IBC Sl Series Installation & Operating Manual page 47

Flow rate (gpm)
Head @ flow (ft wc)
Table 8 SL 30-199 G3 Boiler Head Loss
Ensure that the pump is rated for the design circulating water temperatures; some pumps have a
minimum water temperature rating above the low temperature potential of the boiler. Following
installation, confirm the actual performance by measuring Δ°T (under high and low flow conditions)
after establishing the correct firing rate.
To use legacy heat, we recommend water flow after burner shutdown. There can be significant build-
up of energy due to the volume of heated water in the system. Default load settings will run the
boiler's primary pump for up to 15 minutes (900 seconds) after burner shutdown. Secondary pumps
can be set to run up to 5 minutes after burner shutdown (for the last calling load). As shipped, the
default settings will run the boiler pump for 5 minutes to place the legacy heat where it is useful.
To allow pump purge after burner shut-down, the primary pump must be under the control of the
boiler.
To simplify the control application, promote good loads and flow management, installers must
conform to the piping design configurations provided.
Propylene glycol usage
Warning
Do not use automotive-type ethylene or other types of automotive glycol antifreeze, or
undiluted antifreeze of any kind. This may result in severe boiler damage. Installers must
ensure that glycol solutions are formulated to inhibit corrosion in hydronic heating
systems of mixed materials. Improper mixtures and chemical additives may cause
damage to ferrous and non-ferrous components as well as non-metallic, wetted
components, normally found in hydronic systems. Ethylene glycol is toxic, and may be
prohibited for use by codes applicable to your installation location. For environmental and
toxicity reasons, IBC recommends only using non-toxic propylene glycol.
Propylene glycol solution is commonly used in a closed loop where freeze protection is required. Its
density is lower than that of water, resulting in lower thermal performance at a given flow and
pressure. Generally, a 50%:50% solution of propylene glycol and water requires an increased
system circulation rate (gpm up 10%), and system head (up 20%) to provide performance equivalent
to straight water.
Boiler Head Loss - SL 30-199 G3
6 10
2.0 3.5
43
3.11 Water Piping
15 20 22
5.5 8.0 13.0