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:
I guess, I will start with saying that air duct cleaning is almost never needed. It is not a scam, but it is certainly something that uneducated homeowners get suckered into. In regards to air flow, a well balanced HVAC system should be able to deliver more than enough air flow. If you are not getting good air flow, it's because your system may be out of balance. Additionally, regular cleaning/changing of the air filters will solve about 95% of your problem. Though you would be surprised how many people either a. don't have a filter or b. don't know about it and leave it there for 10+years. a washable one should be cleaned every 6 months(spring and fall) and a disposable one should be replaced every 3-4 months.
An energy recovery ventilator: This component helps improve the air inside your home by swapping it out with fresh air from the outside. During the winter months when houses are closed up to keep out the cold, the air inside becomes a handy way for colds and flu to infect an entire family. By circulating outside air inside, the health of your family will have a better chance.

The letters in HVAC stand for heating, ventilation and air conditioning. An HVAC system enables you to regulate your home or building’s internal temperature (thermal control) for comfortable living and working. You can bring heat levels down in the summer and up in the winter, keeping your home or office livable year-round. HVAC systems can also help with humidity levels and regulate indoor air quality in a home or office. There are many types of HVAC systems and technologies available.


Prices for central-air HVAC systems will vary. The national average to hire an HVAC specialist is $2,920-$3,670 but can run as high as $5,000 or even $12,000 depending on the capacity you need and other factors. Installing central air conditioning requires an entire system that works together to draw hot air out of your home. The system includes an outdoor unit, which houses the condenser and compressor, and the evaporator coils. If you don’t have an existing duct system, ductwork will need to be installed, which will affect labor and material costs. Leaking or damaged ducts will also need to be replaced.
Indoor Fan Motor -- Indoor fans circulate the air from your house and through the system. Age and dust buildup are the two biggest contributing factors to their failure. When they are starting to fail they will often make noise. Failure of the fan will result in no heating or cooling, and if it is not repaired soon, it can cause other components to fail.
You can adjust for seasons: During the summer, you can have the air conditioner stay off during the cooler morning hours and start cooling the house as everyone gets up and starts moving around. During the winter, you can have your heater stay off while you are away at work and turn on about a half hour or so before you get home so that you are coming home to a nice, warm house.
I was with you until you said avoid steaming cleaning or moisture, there is no way you can remove mold or any other type of biological without moisture. The best way to do this is in fact with a steamer using a commercial disinfectant and a non reactive odor remover so your home smells refreshed and not like a hospital . This is directly contradictory to your article.
I am a service technician [since '92].....and as to double filtering.....I have never recommended it. Granted.....it would be noticeably helpful if the fiberglass filters are the main ones used [which I also never recommend.....as long as system can deliver appropriate air flow with a pleated cotton filter...and any decent service tech can check the air flow for proper cfm]. Any particles small enough to pass through a pleated cotton filter are going to pass through a second filter as well....unless the second filters are so tight that the system is starving for air flow. Has anybody ever accidentally put two filters in their automatic drip coffee maker? What if cars used two fuel filters or air filters? I have told some homeowners to try using second filters at each register [the black thin filter material cut-to-fit....same type used in many window air conditioners].....but I only suggest this when I know they will still get at least 400 cfm per ton of air flow [350 absolute minimum]......as some homeowners know others who say it has helped and it gives them a peace of mind knowing they are doing something to help contribute to a solution, so it HAS to help [even though I think it falls in the "one-born-every-minute" category.....similar to duct cleaning].
I even asked if this is something they don't do, as in services on a Saturday night.  I was told by the receptionist that they do and I would just be ok calling another company if they is not  part of their services. They again assured me someone WILL call me in 10 mins.  Well, unless their definition of 10 mins is never, then they got it wrong as I am still waiting to be called 5 days later.
If no one in your household suffers from allergies or unexplained symptoms or illnesses and if, after a visual inspection of the inside of the ducts, you see no indication that your air ducts are contaminated with large deposits of dust or mold (no musty odor or visible mold growth), having your air ducts cleaned is probably unnecessary. It is normal for the return registers to get dusty as dust-laden air is pulled through the grate. This does not indicate that your air ducts are contaminated with heavy deposits of dust or debris; the registers can be easily vacuumed or removed and cleaned.
I am in need of HVAC ADVICE!! I need a new furnace badly, mine is cracked. I have bought both a 95 % AFUE furnace and a 5 Ton evap coil, I figured it should all be replaced at once for both cost and efficency. My question is with all the negaitive things I have heard about companies ripping you off, what type of price should I pay someone for putting in those two items and bringing everything in my attic up to code? I have been quoted $550 - $ 3300. Wide margin here!! Then of course comes the licencing part!! I know in my heart that I should use a licenced contractor but I have had such bad luck and prices from them that honestly one that was licened in Ga. and just not here in TN and is a tech. which charges 1100 - 2200 less sounds good as so long as I pay some type of Profenial HVAC person say $100 to inspect the work after its done and before I pay them.

Because an air conditioner moves heat between the indoor coil and the outdoor coil, both must be kept clean. This means that, in addition to replacing the air filter at the evaporator coil, it is also necessary to regularly clean the condenser coil. Failure to keep the condenser clean will eventually result in harm to the compressor, because the condenser coil is responsible for discharging both the indoor heat (as picked up by the evaporator) and the heat generated by the electric motor driving the compressor.


