Although HVAC is executed in individual buildings or other enclosed spaces (like NORAD's underground headquarters), the equipment involved is in some cases an extension of a larger district heating (DH) or district cooling (DC) network, or a combined DHC network. In such cases, the operating and maintenance aspects are simplified and metering becomes necessary to bill for the energy that is consumed, and in some cases energy that is returned to the larger system. For example, at a given time one building may be utilizing chilled water for air conditioning and the warm water it returns may be used in another building for heating, or for the overall heating-portion of the DHC network (likely with energy added to boost the temperature).
As a homeowner and an owner of rental property I can tell you that the air ducts sometimes need to be cleaned. If you have had pets or anyone smoking in your home (even a visitor) for any length of time, having the ducts cleaned is really good idea. I had a tenant who did not smoke, but got married to a smoker more than year after moving in. When I realized someone was smoking I had them move out, but the smell was awful. I had the ducts cleaned and sanitized (it was a bit extra). The ducts were shiny like new afterwards. I left the windows open for a few days and we cleaned the place super clean and then replaced the carpets. The duct cleaning was worth every penny because the house looked, smelled, and felt new afterward. I plan to have my own house ducts cleaned again this year as we have two cats. We had them cleaned about 12 years ago and they found building materials in the ducts! If you move into a house that has never had them cleaned, it is good to do it. If you have allergies, clean the ducts to see if it helps. You never know what is in your ducts if you have never had them cleaned.
Free cooling systems can have very high efficiencies, and are sometimes combined with seasonal thermal energy storage so that the cold of winter can be used for summer air conditioning. Common storage mediums are deep aquifers or a natural underground rock mass accessed via a cluster of small-diameter, heat-exchanger-equipped boreholes. Some systems with small storages are hybrids, using free cooling early in the cooling season, and later employing a heat pump to chill the circulation coming from the storage. The heat pump is added-in because the storage acts as a heat sink when the system is in cooling (as opposed to charging) mode, causing the temperature to gradually increase during the cooling season.
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.
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!
We are a hvac company that provide air duct cleaning service are minimum charge $400 to do a proper air duct cleaning with 2 techs avg 3-6 hours that includes sanitizing. I get phone calls all day about the $99 your not going to get much of a cleaning for that price it for them to get there foot in the door and up sell that the only way for them to stay in business. Just from my 15 years of duct cleaning experience.
in response to this reply " should your ducts be cleaned", i have to politely correct the person who answered this. you are not using common sense. first, most of the country uses metal duct work, so for you to say what you did, is wrong. second, the duct system in a house is a circulatory system. that means it draws air into the furnace, it gets filtered, and then it is blown out into the house to heat or cool. So, obviously that air is being brought into the house from somewhere right? Yes, its coming from the outside where there are many allergens and dust particles . For you to says that about whether a duct system is sealed or not, makes no difference. The air is coming from somewhere right? It has to originate from somewhere right? Just look on top of your cieling fan. If there is a bunch of dust up there, then there is obviously a bunch in your ducts. And the duct air is being circulated every day, and every hour through your house. Its simple, dust collects everywhere in your house. Imagine if you never dusted your shelves, or tv? There would be a ton of dust after a while. Well, now think about the air in the duct system. Of course theres gonna be a ton of dust in there. For you to say that it is not benififcial to clean the ducts, is plain ignorant. 90% of the air we breathe is in our household. Wouldnt you want that air to be as dust and allergen free? I could go on for hours about the benifits of duct cleaning, but i just wanted to make a quick point that the person whose says it is not benificial to clean them, is not using common sense. Not to mention, giving the people who clean ducts for a living, a bad name. Use your head .
