Table of Contents
Advertisement
Water-to-Water System Design Guide
Part II: Load Side Design / System Design & Selection
System Descriptions
Figure 2-4: Component Legend for Drawings 2-1 to
2-9
3-Way Valve - Manually Operated
3-Way Valve - Motorized
M
Mixing Valve
T
Ball Valve
Gate Valve
Pressure Reducing Valve
Drawing 2-1: 50YEW Typical Load Piping -
Indirect Water Heater / No Cooling or Separate
Cooling System
If heat exchanger
of indirect water
heater does not
have enough
mass, see
drawing 2-9
To/From
Radiant Floor,
Radiator,
Baseboard,
or Fan Coil
Heating System
12
Component Legend
Pressure Relief ("Pop-Off") Valve
Check Valve
Union
Pressure/Temperature (P/T) Port
Circulator Pump
Heat Exchanger
P.R.V.
H
C
Indirect
Water Heater
Thermistor
Note 2
H
C
Heating
Buffer Tank
Note 3
Thermistor
Note 2
Bryant: Whatever It Takes.
Drawing 2-1 – 50YEW Typical Load Piping Indirect Water Heater
/ No Cooling or Separate Cooling System: System #1 uses one
or more water-to-water units and a buffer tank for each unit.
Drawing 2-1 shows a typical piping arrangement for this system.
A thermistor mounted in an immersion well senses buffer tank
temperature, which allows the internal controls (50YEW units
only) to engage the water-to-water unit compressor, load pump
and source pump(s) when the tank temperature drops below
the set point, typically 120°F [49°C] or less. The radiant fl oor (or
baseboard, radiator, fan coil, etc.) system therefore is completely
isolated from the water-to-water unit. The controls for the
hydronic distribution system energize pumps and/or zone valves to
allow heated water in the buffer tank to fl ow through the heating
distribution system. Potable water is heated via an indirect water
heater, so that heating system water and potable water do not mix.
The 50YEW unit has an internal motorized valve, which allows
the load pump to send heated water to the buffer tank or the
indirect water heater. A thermistor mounted in an immersion well
senses DHW tank temperature, which allows the internal controls
(50YEW units only) to engage the water-to-water unit compressor,
load pump and source pump(s) when the DHW tank temperature
drops below the set point, typically 130°F [54°C]. If desired,
cooling is accomplished with a separate system.
Air Vent
Note 1
Exp
Tank
IN
IN
OUT
OUT
OUT
HTG
DHW
HTG
DHW
M
50YEW
Unit
Load HX
Source HX
(brz plt)
(coaxial)
See drawings in section 3 for Source connections
IN
NOTES:
1. Place air vent at the highest point in the system. If
internal expansion tanks are installed, only an air
vent is required.
2. Thermistors should be installed in an immersion well.
Locate thermistor in the bottom half of the tank.
3. If electric water heat is used instead of buffer tank, see
drawing 2-7.
4. P/T (pressure/temperature) ports are internal for
50YEW units on load and source connections.
5. Other components (additional ball valves, unions, etc.)
may be required for ease of service. This drawing
shows only minimum requirements. Your specific
installation will dictate final component selections.
6. Buffer tank must be approved as a heating vessel.
7. Local code supercedes any piping arrangements or
components shown on this drawing.
03Oct07
Advertisement
Table of Contents
