E. SYSTEM DISTRIBUTION CONNECTION AND SCHEMATICS Refer to the drawings on the next few pages for general schematics associated with a GARN® WHS unit heating a single building containing either a single zone system or a multiple zone system. The following drawings are schematics; as such it is neither detailed nor sufficiently complete for construction. Therefore, a comprehensive design must be completed by either an Engineer or Mechanical contractor who is knowledgeable about GARN® zero pressure heating equipment and the particular site conditions for which the schematic is proposed. This schematic is NOT a document of sufficient detail to yield a functioning heating system.
ZERO PRESSURE, FIXED TEMP - PRIMARY ONLY PUMPING:
A zero pressure, fixed temp system delivers a fixed water supply temperature to a non-pressurized hydronic heating system. Such a system is “ zero-pressure ” because the heating system is in direct contact with the atmosphere at the GARN unit. As the system heats up, the expansion of the water is reflected in the level of the GARN unit.
Advantages
Disadvantages
Simple.
Cannot connect to a pressurized system. If pumping to a level higher than the level of the GARN unit, the system will drain back to the GARN which could prevent many pipes from remaining “ wetted ” .
No expansion tank required.
Constant speed or variable speed pump can be used.
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Hydronic System Design Manual ©DECTRA CORPORATION - March 2013
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