Airtech Pty Ltd
attn. Barry Machin
971 South Road
Melrose Park SA 5039

1 December 1998

Dear Barry,

As discussed on the phone yesterday, I'm attaching a plan of the new part of the house with sufficient of the old plan to enable you to relate its position. We plan to use the existing unit for cooling only in the extension. We appreciate that there may be a problem cooling the entire house with the current unit, but on the other hand we note that at no time in the last summer did the temperature in the house exceed 27° without air conditioning. The biggest problem I see will be keeping the back part of the extension cool without more sophisticated control methods. In this connection, I would ask you to ensure that the dampers are capable of frequent opening and closing while the unit is operating. .P In addition, I remind you of the following still unresolved problems:

• The existing ductwork appears to be incorrectly laid. The two bedrooms at the extreme bottom left of the current plan are connected by a single relatively long and thin duct, whereas the study is connected by a shorter and wider one. Similar considerations apply for the laundry, which appears to have too short and wide a duct. This would completely explain the problems we have with the study and laundry being too warm.
• The thermostat is not operating correctly. Although it was adjusted last winter, the cut-in and cut-out temperatures appear to have diverged and are now about 3.2° apart.
• In addition, when cooling, the unit does not stop cooling when it reaches the target temperature. Recently, when the outside temperature was about 32° and the inside temperature was about 24°, I turned the unit on to cool to 22°. After it reached 20.5°, I changed the required temperature to 29°, but it continued cooling.
• The cover of the thermostat does not close. This appears to be due to faulty construction: we can't see any damage done to it, and it barely shut from the beginning.
• We still do not have a satisfactory resolution to the icing problem. As I explained, I believe that a lot of the problem is due to the way the external unit was mounted: it was pointing into the weather (West), and the winds can be very high in this area. I believe that the last case of icing was caused by a combination of wind, which reduced the effectiveness of the fans, and rain which landed directly on the cooler, thus causing the icing.

  As you can see from the plan, we will be building an open carport over the area where the external unit is located. I believe that this will solve the problem, but we will not know this until next winter. If you are agreed, we can postpone this point until the winter, under the understanding that if there still is icing next winter, you will address the issue. Please confirm that you agree to this approach.

Sincerely,

Greg Lehey