A question i often got when working in an air conditioning store was “can i change my existing ducted evaporative system straight over to a ducted reverse cycle Melbourne Air Conditioning Installation?”. The simple answer is no. Below are the reasons as to why you cannot simply change the air conditioning systems over.
Reverse cycle air conditioning grilles (or outlets) are positioned near windows and away from doors. This allows the air to condition the heat/cold that comes in directly through the windows. The airflow for a reverse cycle system should also take the longest route back to the return air grille. If an air conditioning outlet was located next to a door, the air would simply be sucked underneath the door towards the return air grille and the room would have hot spots near the window.
Evaporative air conditioning grilles however are located by the doorways. The evaporative unit’s airflow should take the longest path through a room and out the window. If they were located right next to a window, the air would simply flow out the window and hot spots would be caused near the doorways and in the far side of rooms.
Because of this it is not advised to place reverse cycle grilles in a same spot where a ducted evaporative grille was previously placed. Although it can be done it will severely lessen the effectiveness of the system. The best option is to start fresh and put the new reverse cycle grilles in the correct desired location. However, this would mean you would need to patch and paint the holes in the ceiling left by the removal of the old evaporative grilles and this can be a costly job.
Another option would be to add extra grilles as needed. You can consider leaving grilles near the doorways from the evaporative system and add extra grilles by the windows if needed.
Another common question people ask is if they can use the same ducting that was in the roof from their old evaporative unit for their new reverse cycle system. Once again unfortunately the answer is no.
The ducting used for evaporative air conditioning units is far larger than that needed for reverse cycle Brisbane ducted air conditioning. Evaporative units use ducting around the 16-20 inch mark. This large size duct is used by evaporative air conditioners as the air is extremely fast blowing and it aims to draw in air to the amount of 40 times the cubic area of your house per hour. Reverse cycle ducting is mostly only around the 12 inch mark in diameter. This is because reverse cycle air conditioning is far slower moving.
Evaporative air conditioning ducting is also usually only slightly if at all insulated. Reverse cycle ducting should always be insulated by a minimum of 2 inches to preserve the cooling/heating.
So if you want to swap your existing evaporative air conditioning system over to a new reverse cycle ducted system, you are best to start from scratch. Be sure to get quotes for the cost to patch and paint the ceiling before starting any work. And if people tell you they can simply swap a system over using the existing duct and outlets, ask lots of questions and be wary as they may not be around to help you once you have paid good money and your system is not working effectively.
In some cases using the existing grilles can be an option, but it would make the system less effective.