On average, we (Indians in Ontario) receive 3-5 calls per day for duct cleaning services from India. I did get ducts cleaned twice in 25 years. For a newly built house, it should be done as material goes into the ducts. Every year, before turning the heat on, I clean the ducts, using the vacuum pipe or with wet towel. Most of the dust, pet hair, small items get to the ducts from the top floors, not where system is installed. Even in winter months, I open 2-3 windows for air circulation for 15 minutes, specially right after cooking, almost daily. We breath in the same stale air, develop health issues. Also, I have an added air cleaning and fileration system installed. At a low rate, this system constantly cleans the inside air and also that it pulls from the outside. Duct cleaning is a scam, there are other efficient and cost effective methods we can use to purify the inside air.
Preventing against air leakage is great, but the only way to keep dust and debris out of a duct system would be to completely seal off the return-air side of the system, which would render the system useless. Cold-air returns will always pull dust and other particles into the system. A high-MERV rated filter is definitely a good idea, but it does nothing to keep the return side of the system clean. Definitely agree though to use foil tape to seal seams, etc. Duct tape dries out over time and as it does can actually add more particles to the air.
The HVAC installation costs below are based on residential installations only, and are priced for a single unit. Two units should be about twice the price. “Tim, shouldn’t there be a discount?” If people start giving you discounts, they are probably charging you too much to begin with.  That’s our philosophy anyway. Twice the parts and time should be twice the price from a fair contractor. The prices listed include component parts (with warranty), labor, and all materials for a complete HVAC installation.
I have lived in Calgary for quite some time now. When I first moved here I couldn’t stand the humidity levels. Its like a desert come winter. When I first moved into my new home, the house inspector insisted I have my furnace and ducts cleaned. I was very sceptical about duct cleaning to begin with. The company I hired came on time and were very respectable from the start. Before mentioning anything they asked me what my concerns were and what issues I was having. They were more concerned about addressing my issues then bringing anything non related up. I ended up going with this company and getting a humidifier installed a couple days later after the cleaning. Its been almost 4 years now that I have been here. The humidifier is working great and the difference is incredible. They took me around explained step by step what they were doing and the reasons they were doing it. With all those other companies out there, I am glad I found them at this site.

Some systems include an "economizer mode", which is sometimes called a "free-cooling mode". When economizing, the control system will open (fully or partially) the outside air damper and close (fully or partially) the return air damper. This will cause fresh, outside air to be supplied to the system. When the outside air is cooler than the demanded cool air, this will allow the demand to be met without using the mechanical supply of cooling (typically chilled water or a direct expansion "DX" unit), thus saving energy. The control system can compare the temperature of the outside air vs. return air, or it can compare the enthalpy of the air, as is frequently done in climates where humidity is more of an issue. In both cases, the outside air must be less energetic than the return air for the system to enter the economizer mode.

Engineers have pointed out some areas where efficiency of the existing hardware could be improved. For example, the fan blades used to move the air are usually stamped from sheet metal, an economical method of manufacture, but as a result they are not aerodynamically efficient. A well-designed blade could reduce electrical power required to move the air by a third.[28]

So, naturally I respond with, “you don’t tell your doctor which medication to prescribe you, do you?” The point is, on the residential level, who you get to install your HVAC unit is far more important than which unit you choose.  Keep your options open and let your HVAC contractor make a few recommendations – that’s why you spent time finding a reputable contractor!
Multiple inventions within this time frame preceded the beginnings of first comfort air conditioning system, which was designed in 1902 by Alfred Wolff (Cooper, 2003) for the New York Stock Exchange, while Willis Carrier equipped the Sacketts-Wilhems Printing Company with the process AC unit the same year. Coyne College was the first school to offer HVAC training in 1899.[12]
I was told that 15 out vents would be cleaned and one main vent. the guy came over and gave me an estimate of $500. I had acquired a groupon for $49. the guy said just doing the out vents and one main vent would accomplish nothing. Now I am in dispute with the groupon people for a refund which they won’t give and have to go ahead and waste the money and let them do it. Is their doing the 15 outvents and one main one going to accomplish anything?

To qualify for a tax credit from the federal government, you must save the manufacturer's certificate from your system. The IRS won't require the certificate at the time you file your federal tax forms, but they recommend keeping it with your records in case of an audit. It proves that you purchased a qualifying product. The government offers tax credits for:

Many homes have a forced-air HVAC system. Both the heating and the central air conditioning units share a ductwork system where they either push in or pull out warm or cooled air. There are also heating and cooling systems that don’t require ductwork — such as ductless mini-splits — but work on the same principles of heat exchange. The national average to hire an HVAC specialist is $2,920-$3,670, with costs varying depending on the work you need done and the equipment you are installing.

