User Guide

7
Design Guide - HZH/HZV Series
vFlow
®
Internal Variable Water Flow
Industry-rst, Built-in vFlow
®
provide an ultra-high-
efcient, variable speed, internal water ow system. It
saves installers time and labor by avoiding installing bulky
external pumps, valves, or ow regulators. Multi-unit
installations are also much simpler with vFlow
®
systems, as
the units automatically adjust water ow across the system.
vFlow
®
is enabled by iGate
®
, which facilitates intelligent
communication between the thermostat, DXM2 control,
sensors and internal water pump/valve to make true
variable water ow a reality.
vFlow
®
is available in four variations:
1. Low System Pressure Drop Modulating Valve – High CV
motorized valve for central pumping.
2. High System Pressure Drop Modulating Valve – Motorized
valve for higher pressure water system such as water well
pumps.
3. Standard Head Variable Pump – multi unit/central pumping.
4. High Head Variable Pump – multi/individual unit pumping.
vFlow
®
delivers three main benets:
1. Easier and quicker unit installation as the ow control is
built in to the unit.
2. Superior reliability by varying the water ow to deliver
more stable operation.
3. Higher cost savings by varying the ow (and pump watt
consumption) to match the unit’s mode of operation.
Internal components
HZ units can be installed more easily and compactly than
its predecessors because water-ow components are
internal to the unit. It also saves installing contractors labor
and time by eliminating the need for an external ow
regulator or a bulky external pumping module.
Variable ow
vFlow
®
technology enables variable water ow through
the unit, with the DXM2 control adjusting the pump speed
to maintain an installer-set loop delta T. By controlling
the water ow, the system is able to operate at its optimal
capacity and efciency. vFlow
®
provides a lower ow rate
for part load where units typically operate 80% of the time
and a higher, more normal ow rate for full load operation.
Energy Savings with water circulation control
Units with vFlow
®
deliver higher operating cost savings
by varying the water ow to match the unit’s operation
(ex: lower water ow when unit is in part load operation).
Lowering the ow results in lower energy consumption by
the water pump (=higher cost savings) in vFlow
®
units.
In applications using vFlow
®
with internal variable-speed
vFlow
®
Internal Variable Water Flow Control
Variable speed pump or motorized modulating
valve delivers variable water-ow, controlled
by DXM2 control, based on loop water ∆T.
(ECM) pump, the ECM pump uses fewer watts than a
xed speed (PSC) pump, even at full load (see chart).
The ECM pump excels in energy savings in part load,
saving 70-80% watts compared to xed speed pumps.
The ECM pump can operate with independent ow
rates for heating and cooling, further saving more
energy.
In applications using vFlow
®
with modulating valve,
when the motorized modulating valve slows down the
water ow during part load operation, the external
pump consumes fewer watts, thus saving more energy.