Refrigerative Air-conditioning

I am interested in purchasing your SureCool Air Conditioning Sizing software but am not sure which version is appropriate for my situation. I have already had some quotes for an appropriate unit and am confused by the range of sizes offered - from 2.5 HP to 4.00 HP. I trust your software may be able to help clarify the correct sizing but am not sure if my situation is appropriate for the Room SureCool or whether I may be in Office SureCool territory.

The planned Air Conditioner is for domestic use, however the area to be cooled (and heated) perhaps may not fit the normal definition of a “room”. The area is a large open space consisting of a lounge room, dining room, kitchen and family room - about 70 square metres with the rooms forming a “U” shape. The only viable position for the intended split, wall hung unit would be at the leg of the “U” directing air across the base of the “U”.  (N.B due to house construction, a ducted unit is nor suitable)

The ‘Room SureCool’ will suit your needs. (Office SureCool allows extra for the greater internal heat load in offices due to the number of computers, fax machines, different numbers of people etc.) You will need to split the U shaped room into two sections and add the results, however this is fairly easy. The situation where you have such a range of offerings is certainly the situation for which I designed the calculator.
When comparing units, make a point of comparing the cooling (or heating) kW not horsepower as some manufacturers have been getting very optimistic in their hp claims.

When Selecting equipment based on the Kw required from results, with Inverters do you select on the nominal or peak or somewhere in between?

I myself select on the nominal, because I have heard of them overloading if selected on the peak, however it may be that a value in between works, but I have not tested this theory.

By selecting oil the nominal you ensure it has enough capacity to give a quicker initial cool down.

Does your ducted system software not only calculate how much heat energy KW required but does it also include information on the air flows required per rooms or spaces to be ducted?

No, I have tried to keep the software as simple as possible for ease of use.

Hello Clive, interested in your programs but just a few questions first, I am sending this e-mail from New Zealand (Wellington).
Obviously its a lot colder here than South Australia. Do the calculators have all the relavant factors for our colder conditions and greater heat losses?

Yes, the program has 4 separate zones covering New Zealand.

I bought an Air Conditioner recently. The circuit breaker after a short time trips and shuts off the air conditioner. It works longer on the older wiring in the house and the
newer addition section it trips faster. was there a problem with the air conditioner last year and what should I do?

I suspect that the air conditioner is drawing more current than your wiring can handle.
Check the manufacturers recommended circuit breaker size, as the manufacturer probably requires the circuit breaker to be rated much higher than the rated current of the air conditioner.

My window unit (RAC) blows cold air, but the fan won’t start unless I push it. Once it is going it runs well until I shut it off, then on restart the problem starts over.

You may be experiencing low voltage problems. Is the wiring to the house adequate?
There may be a buildup of dust on the fan. Try cleaning the fan blades (make sure the air conditioner is disconnected).
If the motor is old, the bearings may have become tight. This probably means a new fan motor.

I am assuming the symptom is that the circuit breaker is tripping out. If the air conditioner is tripping out on high head pressure, different causes apply see troubleshooting in the main wibsite.
If it is a new air conditioner, the most likely situation is that the wrong size or type of circuit breaker was used.
If it is a conventional air conditioner the current when the compressor starts is much higher than the running curent. If it is an inverter air conditioner, the maximum current can be around 50% more than the rated current.
It may simply be the system design (particularly a high outside air or other unusual system)which allows for a very high current without tripping the other safeties.
The other possibility is a fault. In general it is going to take a refrigeration mechanic to actually identify the problem.