FAQ : Air Conditioners

Before you buy


I live near the coast and am worried about the coil rusting?


Fujitsu have the coated outdoor unit coils with Blue-Fin treatment, which will minimise corrosion to the coil from rain and sea spray.
Please consult the technical literature that comes with the air conditioner to help you correctly maintain air conditioner.

What happens if the unit is too small for the room?

If a unit is too small for the room, the unit will be required to operate harder to achieve and maintain the desired temperature, which may cause extra wear and tear on its components and increase running costs.
Please use the economatch on this kiosk to help you choose the right air conditioner for you.

What happens if the unit is too large for the room?

If a unit is too big for the room, it will cause the unit to "short cycle", which means the output of the unit will ramp up and down too frequently. This can lead to fluctuations in the room temperature and excessive noise.
Please use the economatch on this kiosk to help you choose the right air conditioner for you.

Can I have a wired controller for my air conditioner instead of a wireless one?

Some Fujitsu models have different control options available, in some cases you may need to buy an optional part to allow this.
Please consult with your salesperson in order to find out the options that best suit your needs.

Should I get a single phase or three phase Air Conditioner?

You should always choose your Air Conditioner according to the requirements of your room rather than just the power supply available. 3 phase Air Conditioners require a 3 phase power supply and are generally used for areas requiring a higher heating/cooling capability.

Should I just replace the current machine with a new one of the same capacity or should I re-check the sizing?

It is always best to have an Air Conditioning specialist check your requirements as some of the factors may have changed over time. Some home appliances may require consideration and also any changes to floor plan or insulation should be considered.
Please use the economatch guide on this kiosk to help you choose the right air conditioner for you.

Why don't we talk in HP (Horse Power) anymore in Air Conditioning?

Horse power is a power rating for the compressor; this does not take into account the actual cooling and heating performance of the system. Kilowatts (kW) are a rating for the cooling/heating output of the entire Air Conditioner working together and not just the compressor.

What is VRF?

VRF is short for “Variable Refrigerant Flow”. It is a type of direct expansion (DX) multi-split system that incorporates a variable capacity compressor with a network of multiple indoor fan coil units. A VRF system increases efficiency by providing cooling or heating only to the individual zones where conditioning is required. Most VRF systems also employ a stand-alone controls and communications network.

How is a VRF system different from a conventional system?

A conventional system usually operates at a fixed speed. On days where the full capacity is not required, the system will turn off and on to maintain the space temperature. These systems will also have a single indoor unit connected to a network of ducts. A fan distributes air through the ducts and brings return air back to the central system. This is less efficient than a VRF system because it can only heat or cool the entire system; there can only be one set point. Also, the fan and duct losses of a conventional system can add an additional 30% to the total energy consumption.

What is a Heat Recovery or Simultaneous VRF system?

A heat recovery VRF system has the ability to cool one room (pull heat from one room) and distribute heat to another room. By doing this, the efficiency of the system is improved. While this is effective for some applications, there are also additional material and installation expenses associated with Heat Recovery. For many applications, the energy savings does not justify the additional installation costs. Instead, by using proper zoning and system design, a Heat Pump VRF system can be designed to provide comfort for all occupants.

How is IEER Calculated?

The IEER rating requires that the unit efficiency be determined at 100%, 75%, 50% and 25% load (net capacity). These efficiency values are then weighted based on real world conditions with each efficiency given a weighted value using the following equation:

IEER = (0.020 · EER@100%) + (0.617 · EER@75%) + (0.238 · EER@50%) + (0.125 · EER@25%)

Because if improved part-load performance of VRF systems, IEER values should always be better than full load value of the system.

How is it possible for a VRF system to produce better part-load efficiency?

When a VRF system is operating at part-load capacity, the heat transfer across the indoor and outdoor coil is significantly improved. For example, if a 20 ton VRF system were operating at 50%, it would be delivering the performance of a 10 ton system. However, this “10 Ton System” would have the coil surface area of a 20 ton system. This drastically improves the efficiency of this system

What is the Heating Seasonal Performance Factor (HSPF)?

HSPF is the total heating output of a heat pump, including supplementary electric heat, necessary to achieve building heating requirements during its normal annual usage period.
This is calculated by dividing heating by the total electric power consumed during the same period.

Does a VRF system require Traps and Sight Glasses?

