Specifications

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ENVISION COMMERCIAL SPECIFICATION CATALOG
The Closed Loop Heat Pump Concept
The basic principle of a water source heat pump is the
transfer of heat into water from the space during cooling,
or the transfer of heat from water into the space during
heating. Extremely high levels of energy efficiency are
achieved as electricity is used only to move heat, not to
produce it. Using a typical WaterFurnace Envision Series,
one unit of electricity will move four to five units of heat.
When multiple water source heat pumps are combined
on a common circulating loop, the ultimate in energy
efficiency is created: The WaterFurnace units on
cooling mode are adding heat to the loop which the
units in heating mode can absorb, thus removing heat
from the area where cooling is needed, recovering and
redistributing that heat for possible utilization elsewhere
in the system. In modern commercial structures, this
characteristic of heat recovery from core area heat
generated by lighting, office equipment, computers,
solar radiation, people or other sources, is an important
factor in the high efficiency and low operating costs of
WaterFurnace closed source heat pump systems.
In the event that a building's net heating and cooling
requirements create loop temperature extremes,
Envision Series units have the extended range capacity
and versatility to maintain a comfortable environment
for all building areas. Excess heat can be stored for
later utilization or be added or removed in one of three
ways; by ground-source heat exchanger loops: plate
heat exchangers connected to other water sources,
or conventional cooler/boiler configurations. Your
WaterFurnace representative has the expertise and
computer software to assist in determining optimum
system type for specific applications.
The Closed Loop Advantage
A properly applied water source heat pump system
offers many advantages over other systems. First costs
are low because units can be added to the loop on an
"as needed basis"- perfect for speculative buildings.
Installed costs are low since units are self-contained
and can be located adjacent to the occupied space,
requiring minimal ductwork. Maintenance can be done
on individual units without system shut-down. Conditions
remain comfortable since each unit operates separately,
allowing cooling in one area and heating in another.
Tenant spaces can be finished and added as needed.
Power billing to tenants is also convenient since each unit
can be individually metered: each pays for what each
uses. Nighttime and/or weekend uses of certain areas are
possible without heating or cooling the entire facility. A
decentralized system also means if one unit should fault,
the rest of the system will continue to operate normally,
as well as eliminating air cross-contamination problems
and expensive high pressure duct systems requiring an
inefficient electric resistance reheat mode.
The Envision Approach
There are a number of proven choices in the type of
Envision Series system which would be best for any given
application. Most often considered are:
• Closed Loop/Ground-Source Systems utilize the stable
temperatures of the earth to maintain proper water source
temperatures (via vertical or horizontal closed loop heat
exchangers) for Envision Series extended range heat
pump system. Sizes range from a single unit through many
hundreds of units. When net cooling requirements cause
closed loop water temperatures to rise, heat is dissipated
into the cooler earth through buried high strength plastic
pipe "heat exchangers." Conversely if net space heating
demands cause loop heat absorption beyond that heat
recovered from building core areas, the loop temperature
will fall causing heat to be extracted from the earth. Due
to the extended loop temperatures, AHRI/ISO 13256-1
Ground Loop Heat Pumps are required for this application.
Envision Application Notes
Supply Water
Return Water
Pumps
Envision
Unit
Envision
Unit
Envision
Unit
Envision
Unit
Envision
Unit
Envision
Unit
Heater/
Rejector
Vertical - Closed Loop/Ground Source