LG Air Con FM25AH Outdoor Unit in defrost Mode

Outside temp this morning in Leeds, UK was -2C @ 0800am, so the heat pump/air con was working hard to heat the inside of the house. These units are effective down to -15C, however efficiency starts to decrease the colder it gets. However the unit burns about 2kw of electricity when running at full whack but outputs 7kw of heat. About 350% more efficient. Compare this to a 2kw electric heater that burns 2kw and outputs 2kw of heat this is only 100% efficient!

This video taken just as the unit went into defrost mode, notice the steam evaporating off the coil. The coil was thick with ice on the outside of it before entering defrost.

Once the unit has defrosted the fan kicks back in and what looks to be loads of smoke billowing out the front is in actual fact steam from all the ice that has now melted.

Any questions please ask.

Category:

Science & Technology

Tags:

• Air
• Con
• Defrost
• Mode
• LG
• Conditioning
• Cold
• Ice

[AXNPictures]

For how long does the a/c run before entering in defrost mode ? And how cold should be outside to make it start auto defrost ?

[richardc1983]

@AXNPictures Depends on how long unit has been operating, the outside air temperature, heating demand (how hard the compressor has been working) etc etc. SO hard to say. On a day below 0C and high heating demand inside could be once an hour, on a day of say 5C it could be once every 4 hours but no visible frost on the unit just an oil return process.

[Jakeequa]

@fedders4 It is just the model of the outdoor unit. I like white better.

[KadirTurcia]

LG's new system outdoor units feature a white fan. fan and compressor needs produces inverter systems and internal, external environment, the transfer rate according to the settings. Class A energy efficient air conditioning and outer environment according to 40% -15 up to have a performance in heating

[garryt]

hvguy,

Richard is absolutely correct. These can be anything up to 535% efficient depending on conditions. Do some research before posting - try googling it!!

[richardc1983]

@hvguy The outside air, although very cold, bears energy. In the case of air to water pump, i.e. water are heated using the outside air, the pump uses this energy to heat the water cycling in the pipes. The energy is renewable but electricity is used to “pump” it inside the house. The energy invested in the pumping can be considered as a commission, the electricity is used to utilize the energy in the air for actual heating.

[richardc1983]

@hvguy AS someone has just posted above:

@hvguy:

You are absolutely wrong. It is a heat pump, so called because it is moving heat from one place to another, not burning energy to produce heat. The high efficiency is because you are taking heat from a "free source" - i.e. outside and moving it inside.

You are totally wrong and need to do your investigations... Google it!

[andywsm]

@hvguy

You are absolutely wrong. It is a heat pump, so called because it is moving heat from one place to another, not burning energy to produce heat. The high efficiency is because you are taking heat from a "free source" - i.e. outside air and moving it inside.

[andywsm]

@hvguy:

You are absolutely wrong. It is a heat pump, so called because it is moving heat from one place to another, not burning energy to produce heat. The high efficiency is because you are taking heat from a "free source" - i.e. outside and moving it inside.

[hvguy]

@Swipe650 but to move that refrigerant it uses power.. and moving heat is measured in BTU's.... so your basically creating energy...

how about this: what would be the efficiency of a gravity fed siphon system.. 1/4 hose, 5 gallons, 3 ft off the ground with a 3ft hose...