More Air Conditioning

I recently had an extra room added to my house. When it came time to arrange for air conditioning to be installed, it turned out that there was a huge amount of choice on the market now. To ensure we bought the best unit we could I decided to use previous experience and some research to pick one myself.

What Brand

The short answer. Daikin. This was determined on many factors. Firstly our house was originally air conditioned by a 25 year old Daikin. It reliably heated and cooled the room for those 25 years regardless of the outside temperatures. The only reason this unit was replaced was that it’s appearance was no longer suitable for the room as it did really look 25 years old.

Secondly the replacement for this unit was also a Daikin. This unit was a multi-split meaning that two indoor air handlers could be supplied by the one outdoor unit. A 6KW air handler was placed in the kitchen/dining area (where the old Daikin was) and a 7.1KW air handler was placed in the computer/entertainment room. These were both connected to the same 12KW outdoor unit. These two units have performed just as well as the old unit. This unit is also incredibly efficient as it uses a maximum of 2190 watts of electricity to produce the 12KW of heating and cooling power.

Furthermore Daikin, at the time, were the only air conditioning manufacturers producing units with the new R-32 refrigerant (the substance which transports heat in/out of the room). R-32, or Difluoromethane as it is chemically known, is essentially methane except two of the four hydrogen atoms have been replaced with fluorine atoms. This new refrigerant has no ozone depletion factor as well as a higher efficiency. These positive features will lead R32 to become the dominate refrigerant in most domestic and light commercial air conditioning applications. Due to the efficiency of this refrigerant and the system as a whole, it is able to provide 3500 watts of cooling (or heating) for only 860 watts of electrical power consumption.

Due to the success of the existing units and the new R-32 refrigerant, I decided that we should install a Daikin in the new room.

What Size

Ultimately the decision for the sizing of the unit would be left up to the installers. However I could make a rough estimate on the size that would be needed.

Note: In Australia the heating and cooling ability of air conditioners is measured in kilowatts (KW). Kilo essentially means that the 1000’s of watts so 3.5KW would be 3500 watts of cooling or heating power.

From past experience I knew that it would have to be larger then 2.5KW as a similar sized room had a 2.5KW Air conditioner which is only just capable of cooling the room on the hottest days. This other  room also does not have the extreme heat loading experienced by the new room, due to the afternoon sun. After consulting the Daikin catalogue the sizing of the units went 2.5KW, 3.5KW, 4.6KW. Knowing that 2.5KW would be too small and that 4.6KW would probably be too powerful I estimated that the size of the unit would be 3.5KW.

After consulting with the installer it was determined that the size of the unit would indeed be 3.5KW. The indoor unit would be a FTXM35PVM and the outdoor unit would be  a RXM35PVM.

Installation

The company doing the installation would be Arctic Air Conditioning.  Luckily they could arrange installation a day after the quote was issued. When it came to the day of installation they were more than happy to let me watch the entire installation from start to finish due to my interest in air conditioning.

The plan was to mount the indoor unit in the middle of the right hand wall, run the refrigerant pipes through the wall and down to underneath the deck where the outdoor unit would be placed.

This is the wall that the air conditioner will be installed on.
This is the wall that the air conditioner will be installed on.
The outdoor unit would be installed underneath the deck here.
The outdoor unit would be installed underneath the deck here.

The total installation went as follows:

  1. Unpacked the indoor and outdoor unit from their boxes
  2. Attached the indoor unit mounting plate to the wall.
  3. Drilled a hole with about a 50mm radius through the wall to pass the refrigerant lines through.
  4. Passed a power and data cable through the hole from the outside (the would eventually be connected to the outdoor unit.)
  5. Attached the indoor unit to the mounting plate and passed the refrigerant lines through the hole.
  6. Attached the pipe cover to the outside wall (all of the pipes and cables would run through this to protect them from the weather and make the installation more visually pleasing.
  7. Created a flared joint between the indoor unit pipes and the length of copper piping that would connect to the outdoor unit.
  8. Placed the outdoor unit on a pre cast cement block and pushed it under the deck.
  9. Installed a power point for the outdoor unit to plug into (more on this further down page)
  10. Created another flare joint to connect the pipes to the outdoor unit.
  11. Connected a vacuum pump to the system to remove all the air out of the pipes and the indoor unit’s coil. (There must be no air in the system, only refrigerant.)
  12. Opened the values on the outdoor unit to allow the refrigerant to circulate around the system. (These systems come pre charged with refrigerant, which is stored in the outdoor unit. When the values are opened it then fills the entire system.)
  13. Performed a test run.
This is the back of the indoor unit before it was installed.
This is the back of the indoor unit before it was installed.
This silver part was the mounting plate for the indoor unit.
This silver part was the mounting plate for the indoor unit.
This is the indoor unit fully installed.
This is the indoor unit fully installed.

 

The pipe cover running down the wall
The pipe cover running down the wall
A side view of the outdoor unit, under the deck
A side view of the outdoor unit, under the deck
The front view of the outdoor unit.
The front view of the outdoor unit.

Interesting Points

The Outdoor Powerpoint

When electricity was run to this room it was run as a shared circuit. Essentially this meant that the power points and the lights were all on the one circuit and connected to one circuit breaker in the fuse box. However here in Australia air conditioners must be connected to their own circuit breaker so that they can easily be isolated if they require maintenance.

The solution for this was to install an outdoor power point and plug the air conditioner in. This would allow it to be connected to the shared circuit yet still allow it to be legally isolated. As the air conditioner only uses 860 watts of electrical energy at full capacity, a standard power point could be used.

Video Of Air Conditioner Running