Furnace Circuit Board -- The furnace circuit board controls a variety of functions. It not only handles the regular operation of the furnace, it also monitors the furnace's various safety circuits. Over time, vibrations from the furnace can weaken solder point and cause them to separate. Dirt and debris can cause short-circuits that damage the board. Failure of the circuit board can cause a variety of effects ranging from the fan not turning on to the complete shutdown of the furnace.


Did not realize cost had gone up so much for this service. Two years ago I had furnace and ducts cleaned at my old house and it was under $400. Now the cost is $700 for this house. I will keep looking for someone to offer a lower price, check them out, and have it done. Or will find the paperwork to see who did it before. I liked this article and did learn some things. Thanks.
Demand controlled kitchen ventilation (DCKV) is a building controls approach of controlling the volume of kitchen exhaust and supply air in response to the actual cooking loads in a commercial kitchen. Traditional commercial kitchen ventilation systems operate at 100% fan speed independent of the volume of cooking activity and DCKV technology changes that to provide significant fan energy and conditioned air savings. By deploying smart sensing technology, both the exhaust and supply fans can be controlled to capitalize on the affinity laws for motor energy savings, reduce makeup air heating and cooling energy, increasing safety and reducing ambient kitchen noise levels.[29]
Quality and price should come hand in hand, a too-good-to-be-true price for an efficient air duct cleaning will not give you the quality that you wanted. To make sure you are getting your money’s worth, check reviews of air duct cleaning companies, certifications from industry since this work requires continuous learning due to new techniques and research breakthrough from time to time. Make sure to shop around and get written estimates first.

There is a lot of good, general information in the article. As with anything, the homeowner should do their due diligence in getting enough information to make an educated decision. Should duct-work be cleaned? YES! Does it need to be cleaned annually or even every second or third year? Not necessarily. It all depends on a bunch of variables. You're right that a well designed and balanced system will deliver the right amount of air flow, but sometimes conditions outside the home/business, make it a necessity to get the ducts cleaned. As for mold? NO filter is going to address a mold issue. If you have mold, you have a moisture issue that needs to be addressed. Also, in my 38 years of experience in the HVAC and sheet metal industries, washable filters are one of the reasons ducts need to be cleaned. They are no where near efficient in cleaning/filtering the air to the level that they should.
1). Busy companies: The company is so busy, it doesn’t need the work. It will add 70% to 100% profit, and if the customer accepts the estimate, it will move that high-margin customer to the front of the line. This often happens in the worst heat of summer when overburdened ACs and heat pumps quit and the dead of winter when furnaces give up. This is a good reason to consider pre-emptively replacing your system once it’s about 15 years old and/or has had major repairs.
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]
In reading through all this about duct cleaning, THE ONE preventative measure people need to realize is that a poorly installed HVAC system that is not sealed and air tight to ensure that ALL indoor air passes through a GOOD air filtration system IS THE best means of ensuring your ducts remain clean. Duct cleaning does not now and will NEVER improve an HVAC systems efficiency. Proper maintenance and installation are the key just as improper installation practices allow for dust infiltration into the duct system. I am a state licensed contractor in Texas, and unless people have their hvac system sealed and/or properly installed, duct cleaning is an absolute waste of money. My duct system is 12 years old as is as clean today as the day I installed the system with ductwork. SO before ANYONE jumps on the bandwagon of duct cleaning, get with your hvac professional FIRST.
I have a white gritty dust throughout my whole house. Dust and it comes right back. We have central air. In 2013 had all the air conditioning tubing in the attic replaced. Old ones were completely clean. Why?? Thought dust would be in there. Put everything in plastic containers. Furniture everything is always covered with this. Problem is always there year round. Furnace people said it is not coming from furnace. We built house in 1971. Only started with this @ 19 years ago. Thinking when air conditioning went in. We cough all the time and sneeze. I do not have friends come here because I hate how dirty my house looks.

I’m a heating and air conditioning contractor. I’ve been in the trade for over 15 years. I’ve witnessed numerous duct cleaning projects and talked with many duct cleaners. Duct cleaning as it’s usually promoted is a fraud. Most duct cleaners claim to deliver cleaner air. They deliver exactly the opposite. The studies on duct cleaning prove it, including a May 1998 study sponsored by NADCA and the EPA! The stories are compelling, but they can come up with stories that “prove” anything they want. Internet searches are dominated by results from those who are paid to tell you that duct cleaning is worthwhile. Search a little more and you’ll find the truth.


Heating, ventilation, and air conditioning (HVAC[1]) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics and heat transfer. "Refrigeration" is sometimes added to the field's abbreviation, as HVAC&R or HVACR or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers).
A year and a half ago (fall of 2015) we replaced the furnace and air conditioner. From what we could determine this was the third forced air furnace and second air conditioner unit for the house. As part of the installation, we changed out the two 6″ ducts feeding the second floor with 8″ ducts. The idea was to get more cold air to the second floor in the summer. It worked and for the first time the second floor and first floor temperatures were the same when the air conditioner was running. Of course, to make the system work I close down upstairs duct damper doors in the winter and open them up in the summer.
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.
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!
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):

As one of the duct cleaners that do it right it disgusts me to hear the horror stories some of my past customers have had with the companies using scare tactics, bait and switch schemes, and just plain intimidation to make a fast buck. The Ductz franchise as a whole has gone behind other "duct cleaners" in the last year to the tune of almost three-quarters of a million dollars. All of this expense could have been avoided had the customers been able to do some background research before hiring. NADCA is a great organization and should be a minimum requirement for finding a duct cleaner. Other great questions include "How long does the service take?" (2 techs, 4-5 hours for a small house, 7-9+ hours for a two system house), "Do you clean the entire system including all trunk lines and the air handler (blower motor and evaporator coil)?", "How do you validate the job you have done?" (before and after picture reports work great). Beware of duct cleaners that say their process will solve all your air quality concerns. Duct cleaning is one of several steps to take to rid your home of unwanted dust, dirt, mold, and other allergens.
I took off stars for two reasons. Minus one star for issues trying to use the $50 for $25 voucher I purchased through Yelp. Although there was no minimum stipulated, the office wouldn't take it for the initial $59 diagnostic fee. If I used the 10% off First service that they offer, then they won't let me use the voucher on the actual repair bill.  I was stuck with paying the full $59 diagnostic fee.
I read your article with interest and think it is a good start. One service that is always talked about is fogging ductwork for sanitizing. Many companies offer this service for disinfecting or adding a clean smell to the ductwork. Before any chemical or disinfectant is used, please read the MSDS (Material Safety Data Sheet). You might be surprise on what you are putting into the air stream. This is a high profit service and should be explored thoroughly before purchasing,
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 jury is out on whether or not cleaning your air ducts and vents has a significant enough impact to be necessary. A proven connection between immaculate duct systems and air quality in the home has not been made. However, if your vents display any of the signs listed above, cleaning would certainly be in your best interest. Allowing mold, debris and bacteria to fester could create bigger problems down the line. If having your system disinfected is within your budget, you may prefer to take care of these issues rather than ignore them.

"Customer service was great, and the price was in-line with other places, and fast service. We had a whole replacement of the outside and inside. I would have liked to see a better install for the furnace and new thermostat - the new thermostat should have gone where the old one was, and even tho the new furnace was a tight fit, they didn't offer to come back and repair the case molding, or give me a discount on the damage done, and I believe they should have put a disconnect box on the outside of the home, to make it easier for any future repairs needed. Other than that, am very happy with the cooling and heating!"

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