Specifications

82
ENVISION COMMERCIAL SPECIFICATION CATALOG
Engineering Guide Specications
General
Furnish and install WaterFurnace Water Source Heat Pumps, as
indicated on the plans. Equipment shall be completely assem-
bled, piped and internally wired. Capacities and characteristics
as listed in the schedule and the specifications that follow. The
reverse cycle heating/cooling units shall be either suspended
type with horizontal air inlet and discharge or floor mounted
type with horizontal air inlet and vertical upflow/downflow air
discharge. Units shall be AHRI/ISO 13256-1 certified and listed
by a nationally recognized safety-testing laboratory or agency,
such as ETL Testing Laboratory. Each unit shall be computer
run-tested at the factory with conditioned water and operation
verified to catalog data. Each unit shall be mounted on a pallet
and shipped in a corrugated box or stretch-wrapped. The units
shall be designed to operate with entering liquid temperature
between 20°F and 120°F [-6.7°C and 48.9°C].
Casing and Cabinet
The cabinet shall be fabricated from heavy-gauge galvanized
steel and finished with corrosion-resistant powder coating. This
corrosion protection system shall meet the stringent 1000 hour
salt spray test per ASTM B117. The interior shall be insulated
with 1/2˝ thick, multi-density, cleanable aluminum foil coated
glass fiber with edges sealed or tucked under flanges to prevent
the introduction of glass fibers into the discharge air. Standard
cabinet panel insulation must meet NFPA 90A requirements, air
erosion and mold growth limits of UL-181, stringent fungal resis-
tance test per ASTM-C1071 and ASTM G21, and shall meet zero
level bacteria growth per ASTM G22. Unit insulation must meet
these stringent requirements or unit(s) will not be accepted.
One (horizontal) to two (vertical) blower and three compressor
compartment access panels shall be ‘lift-out’ removable with
supply and return ductwork in place..
A duct collar shall be provided on the supply air opening. Stan-
dard size 1 in. [2.5 cm] MERV 8 pleated filters shall be provided
with each unit. Units shall have a return air filter rack/duct
collar that Is field convertible from 1 in. [2.5 cm] to 2 in. [5.1 cm].
The upflow vertical units shall have a removable insulated divid-
er panel between the air handling section and the compressor
section to minimize the transmission of compressor noise and
to permit operational service testing without air bypass. Vertical
units shall be supplied with left or right horizontal air inlet and
top vertical air discharge. Horizontal units shall be supplied
with left or right air inlet and side or end air discharge.
The compressor shall be double isolation mounted using select-
ed durometer grommets to provide vibration free compressor
mounting. The compressor mounting bracket shall be acousti-
cally deadened galvanized steel to prevent vibration transmis-
sion to the cabinet.
Option: MERV 13 Filter - A 2" [5.1 cm] wide MERV 13 filter shall
be installed in filter rack for high efficiency filter applications.
Option: A Super Quiet Sound package shall include multi-
density full coverage compressor blanket and sound deadening
multi-density laminated metal plate under the compressor.
Option: An internally mounted low pressure drop (high Cv)
water solenoid valve shall be factory installed for use in variable
speed pumping applications.
Option: An internally mounted low wattage circulating pump
shall be factory installed for use in primary/secondary or load
match pumping systems.
The drain pan shall be of plastic construction to inhibit cor-
rosion inhibit bacterial growth. Drain outlet shall be located
on pan as to allow complete and unobstructed drainage of
condensate. The unit as standard will be supplied with solid-
state electronic condensate overflow protection. Mechanical
float switches WILL NOT be accepted. Vertical units shall be
furnished with a PVC slip condensate drain connection and an
internal factory installed condensate trap. Horizontal units shall
have a pipe drain connection suitable for standard 3/4" PVC
glue fittings.
Option: Stainless steel drain pan shall be factory installed.
Refrigerant Circuit
All units shall utilize the non-ozone depleting and low global
warming potential refrigerant R410A. All units shall contain
a sealed refrigerant circuit including a hermetic motor-com-
pressor, bidirectional thermostatic expansion valve, finned tube
air-to-refrigerant heat exchanger, reversing valve, coaxial tube
water-to-refrigerant heat exchanger, optional hot water genera-
tor coil, and service ports.
Compressors shall be high-efficiency single speed rotary or
scroll, or dual capacity scroll type designed for heat pump duty
and mounted on vibration isolators. The compressor shall be
double isolation mounted using selected durometer grommets
to provide vibration free compressor mounting. The compres-
sor mounting bracket shall be acoustically deadened galvanized
steel to prevent vibration transmission to the cabinet. Compres-
sor motors shall be single-phase PSC with overload protection.
The air coil shall be sized for low-face velocity and constructed
of lanced aluminum fins bonded to rifled copper tubes in a
staggered pattern not less than three rows deep for enhanced
performance.
Option: FormiShield electro-coated air coil for maximum pro-
tection against formicary corrosion.
The coaxial water-to-refrigerant heat exchanger shall be
designed for low water pressure drop and constructed of a
convoluted copper (cupronickel option) inner tube and a steel
outer tube. Refrigerant to air heat exchangers shall utilize en-
hanced corrugated lanced aluminum fins and rifled copper tube
construction rated to withstand 600 PSIG (4135 kPa) refriger-
ant working pressure. Refrigerant to water heat exchangers
shall be of copper inner water tube and steel refrigerant outer
tube design, rated to withstand 600 PSIG (4135 kPa) working
refrigerant pressure and 450 PSIG (3101 kPa) working water
pressure. The thermostatic expansion valve shall provide proper
superheat over the entire liquid temperature range with minimal
“hunting.” The valve shall operate bidirectionally without the
use of check valves.
Option: Cupronickel refrigerant to water heat exchanger shall
be of copper-nickel inner water tube and steel refrigerant outer
tube design, rated to withstand 600 PSIG (4135 kPa) working
refrigerant pressure and 450 PSIG (3101 kPa) working water
pressure. Water lines shall also be of cupronickel construction.
Option: Hot water generator - Internal double wall vented hot
water generator coil refrigerant to water heat exchangers shall
be of copper inner water tube and steel refrigerant outer tube
design, rated to withstand 600 PSIG (4135 kPa) working refrig-
erant pressure and 450 PSIG (3101 kPa) working water pressure.
Option: ThermaShield coated water-to-refrigerant heat
exchanger, water lines and refrigerant suction lines shall be
insulated to prevent condensation at low liquid temperatures
below 50°F.