Air duct cleaning service providers may tell you that they need to apply a chemical biocide to the inside of your ducts to kill bacteria (germs) and fungi (mold), and prevent future biological growth. Some duct cleaning service providers may propose to introduce ozone to kill biological contaminants. Ozone is a highly reactive gas that is regulated in the outside air as a lung irritant. However, there remains considerable controversy over the necessity and wisdom of introducing chemical biocides or ozone into the duct work.
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.
My mom just received service from this company. She paid $609 to have her frion replaced. After two uses the AC stops working. A young rep comes out to the house again and notifies her that her entire AC unit and furnace need to be replace for just shy of ten grand, though when her frion was refilled she was told that her system should last another five years. When they came back to tell her how her entire system needed to be replaced, they were generous enough to offer her a $300 credit on the nearly $10,000 estimate of replacing the entire system that was working fine until they touched it. My best assumption would be that there is a mishap with the system is due to their negligence. Id suggest using another company other than these scam artists.

An air conditioning system, or a standalone air conditioner, provides cooling and humidity control for all or part of a building. Air conditioned buildings often have sealed windows, because open windows would work against the system intended to maintain constant indoor air conditions. Outside, fresh air is generally drawn into the system by a vent into the indoor heat exchanger section, creating positive air pressure. The percentage of return air made up of fresh air can usually be manipulated by adjusting the opening of this vent. Typical fresh air intake is about 10%.


The bottom line is: no one knows. There are examples of ducts that have become badly contaminated with a variety of materials that may pose risks to your health. The duct system can serve as a means to distribute these contaminants throughout a home. In these cases, duct cleaning may make sense. However, a light amount of household dust in your air ducts is normal. Duct cleaning is not considered to be a necessary part of yearly maintenance of your heating and cooling system, which consists of regular cleaning of drain pans and heating and cooling coils, regular filter changes and yearly inspections of heating equipment. Research continues in an effort to evaluate the potential benefits of air duct cleaning.


If you want to get some of the dust and debris out of your ventilation system, you can mix household cleaners like bleach with water, dip a cloth in the mix and then the wipe out the system. This will remove a layer of the spores, which could increase the quality of air a bit and help with the flow of air throughout the house until a pro can come out.
The key to the continued and efficient operation of your heating and cooling system is periodic maintenance. Cleaning the air duct vent system, and servicing you heating and cooling equipment will keep the system operating at its peak performance. Air ducts are cleaned for two reasons. One: to prevent debris from entering furnace and air conditioning components. Two: to prevent debris from cycling through the home. The air duct cleaning contractor needs to employ cleaning methods which successfully removes debris, and ensures that debris does not enter the occupied space. Most contractors can verify the results of the cleaning through video or pictures.

Monday the following week, no phone calls, or follow up.  I call to get an update and am told that they cannot install my system because they don't have time.  I ask what does that mean, one year? One week? Until the end of summer they say.  What does that mean I ask?  They say at the end of September.  I say thank you for wasting 1 month of my time.
Our unit is 16 years old and we've had it checked out recently since it seems to be running excessively. Over all the tech says it is putting out well; it's the correct size, we have no shade and we've been having extreme heat with high humidity. The info you provided is very helpful and will help us make an informed decision when the time comes. Thank you so much.
My 48 yr old house (mine for the last 4 yrs) has considerable dust in the return plenum (fiber duct). I’m remodeling and recently re-sealed the return plenum AND the site-fabbed transition built when the new unit was installed, 2013. The return was leaky no doubt drawing musty, dusty air from the crawl space due to the Red-Neck fab & seal job! Pitiful craftsmanship! It took me 7 hours to fix the new transition piece. Anyway, the dust in the house is the same “color” as whats in the return duct and I’m getting way too much & too often in the house. I’ve also cleaned my coils, which were not that dirty.
I purchased a Groupon for cleaning of unlimited air ducts and one return vent for $39. I should have checked into their hours first because they only offer services during normal business hours. So, with no evenings or weekends available you have to take time off work. I asked Groupon for a refund when I realized this and they refused because it wasn’t within the three day window. Then they didn’t even show up or call for the appointment. I called them after they were an hour late and they were going to call the local dispatch office and have them call me back within 15 minutes. I did not receive that call. I called again and was told I would get a call back from a manager. That didn’t happen either. So I asked Groupon for a refund again and they gave me Groupon bucks. When the survey came asking if I was satisfied with the Groupon customer service I said no, I want real money. I got my real refund the next day. Seems to me Groupon should stop dealing with these companies.
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.
It seems all the average costs for a complete heating and cooling system replacement I've found on websites are usually at least 1/4 less, mostly half lower, then quotes I've gotten from companies. The worst quote I got was from One Hour Heating & Air Conditioning (the company with the Mike Rowe commercials), for over $15,000! I finally settled on a Carrier dealer, for $10,700 & I'll get $950 of that back in energy co rebates eventually. The company I went with's basic system would have been around $8800 (the only one that sorta matched up with web avg cost). They did all the correct planning as far as I could see, not like One Hour, who just showed me a price guide for the same size units already in place. And they do all the rebate paperwork and submit it to the energy co, One Hour never even mentioned possible rebates! Plus Carrier gets above avg reviews. I would have greatly liked a price under 9 grand, but this company got me 0% APR financing, so at least nothing out of pocket. My advice is stay away from national chains, and shop around with local area companies. Of course, One Hour says local companies will fold before you need warranty service lol. For their cost, there should be a technician living in his work van outside my house hahaha.
CIBSE publishes several guides to HVAC design relevant to the UK market, and also the Republic of Ireland, Australia, New Zealand and Hong Kong. These guides include various recommended design criteria and standards, some of which are cited within the UK building regulations, and therefore form a legislative requirement for major building services works. The main guides are:

