcient water
ow during economizer operation.
The waterside economizer includes a hydronic cooling coil located
upstream of the unit's evaporator coil and after the lter. When enter-
ing water temperatures are between 70° to 50°F, a 3-stage thermostat or
room temperature sensor in conjunction with a factory-installed enter-
ing water temperature sensor and a 2-position 3-way diverting valve,
determine when loop water can be diverted to the hydronic coil and the
unit coax coil for economizer cooling. Smart fan controls further reduce
energy consumption and sound levels by delivering optimum air ow
during economizer operation. The MicroTech III SmartSource controller
determines if the economizer and mechanical cooling can be activated
together, while optimizing unit airow. The controller also provides low
temperature protection to avoid economizer operation when entering
water temperatures are below 35°F.
Electric Heat (internal or external)
Factory installed electric heaters are available on vertical units. These
heaters are located above the blower housing inside the discharge air ple-
num. Horizontal units utilize an external duct-mounted electric heater for
eld-installation. Unit controls are available for boilerless, supplemental,
primary or emergency electric heat to serve several different applica-
tion needs. Boilerless electric heat will be energized when the entering
water temperature falls below set point. This will allow electric heat to
function while ensuring the compressor remains off. With supplemental
electric heat control, the wall thermostat will activate the compressor and
heater simultaneously if necessary to maintain room heating conditions.
For primary heat applications, only the electric heater will provide heat
without energizing the compressor. Emergency heat is activated by a 24V
thermostat signal to energize the external duct-mounted electric heat. For
available electric heat sizes and voltages see "Model Nomenclature"
on page 3, "Product Code Index", code item "23".
Designed-in Sound Reduction
Provided as standard, the compressor mount has a unique dual-level
vibration isolation system. The compressor is mounted on vibration
isolation grommets to a heavy gauge mounting plate, then isolated
from the cabinet base with rubber grommets to minimize vibration
transfer. The compressor is equipped with thermal overload protec-
tion and is located in a well-insulated compartment away from the
air stream to minimize sound transmission. All access panels have
acoustic seals to eliminate panel vibration and minimize radiated
sound levels. Fan noise can be minimized at low airow with eld ad-
justable ECM fan motor settings. An optional sound reduction kit adds
a 3/4" thick acoustic foam panel of insulation to the fan section and a
compressor blanket (unit sizes 026 to 072 only) to help further reduce
operating sound levels.
SmartSource Unique Features
Waterside
Economizer Coil
Waterside
Economizer Coil