BEFORE YOU BUY AN AC SYSTEM
Jacksonville's Air Duct Cleaning Specialists
TIPS BEFORE YOU BUY AN AIR CONDITIONING SYSTEM:
Below are some very common questions and answers you should know
before committing to a new Air Conditioning System.
WHAT SIZE SYSTEM DO I NEED?
The type and size of air conditioner you need depends on your climate and cooling loads. If your local Air Conditioning Contractor does his job right he will do what's called a "Heat Load" calculation or he may use the "loose rule" of 400 to 600 square feet per ton (assuming 8 ft ceilings). A Ton is 12,000 BTU's of cooling/heating power. If your home is in direct sunlight and has poor insulation it will be 400 square feet (and sometimes even less) per ton.
On the contrary, a home in shade with good insulation will be about 600 square feet per ton.
Home area (sq ft) # of Tons needed
NOTE: all sizes are based on 500 sq ft per Ton
500 try a window unit
750 1 1/2
750 - 1,000 2
1,000 - 1,500 3
1,500 - 2,000 4
2,000 - 2,500 5
Greater than 2,500 2 or more systems
or zoning required
HOW LONG SHOULD MY SYSTEM LAST?
The average lifespan of a system is from 10 to 15 years.
DO I REALLY NEED A LARGER SYSTEM?
Usually your AC Company will try to sell you a larger system and - they may
be right. This is especially true in developments where the homes were
constructed in quantity and are all the same. The builder probably installed
the least expensive units. Before you go to a larger system you should
evaluate if your cooling/heating is ample now. Even if it is slightly
uncomfortable now it may very well improve with a new system of the same size
as the efficiency rating (SEER) of the new one is probably significantly better
than the old system.
DOES MY DUCT SYSTEM HAVE TO BE CHANGED?
If the Company tries to sell you a larger system you should be aware that the ductwork (what's up in the attic) may have to be changed to accommodate the increase in air flow (CFM). Usually this means that the Supply and Return plenums and trunks must be made larger. This is added expense.
WILL THE COPPER PLUMBING HAVE TO BE CHANGED?
In some cases when you increase the size of the system the "copper" tubing would have to be made larger and if you have this tubing run under the slab or in the attic it will cost a good penny.
WHAT EFFICIENCY RATING DO I NEED?
When you are shopping for a central air conditioner, look for an efficiency rating of 13 SEER or higher. There are systems that go as high as 19 SEER. Most times, the added cost of a better SEER rating will pay for itself in the first
CAN I ADD CENTRAL AIR TO MY FURNACE?
If you have a forced-air heating system or any system that uses air ducts already installed, you may be able to tie an air conditioner coil into existing ducts, depending on their size and your home's relative heating and cooling loads. A good HVAC contractor can do the calculations for you.
THE RIGHT SIZE IS IMPORTANT?
Too large a unit will not adequately remove humidity. Too small a unit will not be able to maintain a comfortable temperature on the hottest days. In both cases improper size will decrease the life of the system. Improper unit location, lack of duct insulation, improper duct sealing, and incorrect refrigerant charge can also greatly diminish the life of the system and overall efficiency .
ON/OFF OR VARIABLE SPEED?
Consider getting a "variable speed" air handler. Instead of the "on-off" operation of other air handlers, the variable speed runs all the time. It slows down to almost nothing when no heating/cooling is needed. A variable speed system tends to keep the indoor humidity more constant. An on-off is the opposite – the humidity is low when the blower is on and goes back up when the blower stops. Also Mold likes to grow in stagnant air pockets in the house
and a variable speed fan will always move air in your home.
QUIET – PEACE OF MIND
There are manufacturers who make noisy systems and those who make quiet systems, both outdoors and indoors. Most of it depends on how well insulated the air handler and condenser are. Look for a unit with quiet operation. Variable speed systems run quieter than on-off.
If you need or want to replace your existing air conditioner's outdoor (compressor) unit, make sure the indoor (blower coil) unit is compatible with the new outdoor unit. A highly efficient outdoor unit will not achieve its rated efficiency if paired with an older evaporator coil. The new unit should be the same number of "Tons" as the air handler and the SEER ratings should be close.
START WITH A CLEAN SYSTEM
A Central Air Conditioning System is a "closed" system. The same air is continually re-circulated within the home. If the Air Handler is replaced with a new one it is highly recommended that the duct system be cleaned. Otherwise, the pollutants lodged in the ductwork from the old system will re-circulate back into the new Air Handler and pollute it also.
GET A SECOND OPINION
If your system is less than 10 years old and the local AC Company pushes you to replace it you should get a second opinion. If it is dirty or has "mold" it might be cleaned for a lot less than replacing it. People love to scare us about mold. Remember no one can look at it and say it is mold. It has to be tested in a laboratory first. On the other hand, if the technician shows you visible signs of rust or
deterioration or the system is not cooling/heating properly, you should consider getting it replaced.