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.