RE: Winterizing Your Air Conditioning System

Dear Website Customer: The weather in North Texas always seems to be a surprise this time of year. It can be in the 80’s one day and below freezing the next. Needless to say, this is very detrimental to our health, and the health of our often neglected heating and cooling equipment. Here are some common sense items of interest that we sometimes forget this time of year.

I. Water Cooled / Heated Systems

1. Water freezes at 32 degrees - This has a special relevance to any heating or cooling system that uses water to circulate comfort to a building. If your system is a hot water heating system, a chilled water cooling system, or you have a cooling tower for heat rejection in your cooling system, special care must be taken when the temperature drops and freezing can occur. If you have a cooling system where freezing water can occur, the best course of action is to completely drain and winterize the system. This must be done thoroughly and completely. Any water that is allowed to stay in an exposed pipe or component of the system can freeze and cause severe damage.

2. If the system cooling is required year round, then it is not possible to drain the system water. Very special care must be taken to provide heat tracing and component heaters to any area that can freeze. These heaters and related controls must be checked carefully to insure that they are available when required, and off when they are not required.

3. Heating systems and boilers with exposed piping must be treated with the same care as year round cooling systems to avoid damage. Glycol or anti-freeze can be added to water systems in extreme cases, but always results in a loss of system efficiency.

II. Air Cooled Systems

Air cooled systems do not require near the care that water related systems do. The main thing to do is to verify that the compressor sump heater is in good working condition. This will prevent many compressor related problems that occur as a result of refrigerant saturating the compressor oil. In other words, if this heater is not working well, compressor damage can occur.

III. Heat Pump Systems

Heat pump systems require a special degree of attention be paid to the control systems and refrigerant charge. These units have somewhat complex control systems to enable the unit to work properly in cold weather. They must automatically defrost frozen coils, switch on back up electric strip heaters, and cycle for comfort. Additionally, the refrigerant charge must be properly balanced to work in the heating mode. All things considered, these units require a greater degree of maintenance than the average unit.

The long and short of it all is simple: a little thought and planned maintenance goes a long way toward insuring your winter comfort--and minimizing problems when the air conditioning is needed again. If you have any questions, please call me or Josh Kahn at 631-1010. We’d like to hear from you.

Sincerely, KAHN MECHANICAL CONTRACTORS Ann R. Kahn

TACL A370C