Because of efficient oil management, a VRF system does not require any traps or sight glasses. Instead, most of the oil is collected in the oil separator, located immediately after the compressor. For the small amount of oil that makes its way into the system, a VRF system will go into “oil recovery” mode. During oil recovery, the compressor ramps up and pushes any lingering oil back to the accumulator where it can be returned to the compressor.

Can I deliver greater than 10 tons from a 10 ton system?

This is a common misconception. A VRF system often allows for a greater connected capacity than the condensing unit. This is beneficial for applications where there are multiple zones which have a large total capacity, but where every room will not call for heating/cooling at the same time. A VRF system can shift the load to the occupied rooms based on changes in demands. However, this system will never be able to provide more than the maximum total capacity of the outdoor unit.


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Function and Specification


How durable is the outdoor unit to sun/wind/rain?


Fujitsu's Outdoor Units are designed to live outside your home, as long as they have been installed and secured correctly these units can withstand day to day wind, rain and sun.

Is it possible to have less than 4 outlets for a cassette unit?

On certain models it is possible to only use three of the four air outlets. Please ask your installer for compatible models and information about any optional parts which may be required for this.

What are my options if I would like to feel Fujitsu Comfort in multiple rooms in my house?

There are a few options to condition multiple rooms in the same house. You could install separate split systems into each room that requires cooling or heating, you could look at an Inverter Multi system which requires only one outdoor to run up to 4 indoor units or you could consider installing a ducted system through your house. All of these options have benefits. Talk to your sales person to find out which air conditioner is best for you.

What happens if I only turn 1 head on when using an Inverter Multi System?

Inverter Multi systems are designed to operate with any combination of indoor units running. You can run just one indoor or a combination of indoors. This is what makes inverter multi systems a good efficient option for conditioning your home.

What is the defrost operation?

When outdoor temperature is very low with high humidity, frost may form on the outdoor unit during the heating operation, and it could reduce the operating performance of the product.
For frost protection, a microcomputer-controlled automatic defrost function is equipped in this air conditioner.

If frost forms, the air conditioner will temporarily stop, and defrost circuit will operate briefly (maximum of 15 minutes.)
OPERATION indicator on the indoor unit blinks during this operation.

If frost forms on the outdoor unit after the heating operation, the outdoor unit will stop automatically after it operates for a few minutes. Then the automatic defrosting operation starts.


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What maintenance is required from me for my new Air Conditioner?


At a minimum you need to clean and maintain the air filters for the indoor unit of your air conditioner as any build-up of dust or dirt will restrict airflow. Please ask your installer to give you a demonstration on how to take care of your air conditioner.

Does an Air Conditioner ever need re-gassing?

If an air conditioning is installed correctly then it should never need to be regassed. There is no such thing as stale gas or expired gas, the only reason for recharging will be if there is a leak in the system and this should be checked by a qualified Air Conditioning technician.


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How to use


Can I leave doors and windows open while operating the unit?


The best way to operate your air conditioner is to make sure all external doors and windows are closed. This ensures that the conditioned air stays inside the desired area to maintain the temperature in your room that suits you.


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What sorts of things aren’t covered under warranty?

What sorts of things are covered under warranty?


Please ask your purchase retailer or dealer.

Doesn't operate immediately

Indoor unit

If the unit is stopped and then immediately started again, the compressor will not operate for about 3 minutes, in order to prevent fuse blowouts.

Whenever power is interrupted, the protection circuit will prevent the unit from re-start for 3 minutes when power returns.

Noise is heard

Indoor unit

During operation and immediately after stopping the unit, the sound of water flowing in the air conditioner's piping may be heard. Also, noise may be particularly noticeable for about 2-3 minutes after starting operation (sound of coolant flowing).

During operation, a slight squeaking sound may be heard. This is the result of minute expansion and contraction of the front cover due to temperature changes.

During Heating operation, a sizzling sound may be heard occasionally. This sound is produced by the Automatic Defrosting operation.


Indoor unit

Some smells may be emitted from the indoor unit. This smell is the result of room smells (furniture, tobacco, etc.) which have been taken into the a/c.

Mist or steam are emitted

Indoor unit

During Cooling or Dry operation, a thin mist may be seen emitted from the indoor unit. This results from the sudden cooling of room air by the air emitted from the a/c, resulting in condensation and misting.

