Balancing a Warm-Air Heating System

It is not always necessary to go to the expense of zoning to ensure that each room receives enough heat. Sometimes a heating system can be balanced by reducing the air delivery to rooms or sections of the structure that require less heat. This results in automatically diverting more air and heat to those areas that require it.

The procedure for balancing a warm-air heating system is as follows:

1. Pick a day for balancing the system when the outdoor dry — bulb temperature is 40°F or below.

2. Open the dampers in all warm-air outlets as widely as possible (Figure 6-9). The same holds true if the dampers are in the supply ducts (Figure 6-10).


Balancing a Warm-Air Heating System

Figure 6-9 Adjusting floor diffuser to full open position.

Balancing a Warm-Air Heating System

Figure 6-10 Adjusting supply dampers to full operating position.

3. Leave the thermostat at one setting for at least 3 hours, and make certain the furnace blower is running.

4. Check the temperatures in all rooms. This can be done with thermometers (if you are certain they register equally), or sim­ply by making your own judgment.

5. Leave the dampers in the coldest rooms wide open, and adjust the dampers in the warmer rooms to obtain the desired bal­ance. After each adjustment, allow the system to stabilize for at least 30 minutes before checking the temperature or mak­ing the next adjustment.

When balancing a heating system, do not expect immediate results. A little patience makes it well worth the effort.

Posted in Audel HVAC Fundamentals Volume 1 Heating Systems, Furnaces, and Boilers