I own and live in a mobile home and was told to install a mobile home air condition well I did not want one because the ones for moblie homes are to small,so I install a home air-condidtion and its good for heating and cooling the only thing I do is change is the filter every month or two,What I want to know is how does dirt and dust comes from????
In the middle of summer—even more so in North America—AC repairs are undoubtedly the last thing you want to have to think about. But that won’t keep them from taking place. Fortunately, Service Experts Heating & Air Conditioning is dedicated to completing expert quality AC repair, maintenance and installation throughout the North America area. We certainly don’t want you to be stuck in an uncomfortable home during the hottest days of summer.
If you think duct cleaning might be a good idea for your home, but you are not sure, talk to a professional. The company that services your heating and cooling system may be a good source of advice. You may also want to contact professional duct cleaning service providers and ask them about the services they provide. Remember, they are trying to sell you a service, so ask questions and insist on complete and knowledgeable answers.
I did the $49.00 Groupon they just left. Basiclly all they did was stick a shop vac type hose into the vent supply and one return. I also had the dryer done. the person in charge pointed to the main return inside my humidifier and said it needed cleaning. I explained that I was in facility maintaince and would deal with it myself. After that they finished the vac and didn’t try any other sales pitch. I should have read the reviews before I bought this wast of money and time.
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.

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 were following up on this review and the service call we did for you. We could not find you in our system of ever having gone out to your home. If you could please provide us with the date we were out and the name under which the call was placed that would be great as we would like to see if there is any way we can rectify the situation. We do offer a 100% Satisfaction Guarantee, we have tried to private message you to no avail. Can you please call us at 925-318-4795?  
My best advice has always been that a proper duct cleaning is a valuable investment when moving into a home (new or old), after major renovations and if the ducts have never been cleaned before. It is unlikely that there will be increased air flow, as finding major blockage is unusual, but this will eliminate this as a possible concern if there are air flow concerns. It is also true that the "dust" that is cleared out will most likely never have been distributed through the house unless there has been some work done on the ducts. What is cleared out will be pet hair, toys, clothes, construction material, and biological material (small carcasses and/or feces). Once a proper cleaning is done a follow-up is rarely necessary, but up to the home owners discression.
Tip – Be careful with change-outs. Ductwork deteriorates and sometimes has to be replaced.  It is only if the ductwork is in fantastic condition that you should get a change-out without ductwork (Remember – the ductwork has already been there for 15-20 years, and now it will be there another 15-20…it has to be in good shape). However, many HVAC installation companies like to push change-outs because the ductwork is the most time consuming part of the job, and a change-out is quick, easy money. Realize that it’s only about 15-20% of the jobs that qualify for a change-out, so be careful.
If you don't agree with duct cleaning, fine. If there are some things that HVAC people can do to make the system need cleaning less often fine, but to suggest that I need to GO TO JAIL????? If you need to knock others to make yourself look better....... If duct cleaning is such a scam, why are their governing bodies like NADCA (which I do NOT belong to),several manufacturers of equipment, and national restoration franchises (I'm not a franchise either) who provide this service? I guess the whole world is stupid and only HVAC people are smart. I suppose I am scamming them when I clean puff backs, water damage, fire damage, and clean their carpets too? Or did I wake up one morning and say "ya know, it is great to be a hard working, honest owner operator, but I would love to provide a service that unlike everything else I do is a con and rips off the 90% referral business I busted my butt to earn"
I just had my blower module replaced because my AC coil was frozen over. The underside of my coils had a thick mat of dust because I had never had it cleaned. I cleaned it myself by using a soft brush attachement on a shop vac. The inside of the blower appears to have a white/green growth, and I am sure the ductwork of my 30 year old house can’t be in good condition.
I'm very glad that I found another guy to come replace the circuit board and put it away from the water, fix the water leak, and also find and fix another impending failure.  All of that was for much less than HVAC Service wanted to charge for repair or replacement. The other guy did a great repair, so I'm confident it will not break down again, but if it does, I will not call HVAC Service. Don't get suckered by their Yelp Deal.
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.
The cost to replace a central air conditioner is about $5,000. However, this price varies depending on the size of your home and the difficulty of the project. It can cost as much as $12,500 to replace an AC unit. The labor required to remove and dispose of the old system adds to the price. The size of your home, brand of AC unit and ductwork complexity can all raise the cost as well.
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.
Our heater went out last Saturday, which was a cold day.  Called a few different places and they were the only ones that called back.  The technician Tony came out and after a little testing said the main control board needed to be replaced.  He quoted us a total of $489 which seemed on the high side but it was cold and we were somewhat desperate, so we agreed and paid a parts deposit.

Heaters exist for various types of fuel, including solid fuels, liquids, and gases. Another type of heat source is electricity, normally heating ribbons composed of high resistance wire (see Nichrome). This principle is also used for baseboard heaters and portable heaters. Electrical heaters are often used as backup or supplemental heat for heat pump systems.
No matter what time it is, our experts will have you lounging in the cool air of your home quickly. We stand by our workmanship so much so that we guarantee it in writing for one full year. Our 100% Satisfaction Guarantee* firmly backs our dedication to providing the highest level of air conditioning service in the industry. In fact, Service Experts repairs, sells and installs more air conditioners than any other HVAC company through North America. More people count on us for their home comfort, so you can be certain your home will be back to being cool and comfortable in no time.

BIG THANK YOU for being honest, and advising us that for some reason the fuse/switch was in the reverse position so the AC unit would not properly turn on.   The unit turned back on immediately, and began cooling the house.   And then providing advice that the AC/Heating system needed some TLC, and giving us options to save money by purchasing a maintenance plan that included the filters plus cleaning services since we were already being charged for the service today.
On the other hand, if a service provider fails to follow proper duct cleaning procedures, duct cleaning can cause indoor air problems. For example, an inadequate vacuum collection system can release more dust, dirt and other contaminants than if you had left the ducts alone. A careless or inadequately trained service provider can damage your ducts or heating and cooling system, possibly increasing your heating and air conditioning costs or forcing you to undertake difficult and costly repairs or replacements.
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