IBC VFC 15-150 Manual

2-11
BOILER SYSTEMS AND OPERATION
VFC 15-150 - VFC 45-225 MODULATING GAS BOILERS
5. Eachoftheboiler’s3Loadpositionscanbeconguredforanytypeof
heating. VFC boilers are factory shipped with default settings as follows:
Load 1 set as Space Heating or Reset Heating, with High Mass Radiant
Floor set as the terminal type; Load 2 as Set Point; and Load 3 as DHW. The
factory defaults can be changed using the Dene Load 1-2-3 lines to reverse
the order, turn off a Load or do whatever the installer desires.
6. Once the appropriate Loads are set, use the left-hand key to move back to the
Setup Heating Loads screen, then move down to Congure Load 1 (and hit enter).
7. Thescreenwilldisplaytheinputeldsappropriatetothenatureoftheload
selected, e.g. Design Outdoor Temp. for a Space Heating (or Reset Heating)
load.Note:theseeldsarepre-loadedwithdefaultvaluesthataretobe
alteredtoreectthedesiredparameters.
8. For reset loads, the initial selection to be made addresses the “emitter” type
– choices include H(high) Mass Radiant, L(ow) Mass Radiant, Baseboard, Air
Handler etc. An appropriate reset curve is called up through this procedure.
Reset loads carry a default value for Design Outdoor Temp. of -10°F (-23°C).
Raise or lower this as appropriate – e.g. for Vancouver, use 19° to 25°F,
while for Edmonton -35°F would be appropriate. Note: - for some users, this
adjustment may seem counter-intuitive. Moving the setting toward a colder
design value will have the effect of reducing the boiler’s target temperature
for any given weather, because a given current condition is relatively warmer
than the designated “coldest” day.
Moving down the screen, set the Design Supply Temperature – the targeted
temp.forcirculatingwateronthecoldestday.Foranin-slabradiantoor
thiswouldtypicallybe125°F(50°C).Fornnedtubebaseboardstypically
drivenat180°F,try160°Fmax.instead,topromotecombustionefciency.
For air handlers, try running 20°F lower than typically used. Of course, the
appropriate setting will depend on the characteristics of the emitter and the
building but in general the VFC modulating boiler’s large throttle turndown
will allow better average temp. control, permitting lower maximums.
9. For Reset Loads, move down the screen again to display more lines;
Use the Summer Shutdowneldtoenterathresholdtemperatureforthe
avoidance of heating during warmer times. This is typically set at 60° to 65°F
so as to eliminate excessive boiler cycling in marginal heating conditions.
Use the Minimum Temp.eldtooptimizeboilerruntimesonlowmassloads.
Finned tube baseboards sink very little heat when operated below 100°F;
application of a “full reset curve” (e.g. 160°F right down to a 70°F room
target) would cause boiler cycling in light-to-moderate heating conditions.
Set baseboard minimums at 100-120°F and aim for 4 or less cycles/hr. A
minimum setting can also be used to enhance home comfort with single or
excessive speed air handlers to avoid the cool blast effect. Set the lowest
possiblelevelforcombustionefciency.IBC’shighefciencyfullymodulating
air handlers (AH60 or CAF60) can use a minimum as low as 100°F to
achieveupto95%efciencywhencombinedwiththeVFCmodulating
boiler’s wide throttle turndown.

IBC VFC 15-150 Specifications

General

Brand	IBC
Model	VFC 15-150
Category	Boiler
Language	English