If there is stuff in the ducts, the fact that it’s laying there and not being blown into the rooms is proof positive that it is hurting no-one. The 5-6 exceptions you cite in this article I’ll buy, but only with the caveat that at least some of those could have been avoided by proper protection (during remodeling for example) – and if asbestos/lead/whatever winds up in your ducts- the remodeling contractor should be the one paying to remove it.

From furnace installation and heating system installation to air conditioning installation and central air installation, Lowe’s has all your HVAC installation needs covered. Lowe’s will coordinate with independent air conditioner installation professionals to make installing central air a breeze. So stop worrying about how to install an air conditioner and contact Lowe’s to help with your air conditioning install.
They work less jobs, thus increasing profits – think about it…if they got only half of the jobs, then they only pay half of the money required to pay employees, expenses, etc., but still have the same amount of net profit. In fact, if you do the math, they actually make more profit that their competitors do…twice as much, once you factor in their savings form only doing half of the jobs at the same amount of profit (Total Revenue – (half the normal expenses) = twice the profit). In other words, they save money by doing half of the jobs as others, for the same profit, thus increasing their overall profits.

In addition, the black dust was found in most of the heat registers. He could rub it off on his fingers but did nothing but spray compressed air on it which didn’t make it disappear since it wasn’t loose. Also, in the register in the basement he described the black dust as being oily. The reality of that situation is that I had the AC on until the morning of the service and minutes after he snaked the hoses in my back door it started raining. The basement register had condensation from the humidity all over it. It was not oily but wet. He asked for an old towel and wiped it out. Never saw anything so black – because I never had to clean soot. That is what I have in my ducts. Soot from years of the old coal furnace.
Compressor -- Compressors are outdoor components in your system. The compressor is the pump that circulates the refrigerants through the air-conditioner. You can hear it when it's running so you'll know if it's working just by listening. If it starts getting louder, your compressor is about to fail. If it makes no sound when it should be on, it has already failed. Compressors fail for a number of reasons. Most often they fail due to strain from another failed part such as the fan motor. Electrical storms can also damage compressors. If the sound from the compressor gets louder or if you see a decrease in performance, you should have your compressor checked. A failed compressor will not heat or cool your house.
Refrigerant Metering Device -- Every HVAC system has one of these, and heat pumps have two. They regulate the amount of refrigerant going through your air-conditioner. If it fails, either too much or too little refrigerant will course along the lines and either not perform well or will overwhelm the compressor and cause it to fail. A total failure of this component will result in a complete loss of operation.
I hope that those customers you have with breathing problems don't follow your advice too closely. You are doing them a disservice. Dirt in your ducts does not always stay there, depending on what the contaminants are. I bet you tell your customers not to worry about mold either- just to kill it with bleach. Educate yourself before opening your mouth- You may kill someone someday with your opinion.
After major damage to a small addition on our home was damaged in the windstorm in May, the insurer’s preferred vendor sanded drywall without taping off the area. They relied on heat from the furnace to dry the mudding compound. They claimed they shut the furnace off while sanding and regardless of whether they did or not, they never cleaned up the drywall dust before turning the furnace back on. I now have drywall dust everywhere and my husband took photos to verify our concerns. They even sanded right above a cold air return. Vents were never covered either. The same company that created this mess is cleaning my ducts today. They have refused to clean the furnace. Their are health concerns for my almost 85 yr old mother who resides with us. I’ve tried 3 times in the last 7 days to escalate to a manager and they will not return my call. They just keep sending it back down to my adjuster. There are many other issues we’ve encountered since May as well. This is a major insurance company who has the resources to fix this mess but refuse. Please help!
How exactly do you expect to kill or remove mold without it ? You can’t even clean your hvac systems coils without moisture of some type ,if you use a steam cleaner you can literally clean the whole system minus the electronics . You should do more research and possibly talk to people who do the work before posting , but don’t listen to me i only have a class A contractor license ,epa license , install /repair hvacs , rent and flip houses for a living .
Do not hire duct cleaners who make sweeping claims about the health benefits of duct cleaning — such claims are unsubstantiated. Do not hire duct cleaners who recommend duct cleaning as a routine part of your heating and cooling system maintenance. You should also be wary of duct cleaners who claim to be certified by EPA. Note: EPA neither establishes duct cleaning standards nor certifies, endorses, or approves duct cleaning companies.