But Tim, doesn’t this mean that a less-than-honest air conditioning company can just charge what he wants and say that it’s a difficult job? No. You see, dishonest contractors, typically, aren’t the brightest people (I figure if you’re still reading this, you’re warming up to me so I’m taking off the training-wheels). They aren’t smart enough to take difficulty into account, and will probably get confused if you ask them about it. They will tell you things like, “that’s how much the unit costs,” or “California has a new law that magically adds $5,000 to the price.”  Trust me, follow your gut, and you’ll be able to tell who the honest contractors are...or just use one of our ASM-approved contractors.

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]
There are multiple reasons to replace your HVAC system. If you have built additions onto your house, you may find your old system no longer meets the requirements for the new dimensions. Perhaps a new technological breakthrough has provided features that will improve your comfort and air quality. Most often, however, you need to replace your system because it no longer works properly.

Before you choose any duct cleaning service provider, interview as many service providers as you can. Ensure that the service provider is certified by the National Air Duct Cleaners Association or NADCA. Make sure that they hold a good standing in the Better Business Bureau and have all the necessary certifications and license. Be clear about their terms of service. Make sure they have the right equipment to do the job. It is best to go for a company that has been tried and tested successfully by any of your acquaintances or opt for a service provider that has been in the business for quite some time.


DIY: We don’t recommend a DIY approach. Depending on the system, working with gas, electricity and refrigerant create dangers. Beyond that, it is essential that split system components be selected for compatibility. DIY installation of an HVAC system will void the warranty of most brands. The manufacturers won’t stand behind the warranty when anyone other than a certified installer does the work. This is true since improper installation is the main cause of poor system performance and mechanical breakdowns.


Within the construction sector, it is the job of the building services engineer to design and oversee the installation and maintenance of the essential services such as gas, electricity, water, heating and lighting, as well as many others. These all help to make buildings comfortable and healthy places to live and work in. Building Services is part of a sector that has over 51,000 businesses and employs represents 2%-3% of the GDP.
Many disconnect blocks contain two cartridge fuses. Check them before you proceed with repairs (Photo 3). A blown fuse is a sign of a failing part inside the condensing unit. So don't just replace it and think you've solved the problem. Instead, replace the parts we show here. Then install new fuses and fire up the unit. If it blows again, call a pro—you've got more serious issues.
PickHVAC Tips: Oil burns dirty, so it is important to have your plenum and ducts checked to see if they should be cleaned when replacing an oil furnace. If you don’t clean the plenum and ducts when replacing the furnace, the new furnace might not run as efficiently and comfortably as possible due to restricted airflow. This can also reduce the oily smell sometimes associated with oil furnaces.

Duct cleaning is a band aid, like washing you hands is. Under your description, why wash your hands more than once? If it gets cleaned once, it shouldn't get dirty again. Well that is, unless they touch something dirty. Keeping your hands completely clean is virtually impossible. Same as keeping dust out of your home. You clean your ducts and over a 3-5 year span they get dirty again. Also, duct cleaners are not licensed but should be certified by NADCA(National Air Duct Cleaning Association).
Filtration systems -- A second-stage filter is sometimes inserted & used to remove particulates such as pets, smoking or cooking, as well as other odors, gases, and VOCs (volatile organic compounds). A HEPA filter is also available to remove spores, pollens, bacteria and lung-damaging particles. There are also systems that use ultraviolet (UV) light to protect against bacteria and germs.
Good article, but it fails to point out that leaky return-side ducts could be drawing dust and allergens into the duct system from the enclosed spaces in which they run, e.g. between walls, below floors, attic. So duct cleaning may only be a temporary solution. The homeowner can get a home energy audit -- free in many states -- to determine if they have significant duct leakage. An Aeroseal dealer may be able to effectively seal up the duct system without needing to tear into walls etc to get to the ducts.

HVAC professionals in the US can receive training through formal training institutions, where most earn associate degrees. Training for HVAC technicians includes classroom lectures and hands-on tasks, and can be followed by an apprenticeship wherein the recent graduate works alongside a professional HVAC technician for a temporary period.[33] HVAC techs who have been trained can also be certified in areas such as air conditioning, heat pumps, gas heating, and commercial refrigeration.[34]
DIY: Most DIY installations go smoothly. The major brands have compatibility checkers to see which of their models will work with the wiring your old thermostat is using. Potential problems involve the need for a C-wire, or common wire, when the existing bundle doesn’t include one. There are solutions discussed in our Thermostat Buying Guide, linked to below.
I can't believe the number of people saying a good properly installed central heating system never needs to be cleaned. Maybe they live in hermetically sealed cells? One look into a cold air return and you can see that it definitely needs periodic cleaning. The air in the house "always" has some dust in it and that's where it ends up. We just had ours cleaned and I saw what came out of it, disgusting. But always ask if they use the "air whip" to sweep/beat the inside of the metal duct. If not, don't bother. These folks used a little whip on the end of a pressure hose and swept the entire length of all the ducts. I have lighted bore scope that allowed me to see into the duct after he was done and it was spic and span. But do change your filters often, 2 or 3 times a year.

Once on the scene, trained Sears professionals utilize powerful, truck-mounted equipment to clear your air ducts of dust, debris, pet dander, allergens, and grime. Our powerful air duct cleaning suction equipment vacuums out years of accumulated dust from your air ducts, leaving them clean and clear. Once finished, our technicians remove all equipment and make sure that your ducts and HVAC unit are restored to their best condition. For continued protection against dirty air ducts, your service technician may suggest a variety of air purification products.
Installation: Replacement is quite easy, especially when an old refrigerant line set can be used. If the set is worn, it’s much better to pay the extra $400-$600 to replace it rather than risking it leaking later. When your AC loses refrigerant, you lose your cool air and the compressor is at risk of failing. A new installation means installing a coil in your furnace or air handler, running the line set between it and the coil in the condensing unit and adding refrigerant, if needed. Most ACs come pre-charged for 20-30 feet of line. If the line set is longer, a small amount of refrigerant is added.

Hi guys if your not convinced yet that duct cleaning is a waste of time. I’m a HVAC business owner install heaters and air conditioners. Simple facts if you have an old system get a new return air fitted with a filter it will catch all the dirt and dust. If you still have as many do black flecks and stuff coming through it is the lining inside your ducting that has perished. So somewhere you have a hole or very old ducting. If you had rats etc its a hole somewhere. To clean, stick your vacuum in the outlet and push the hose as far as it will go this gets 99% of toys and coins fur and alike. Think about it if the object is not heavy it will come out the duct when unit is on. Service the heaters or air con units but not the ducting. I would go further to say that duct cleaning actually damages the ducting in my opinion.

We use third party data sources to conduct a criminal search, in the state in which the owner/principal of the company is located, for any relevant criminal activity associated with the owner/principal of the business, within the three years prior to such service professional's application for membership in the HomeAdvisor network. HomeAdvisor's third-party vendor uses a national criminal database ("NCD") to screen our service professionals. The comprehensiveness of the NCD varies by state. Please be aware that the reporting in the NCD is particularly limited in the following states: AL, CO, DE, GA, ID, KS, KY, LA, ME, MA, MI, MS, MT, NE, NV, NH, NM, SD, UT, VA, VT, and WY.
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