Pioneer PHR100-55, Instruction Manual, Page: 22 / 65

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Anti-freeze solutions expand more than water. For example: A 50% by volume glycol solution expands
4.8% in volume during a temperature increase from 32
o
F to 180
o
F, while water expands 3% over the
same temperature rise. Allowances must be made for expansion in system design.
A 30% mixture of glycol results in a BTU output loss of 15% with a 5% increase in head against the
system circulator.
A 50% glycol mixture results in a BTU output loss of 30% with a 50% increase in head against the system
circulator.
It is highly recommended that you carefully follow glycol manufacturer recommended concentrations,
expansion requirements, and maintenance recommendations (pH additive break down, inhibitor
reduction, etc.) You must carefully figure the additional friction loss in the system as well as the reduction
in heat transfer coefficients.
I. ZONING WITH ZONE VALVES
1. Connect heater to system as shown in the Piping Details diagrams. Properly size circulators for friction
loss of zone valves and piping for proper operation.
2. Connect DHW (domestic hot water) piping to indirect storage water heater as shown.
J. ZONING WITH CIRCULATORS
1. Connect heater to system as shown in the Piping Details diagrams. Properly size each zone circulator
for friction loss of each zone for proper operation.
2. Install a separate circulator for each zone.
3. Connect DHW piping to indirect storage water heater as shown.
K. MULTIPLE HEATERS
1. All piping shown is reverse return to assure balanced flow through the connected heaters.
2. Connect DHW piping to indirect storage water heater as shown.