System Design
For proper operation of the heating system, the boiler, the radiation system, and maximum
heat loss of the building must be considered. The boiler selected should provide between 110%
and 130% of the maximum design heat loss of the building. The radiation system should be
designed to properly dissipate the heating capacity of the boiler at the radiation system design
temperature.
The recommended cold fill pressure of the system is 12 psi; this pressure should leave at least 4
psi at the highest point in the heating system. Pressure will decrease at a rate of 0.433 psi per
foot above the fill point. An expansion tank must be included to allow for approximately 4%
expansion of the water in the entire heating system. As the water in the system is heated the
pressure will increase, but a properly sized expansion tank will prevent the pressure from
exceeding the recommended operating pressure.
The radiators or floor system should be designed with parallel loops. If too many radiators or
floor loops are connected in series, the accumulated heat loss may cause uneven heating. The
minimum recommended flow rate must be used, but higher flow rates may give more even
heating. If a number of parallel heating circuits are used, valves are usually required to balance
the flow in each circuit to provide uniform heating.
A zoned heating system is also possible with separate heating zones and individual
thermostats in each zone. Individual thermostats in each zone can control a zone valve, or a
circulation pump providing flow to that zone. End switches on the zone valves can be wired in
parallel to the thermostat connection of the boiler.
The entire heating system must comply with any local codes or regulations.
Installation
Location
(1) The site selected for installation of your boiler should leave at least 24” of clear space in
front of the unit. The sides and bottom require only enough room for plumbing and
electrical connections (see Fig. 2). The rear of the unit is considered a “Zero Clearance”
face (see Fig. 2). When mounting the boiler on the wall, ensure that the wall can
withstand the weight of the unit including water (approximately 60 lbs.). Mounting tabs
are provided on top for 3/8” bolts or screws, these are for wall mounting.
(2) The space selected should be well ventilated and kept normally below 77º F or 25ºC. It
must be clean, and dry. The boiler must not be subjected to water leakage, drips,
splashes, or spray. Flammable materials must not be used or stored anywhere near the
boiler.
(3) Though the unit is suitable for wall mount, only the rear face indicated as “Zero
Clearance” may be mounted against combustible surfaces.
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