The key to the continued and efficient operation of your heating and cooling system is periodic maintenance. Cleaning the air duct vent system, and servicing you heating and cooling equipment will keep the system operating at its peak performance. Air ducts are cleaned for two reasons. One: to prevent debris from entering furnace and air conditioning components. Two: to prevent debris from cycling through the home. The air duct cleaning contractor needs to employ cleaning methods which successfully removes debris, and ensures that debris does not enter the occupied space. Most contractors can verify the results of the cleaning through video or pictures.

In the United States, HVAC engineers generally are members of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), EPA Universal CFC certified (for installation and service of CFC HVAC devices), or locally engineer certified such as a Special to Chief Boilers License issued by the state or, in some jurisdictions, the city. ASHRAE is an international technical society for all individuals and organizations interested in HVAC. The Society, organized into regions, chapters, and student branches, allows exchange of HVAC knowledge and experiences for the benefit of the field's practitioners and the public. ASHRAE provides many opportunities to participate in the development of new knowledge via, for example, research and its many technical committees. These committees typically meet twice per year at the ASHRAE Annual and Winter Meetings. A popular product show, the AHR Expo, is held in conjunction with each winter meeting. The Society has approximately 50,000 members and has headquarters in Atlanta, Georgia.


In variable climates, the system may include a reversing valve that switches from heating in winter to cooling in summer. By reversing the flow of refrigerant, the heat pump refrigeration cycle is changed from cooling to heating or vice versa. This allows a facility to be heated and cooled by a single piece of equipment by the same means, and with the same hardware.
PickHVAC Tips: Electricity resistance heat is the most expensive heating type. You don’t want one of these unless you’re heating less than 30 days per year. The upfront cost of an electric furnace is much lower than the cost of a gas furnace. However, operating costs are two to three times higher. If winters are cold where you live, you’ll waste your upfront cost savings in just a few years of high electric bills.
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.
With today’s consistently rising energy costs, improperly sealed windows, ductwork, and poor insulation can pose serious problems for many home and business owners in Arkansas. Wilson's Heating & Air Conditioning provides complete HVAC system servicing including sales, installation, maintenance and repair, and offers numerous practical solutions that will reduce your energy costs.
R-22 Freon is being phased out & isn't readily available. So the service company may only purchase as needed and the lack of availability would make their cost high. But, as long as they can get it, whatever the cost, unfortunately, is less expensive than replacing the A/C. Which will be the case eventually since it's no longer manufactured or sooner as in my case with a not so old a/c that sprang a leak, that would have been just a repair, but since it uses R-22 the whole unit has to be upgraded(replaced).  
For more than 60 years Stanley Steemer has been perfecting our hot water extraction method to clean carpet with unparalleled results. Take control of the environment in your home and enjoy a cleaner, healthier living space for your family. Every carpet cleaning is Certified to remove an average of 94% of common household allergens. We remove the dirt you can see and the allergens you can't. 
As I type this, I am having my ducts cleaned. About 30 including returns and the furnace. $543.00. I am watching the team do it and can see the clear vacuuming tubing and how dirty it has become. I like the gentleman’s comment on “stick your head in your vacuum and breath”….I get it. The team showed me the machine and it’s filtration system…and they will show me it again after the cleaning. However, like I said before, I am actively seeing the tubing that is clear before they start and how dirty it is once they begin and continue cleaning. Reputable company and not a “fly by night” coupon service. People don’t be so cheap, that is your problem.
A little simple math can help determine the size system you need. A rule of thumb is 20 BTUs per square foot. So, a 500 square foot room would need 10,000 BTUs to cool or warm it efficiently. This assumes that you live in a temperate region and have adequate insulation with no energy loss. In the real world, all units have some degree of energy loss. This is reflected in an HVAC system's SEER rating for cooling and AFUE rating for heating.
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!
Unfortunately, manufacturers and contractors don’t publish this information…it’s a secret. Why? Who knows…but we have access to a full contractor pricing database of 1,000’s of different units in our online HVAC installation cost calculator, so let’s choose one for our example calculation. We’ll go with Carrier equipment, since our readers always bother us about them (despite us telling them that they are overpriced):

If the condenser coils are clogged, the compressor can overheat and shut down. You'll experience intermittent periods of minimal cooling, followed by no cooling. Even if you're “sure” the condenser coils are clean, clean them again. Turn off the power. Flip the air conditioning service and furnace circuit breakers in your main electrical panel to the “Off” position. Next, turn off the power switch right at the furnace or air handler. Then yank the disconnect block (Photo 1) and clean the condenser coils (Photo 2). If the air conditioning service still doesn't work properly after you've cleaned the condenser coils, installed a new filter and opened all the supply vents, proceed with the following repairs. Your AC won't work fully unless you do this.
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