Had our ducts cleaned late April, 2016. Sodium Chlorite was sprayed into ducts after cleaning. Ever since, we have been bothered with eye and nasal passage irritation because of a “chemical” and “musty” odor. This odor is present whether or not a/c is on.) We are told the sodium chlorite (“EnviroCon, manufactured by Bio-Cide International) is used in hospital and nursing home settings and is not hazardous to health. The air duct company’s suggestion is that they come out and spray even more sodium chlorite…we absolutely don’t want this done! Have had various other recommendations about what we need to have done to remedy our problem. We will be unable to stay in our home if a resolution cannot be found. We’d be willing to replace the ductwork if necessary. (One professional suggested that the cleaning may have “knocked something loose” inside the ductwork and that is the source of the irritant.) This home was built in 1920…no idea when the present ductwork was installed. Any suggestions would be appreciated.
He proceeded to clean each heat register by removing the grille and blasting it with an air pressure hose toward the duct opening thinking that the dust would magically be sucked inside. In one room this caused a ceiling smoke detector to go off because the excess dust fooled it into thinking there was smoke. I put my hand in front of a register he wasn’t working on and could hardly feel a suction. Although we discussed how I open and close damper doors, I realized later that he never checked, opened or adjusted them during the cleaning. He could have closed all but the one he was working on in order to increase suction results. His next step was to blast air into the duct and then attach a “squid-like” device that slapped around inside the duct as far as he could reach. This is important! In a newer house, ducts have long straight runs from the furnace. In older houses like mine they can turn and twist. In fact, the duct we have a problem with runs straight up from the basement inside a wall and turns 90 degrees into a soffit for three feet then into two 90 degree turns to get into the floor joist area for another two feet and finally a 90 degree turn up to the second floor register. When he cleaned this one he could only get three feet into the register with the hose or squid because of the turns. That was the case with most. Hardly what could be described as a decent cleaning.
The fact is if they are dirty why not clean them. As for the Dr’s comment about if it is not disrupted it is fine. As a pet owner sometimes un disrupted pet hair will sit in the corner of a room or under a counter un disrupted but I still clean it when I notice it. Just because you cant see it doesn’t mean you should leave it there to collect more and more. The people that don’t want there air ducts clean either simply cant afford it but would like it done. OR! the crowd that are to cheap.. You should Clean all portions of your house.
I replaced all the ducts but the trunks in my 1969 home when I replaced the horizontal furnace under the house with a gas pack. I got advice from a friend who was an HVAC contractor. I was surprised to find the trunks and other ducts very clean. I replaced the individual runs with flex primarily for the insulation. I wrapped the trunks with insulation also.
2. If air quality is so important and duct cleaniliness is so uncertain, why not adopt doubling filtering; that is, in addition to the existing main furnace filter, add a filter at each air outlet. I understand replacing so many filters would be a burden, but air outlets can be designed for easy filter replacement. The builders and home design engineers should bear responsibility to provide good and low maintenance homes, rather than prioritizing on fancy or costly featuers for homes.
I just bought a home, and the sellers clearly never had the air ducts cleaned. This is, unfortunately, typical of their neglect of the home, so I am not surprised. I was cleaning around the wooden floor registers, and I took the registers off. I found nests of some sort...all kinds of really gross stuff!! I am calling now to schedule duct cleaning for my new home. Anyway, it is very easy to check to see if you really need duct cleaning. Remove the floor registers and use a flashlight if necessary to see if there is dust or debris in the ducting. If these look bad, I'd definitely have the system cleaned. I would also do it after a construction project, after installing a new furnace, etc. I have found that once I had my previous system cleaned, it seemed to remain spotless for 3 years. So it seems that if you just change your filters on time (I have an iPhone alert set for every 3 months), the system will stay clean for years. Hope this helps!
Air duct cleaning service providers may tell you that they need to apply chemical biocide to the inside of your ducts as a means to kill bacteria (germs) and fungi (mold) and prevent future biological growth. They may also propose the application of a "sealant" to prevent dust and dirt particles from being released into the air or to seal air leaks. You should fully understand the pros and cons of permitting application of chemical biocides or sealants. While the targeted use of chemical biocides and sealants may be appropriate under specific circumstances, research has not demonstrated their effectiveness in duct cleaning or their potential adverse health effects. No chemical biocides are currently registered by EPA for use in internally-insulated air duct systems (see Should chemical biocides be applied to the inside of air ducts?).