| Counterflo
INDIRECT-FIRED INDUSTRIAL HEATERS The
Counterflo System of Heating
The Counterflo Space Heating System
The Counterflo system, by generating heat in a
self-contained floor mounted unit within the conditioned space, minimizes the problem of
air stratification. The coolest room air from the floor level is drawn into the base of
the heater. The heated air is discharged horizontally through optional high velocity
nozzles at a point just above the working level. The removal of colder floor air allows
the stratified warmer ceiling air to drop back into the working area, where it is further
dissipated by the action of the high velocity discharge air stream.
The recirculation of heated air within the working area,
and the virtual elimination of stratification combine to reduce the cost of heating while
providing more uniform room temperature.
Among additional advantages of the Counterflo system are
lower installation cost, with savings in ductwork and a reduction of the number of units
required, and lower maintenance cost due to increased equipment accessibility.
Complete Design Flexibility
Application
Counterflo indirect-fired heaters are well suited for a
variety of uses. The standard unit includes those components and controls needed for SPACE
HEATING and is shipped with an unmounted room or space thermostat. For HEATING AND
VENTILATING applications, small modifications are required along with the substitution of
a full modulation burner. For along with the substitution of a full modulation burner. For
MAKE-UP AIR applications, stainless steel tubes and headers are strongly recommended, in
addition to a full modulation burner. Special high temperature units are offered for
PROCESS applications. In some cases, these units can be designed to handle inlet air
temperatures as high as 400 degrees F.
Choice of Burner
Floor Mounted Upright CF-250
Counterflo Heater
Natural of propane has, oil and combination gas/oil burners
are offered in On-Off, Hi-Lo-Off and Full Modulation service. Full Modulation,
depending on model size and fuel used, is available with turndown ratios as high as 8:1.
Burner control sequences:
On-Off- provides full rate firing as controlled by an
on-off space thermostat.
Hi-Lo-Off- provides low fire (50% of input) or high fire
(full-input) as controlled by a two stage space thermostat.
Full Modulation- 2:1 turndown ratio provides a minimum fire
rate 50% of input, and 8:1 a 12 1/2 % minimum fire rate with infinite firing rate between
low fire and full input. The firing rate is controlled by a modulating space thermostat
while the burner circuit is controlled by an on-off thermostat.
Equipment Location
The many building types, configurations and different
heating applications present an endless variety of problems for the heating engineer. An
acceptable equipment location is normally a major consideration.
The Counterflo indirect-fired heater is available in a wide
range of sizes and models. If the recommended floor mounted upright system is not
practical, the equipment may be suspended horizontally from above, or even wall mounted in
an inverted position. Weatherproof outdoor Counterflo models can be selected
in those applications where indoor space is not available. |
