The liquid refrigerant is returned to another heat exchanger where it is allowed to evaporate, hence the heat exchanger is often called an evaporating coil or evaporator. As the liquid refrigerant evaporates it absorbs energy (heat) from the inside air, returns to the compressor, and repeats the cycle. In the process, heat is absorbed from indoors and transferred outdoors, resulting in cooling of the building.
Once i received a call from a Person he Named Steve and He told me that he is from some like GTA Home services and providing Air duct Cleaning in around 105$ and i booked an appointment because he convince me in very will mannered so i agree the services i placed an order and i don't think that they guyz do a great job as he describe but they do same as he told me on phone i'm just surprised that they do a great job and they provide me free inspections of furnace and A/C as well and they really do a great job and they don't waist my money and time. thanks Adam Stevenson and GTA home service Team.
If the system is sealed air-tight and a really good filtering system is in place then you should NEVER have to clean your ductwork. Most dust people see in their homes (on beds furniture etc....) is broken down insulation that is being blown into the home from the attic (venturi effect) where the duct bucket (box etc...) is not sealed at the sheetrock ceiling. On the return side, ANY leaks in the ductwork will pull hot attic air and dust into the system, clogging up everything.
They are also often harder to install. A proper location on the roof must be selected that can support the weight of the unit. Then a platform must be built and a drain pipe for the unit must be run along the roof to avoid problems with mold and corrosion. A crane must be used to lift the unit onto the roof while a team guides it into place and hooks it up.
Cost Factors: The size of the unit, its efficiency and it’s single-stage, two-stage or variable-capacity are the top cost factors. Features like communicating technology and improved dehumidification performance also affect the price. Learn more about communicating technology here including the pros and cons, before being agreeing to a communicating system.
The AC contactor (relay) and start/run capacitor(s) (see illustration below) fail most often and are inexpensive. So it's a safe bet to buy and install those parts right away, especially if your air conditioning service unit is older than five years. The condenser fan motor can also fail, but it runs about $150 — hold off buying that unless you're sure that's the culprit.