During Heating operation, the outdoor unit's fan may stop, and steam may be seen rising from the unit. This is due to Automatic Defrosting operation.

Airflow is weak or stops

Indoor unit

When Heating operation is started, fan speed is temporarily very low, to allow internal parts to warm up.

During Heating operation, if the room temperature rises above the thermostat setting, the outdoor unit will stop, and the indoor unit will operate at very low fan speed. If you wish to warm the room further, set the thermostat for a higher setting.

During Heating operation, the unit will temporarily stop operating (between 7 and 15 minutes) as the Automatic Defrosting mode operates. During Automatic Defrosting operation, the OPERATION indicator lamp will flash.

The fan may operate at very low speed during Dry operation or when the unit is monitoring the room's temperature.

During SUPER QUIET operation, the fan will operate at very low speed.

In the monitor AUTO operation, the fan will operate at very low speed.

Doesn't operate at all

Indoor unit

Has there been a power failure?

Has a fuse blown out, or a circuit breaker been tripped?

Is the timer operating?

Poor Cooling or Heating performance

Indoor unit

Is the air filter dirty?

Is the air conditioner's intake grille or outlet port blocked?

Did you adjust the room temperature settings (thermostat) correctly?

Is there a window or door open?

In the case of Cooling operation, is a window allowing bright sunlight to enter?

In the case of Cooling operation, are there heating apparatus and computers inside the room, or are there too many people in the room?

Is the unit set for SUPER QUIET operation?

The unit operates differently from the Remote Control Unit's setting

Indoor unit

Are the Remote Control Unit's batteries dead?

Are the Remote Control Unit's batteries loaded properly?

Water is produced from

Outdoor unit

During Heating operation, water may be produced from the outdoor unit due to Automatic Defrosting operation.


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Can I re-use the piping which is already installed for my old Air Conditioner?


It is not recommended to re-use the same piping and cable for new units as different systems have different piping and electrical requirements.

What happens if piping is less than the minimum recommended length (3 metres / 5 metres)?

If the product is installed with less pipe work than the minimum requirement specified by Fujitsu engineers, noise and/or vibration issues may occur and also the system may not perform as well as it is designed to. Fujitsu will not cover warranty claims for issues caused by units not being installed in accordance with their manuals.

Can I re-use the ducting which is already installed for my old Ducted Air Conditioner?

Ducting is sized and placed according to the house layout and the desired air distribution, as long as the duct work meets the requirements of both the unit and the air-conditioned space then it is fine to keep the old ducting if it is in good condition. This would need to be confirmed with your air conditioning designer and installer for your particular requirements.

How do I choose the best place to install a Wall Mounted Air Conditioner?

Wall mounted indoor units (also known as High Wall Splits) are best positioned high on a wall that has suitable access for drainage. However, there are different installation options which you can discuss with your Fujitsu Air Conditioning specialist.

How do I choose the best place to install a Ceiling Cassette Air Conditioner?

Ceiling Cassettes should be installed into the centre of the room where the air will be able to circulate evenly in all 4 directions. It is not recommended to install Ceiling Cassettes into corners or close to walls unless this has been considered in the design.

Can I put a cover over the front of my outdoor unit to make it less visible?

The outdoor unit of your split system needs to have adequate clearance around it to ensure it operates correctly. If you would like to conceal your outdoor unit, talk to your installer to see if a louver can be used for your installation.

What is the best location to install the outdoor unit from my Split System?

It is advised to install the outdoor unit in a safe, dry and well-ventilated area. Make sure you meet any local council rules and/or regulations. Keep in mind the location of your bedrooms and of course your neighbours. If you have any questions, consult the installation manual and it will give you a guide as to where to place the outdoor unit.

If I move house can I take my split system with me?

It is possible to take a split system with you to a new home. However the removal of the system must be done by a qualified Refrigeration and Air-conditioning Technician and must be done in accordance with the installation manual of the air conditioner. The warranty is only valid for the first place the air conditioner is installed, so please take this into consideration if you want to move your air conditioner.


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Please download it on our web site or local web site.

Operation manual

Please ask your purchase retailer or dealer.
If you can't inquiry, contact our service in your area.


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Filter, Remote Controller, Controller Holder


Please ask your purchase retailer or dealer.
If you can't inquiry, contact our service in your area.


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