AIR CONDITIONER SWEATING

1. HIGH HUMIDITY CAUSES DUCTED AIR CONDITIONER GRILLES TO SWEAT

Air conditioner sweating occurs when humid air in the home makes contact with the cold

surface of the ducted air conditioner grille. Sweating is likely to occur when the air

temperature is below the dew point temperature.

The dew point temperature is the temperature at which water vapour will begin to form

and turn into liquid. Simply put, if the surface of your air conditioner grille is below the dew

point of the room, then moisture will begin to form.

In your roof space where it’s much hotter the dew point temperature is also much higher,

this means that sweating of the ducts and other air conditioning equipment is more likely to

occur.

A clogged air filter impedes the flow of air through the system. This causes the temperature inside the evaporator coil to drop excessively, causing condensation to freeze on its surface. The freezing will reduce the system’s ability to remove heat from the air and eventually cause your air conditioner to break down.

• CHECKLIST TO AVOID AIR CONDITIONER SWEATING
  If you are using your system correctly sweating should not be a problem, if it is we need to
  do some investigating!
  Are all of the windows and doors shut properly (including the rooms you are not
  using)
•  Do you have a minimum of 2-3 zones ON & OPEN?
•  Is the unit set to a reasonable and achievable desired temperature for the day suchas the recommended 24°C? Doing so gives the unit time to cycle/turn OFF for a
  period allowing the grille temps to warm back up and prevent them from getting too
  cold.
•  Are the filters clean? Your filters should be cleaned every three months and more
  regularly during the summer months. Dirty filters mean a colder temperature at the
  grille and an increased chance of your air conditioner sweating. Filters inside air
  conditioners catch dust particles to avoid you breathing it in. If not cleaned regularly,
  your filter can clog, causing it to collect moisture and eventually grow mould. Having
  a clean air conditioner filter allows your family to breathe fresh air all year round.

 

 Has your ducted air conditioner system been serviced?

The indoor coils of your system might be blocked or dirty. Dirty cooling coils means the airflow is restricted,
so you’ll end up with a colder temperature at the grille and again increasing the
chance of sweating.
 Is your roof properly ventilated? The cooler your roof space, the lower the dew point
in your roof. This results in a lessened chance of air conditioner sweating occurring
of the duct and other equipment in the ceiling. To correct this, whirly birds and eve
vents should be installed to lesson the heat load in the ceiling space.

 

2. WHY HASN’T THIS SWEATING HAPPENED BEFORE?
If you take the recent dew point and actual temperatures in Brisbane as an example, the
temperature has reached a top of 34.9C with a dew point of 26C. So, if you were to hold an
object in the air that was 26C, that object would have condensation on it.
The last time this occurred was over 20 years ago

• The cooling coils may be blocked, meaning your indoor unit may need a deep clean.
  We recommend you have this done at least every three to five years. The deep clean
  will ensure that any dirt or grime is removed from the indoor coil & ensures that
  your coils get the correct airflow across them. It also prevents your family from
  breathing in any mould that may be growing on the coils.
•  Your usage habits may have changed, and maybe you are setting the temperature
  lower than 24°C? On warm days, we recommend that you set your air conditioner
  temperature to no more than 10 degrees lower than the outdoor temperature. For
  example, if it’s 32°C outside, your minimum cooling temperature should be at 22°C.
•  May someone be leaving an outside window or door open resulting in your system
  sucking in warm, humid outdoor air?

HOW DO I PREVENT MY DUCTED AIR CONDITIONER SWEATING?
Quite often, homeowners look at their ducted air conditioner installation when dealing
with sweating or condensation issues and while it’s essential to ensure you have a quality
installation, the fact is that most of the time, sweating is rather due to improper use or
maintenance of the air conditioner.

•  Ensure all outside windows and doors are CLOSED. One window is all it takes for
  your system to begin sucking in warm, humid outdoor air which will lead to
  sweating!
• Ducted air conditioning systems are typically designed to cool up to 70% of yourhome at any one time. So, if you have too many zones turned ON, your system will work have to overwork and not cycle off to allow the componentry and grilles to return to room temperature.
•  Make sure you have your desired temperature set to a reasonable temperature, we
  suggest no lower than 24°C in the summer months. If it is particularly hot outside
  you should consider raising the desired temperature a little more while shocking to a limit of 10°C lower than the outside temperature. For example, if it’s 36°C outside,
  ensure your thermostat is set no lower than 26°C. This will reduce your energy
  consumption and also help prevent your air conditioner from sweating.
• Take a look at your zone control system and make sure you have at least two zones
  on
• Make sure you have had your AC system serviced in the last 12 months.