28
HYDRONIC INSTALLATIONS
NOTE: It is recommended that the circulation
pump in all hydronic systems be located in the
hot supply line, not in the return line (see Fig. 36
and 37).
Evaluate the existing hot water heating system before
starting the installation. If the existing hot water heating
system has been unable to maintain the temperatures
in the home at any time during cold weather before
installing the outdoor furnace, then the hot water heating
system is not adequate. More baseboard or other type of
heat exchanger must be added.
If a water-to-water heat exchanger is to be used with
an existing heating system, the existing heating system
must be able to adequately heat the building with a
water temperature of approximately 165°F (74˚C).
Some existing finned tube baseboard hot water heating
systems are designed to operate with water temperatures
up to 220°F (104˚C) or higher.
If the existing heating system is marginal or designed to
operate with water temperatures above 165°F (74˚C),
there are alternative installation procedures that will
make the existing system work very well with the
outdoor furnace. These include:
1. Add more finned tube water baseboard heaters or
panel radiators.
2. A water-to-air heat exchanger with a thermostatic-
ally controlled fan can be installed in the lower part
of the building being heated (Fig. 36). This can
increase the amount of heat added to the building,
helping to maintain a constant temperature. This
heat exchanger can be added in the return line of the
system after the water-to-water heat exchanger.
3. An additional radiant heating circuit can be added to
heat areas that require additional heat.
H
C
M
R
Existing
Water
Heater
Existing
Boiler
Hot Supply from Pump
on Outdoor Furnace
Return to Outdoor Furnace
Optional Thermostatic Valve
Water-to-water
Heat Exchanger
Circulating
Pump
Supply
Return
This valve should be closed
if the outdoor furnace is not
being operated in the summer.
This pipe must not exceed a
height of 4 inches (10 cm)
above top of water heater.
Flow check or zone
valve here will prevent
thermal circulation and
overheating of
building. It is recom-
mended that the
circulation pump in all
hydronic systems be
located in the hot
supply line, not the
return line.
NOTE
Installer must comply with
all applicable codes and
regulations.
NOTE
Outdoor furnace water temp
setpoint should be set at
185˚F (85˚C) minimum.
NOTE
A pump must be installed in the hot
supply line between the outdoor furnace
and thermostatic valve.
Water-to-Water Shell & Tube Exchanger with Existing Boiler
Optional Water-to-Air Heat Exchanger
Water-to-Water
Heat Exchanger
For illustration purposes only,
water heater styles may vary.
Fig. 36
Section 6 - System Installation
