Q. I'm living in Shenzhen, People's Republic of China. I live on the 9th floor of our 34 floor apartment building, and just had to have our external air conditioning serviced. I was alarmed and amazed as our air conditioning technician tied a rope around himself, and then went out the window to the external air conditioning unit to give it a dose of freon (as I held the rope!). My gf asked, what do they do in the USA?

A. In the USA buildings have central Air-Conditioning and the equipment is usually located on the roof of the building.

Q. Please anyone know the estimate? I have no idea and interested in getting central air conditioning system for my home...tks!

A. Trane and Carrier=You pay for advertising. I just bought a 3 ton Goodman for $1200 installed, outside unit only. Entire central air system with inside ducts, etc.: who knows.

Q. The air conditioning in our house went out over night & last time it happened (about a month ago) we changed the filter & it worked again just fine. So, we changed the air filter agian, but this time no luck. it's not sucking in air where the filters go, any suggustions -- besides calling someone over to repair?

A. Either your fan/blower isn't working, or for some reason it isn't trying to run. Check breakers, and fuses. thermostat setting.

Q. Unit is only 5 yrs. old, not sure if I'm quoting right I had about 5lbs. of pressure they took it up to 60-70 I believe.

A. Average range $175- $250. unless there is a leak on the line. than it's more.

Q. The recent problem seems to be related to the outdoor cooling fan. The air conditioning system seems to be working properly, but there is a loss of cooling of the air coming from the indoor air conditioning vents. I inspected the outside unit, and yesterday the cooling fan was stopped with a humming/grinding sound. The capacitor looked good (no bulging), but I'm not an electrician and I have no way (or the knowledge) to test voltages and amperages and such. Anyway, I blew on some dust/dirt/cobwebs around some of the wires, and started the system back on and the fan moved at normal speed and the system worked and cooler air came out. However, today, the indoor temperature wasn't maintained and I went outside and the cooling fan was running much slower (but it was running). After I turned off the system, I felt the metal cover of the outside unit, and it was very hot, and it seemed that the source of the heat came from directly above the cooling fan motor. Please contact me!

A. Replace your outdoor fan and while your at it replace the capacitor and everything will be fine. But turn your unit off untill you get it fixed or you'll be changing a compressor or buying a new unit.

Q. I just got the ducts in my house cleaned out to get rid of pet dander and help me breathe better. The air conditioning is running great now and seems cleaner to breathe in. The only problem is that there is a loud humming noise coming from the big vent on the wall. It only comes from this big vent, and does not resonate from any of the vents on the ground. The big vent is not the original big vent; my contractor replaced it after the ducts were cleaned because the old big vent was dirty. My contractor says the noise is a result of the air running so openly now, but I'm having a hard time buying that. I think it is the replacement vent vibrating when the air pushes through it. Any thoughts? I'm pretty sure he threw away the old big vent.

A. Call him back and tell him your not satisfied.Lining the duct with duct insulation should help.I think your right about the vibration.

Q. I just moved into a new home that had never had the ducts cleaned. The house is a ranch with gas forced air heat on one zone with about 9 vents. I found this company on a coupon for $45 which included unlimited vents and a couple access holes. When the company began their work they found mold and the price skyrocketed from $45 to $1400. Does this sound like a screw job or is that price accurate for mold removal and duct cleaning?

A. Mold removal/remediation is entirely different from air duct cleaning. However, it is not uncommon to find mold in your air ducts. That is why we recommend the Electro Breeze Duct Mount UV kit at http://www.allergy-relief-air-purifier.com/air-conditioning-filters.html. This unit will eliminate mold and bacteria from your indoor air and keep your air conditioning coils clean from mold. You must consider that to remove the mold from your air ducts, the air duct cleaning company is entering into a potentially dangerous situation for their employees. This requires expensive equipment and a person with the skills to do the remediation properly. Now that they have knocked the mold loose, you will need the high efficiency filtration and ultra-violet light of the Electro Breeze DMUV kit to kill and capture the mold spores in your indoor air. I hope this helps.

Q. Thinking about having one installed. Thoughts on cost to install, operating costs vs using the air conditioning? What about leaks around the installation site...hear that from a lot of people that have had them. Thanks for the help!

A. If you need an attic fan and have a vent at one end of a peaked roof, you can have a fan installed there. I did something else too. One fan in the attic blows air down into the house. Another at the other end of the house blows air into the attic. On a cool day, but with a warm attic because of sun load, I circulate air from the attic through the house. Thermostats in the attic and in the house circulate air only when the house is 70 degrees or less AND the attic is at 75 degrees or more. Also I can switch off the one that blows air into the house. On hot days, after sundown, I can blow air out of the house, sucking it in from the cooler air outside.