Function Overview; Intended Use And Functions; Efficiency Up To 98 - Slant/Fin VSL II User Instructions

3 - FUNCTION OVERVIEW

3.1 - Intended use
and functions
The boiler is designed to be used for
central heating systems for residential
and light commercial use. Any other
use is prohibited.
The boiler can be installed with a Direct
Vent system or with a one pipe vent
system using room air.
The boiler can be connected to an
indirect water heater for the production
of domestic hot water.
3.2 - Efficiency up to
98%
When the outdoor reset is activated (an
outdoor sensor is connected), the boiler
always work at the maximum efficiency.
It will automatically change the supply
temperature in relation with the outdoor
temperature (Outdoor reset).
The graph in Figure 4-2 shows an
example on how it can work.
This graph represents an installation
where the supply and return
temperatures are 139°F and 115°F
respectively , and the outside
temperature is 23°F. The outdoor
reset drives the boiler, to progressively
reduce the supply temperature and
thereby optimize the efficiency. It
changes from 87% when outside is
-10°F, to 94.8% when outside is 23°F
and up to 98% when the outside
temperature rises up to 67°F.
Figure 3-1 Outdoor reset control to optimize the efficiency
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