While you consider having your air ducts cleaned, it is a good idea to take a look at your dryer vent. If your dryer vent is clogged, you could be losing energy efficiency. Worse yet, you could be increasing the risk of a house fire. Having your dryer vent professionally cared for costs about $130 on average, and could save you a bit of money and a lot of headaches in the future. For more information on the benefits and cost of having your dryer vent cleaned, take a look at our comprehensive cost guide.
Mitsubishi Electric is a world leader in air conditioning systems for residential, commercial and industrial use. Challenged to create air conditioning systems that provide exemplary performance in the wide-ranging climatic conditions found throughout Japan, our engineers develop amazingly sophisticated yet durable units and systems capable of constant use under virtually any natural climatic condition on earth.
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]

These are the prices for a proper installation from a professional – as a word to the wise, HVAC systems require fine tuning and the custom fabrication of parts during installation to work properly, otherwise they will likely fail prematurely. But there are plenty of people who will do it for cheaper than this, using substandard, used, or stolen equipment (stolen from construction sites and new housing developments). Or, they are using unskilled laborers with no experience, etc. But HVAC is not a “we’ll figure it out trade;” there is a right way and a wrong way to do things. There are just too many predatory companies out there, so be careful. I’d highly recommend not skimping on your HVAC contractor. If you go cheap, you will typically pay more in the long run...and in California, that will be a lot!

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.
If not properly installed, maintained and operated, these components may become contaminated with particles of dust, pollen or other debris. If moisture is present, the potential for microbiological growth (e.g., mold) is increased and spores from such growth may be released into the home's living space. Some of these contaminants may cause allergic reactions or other symptoms in people if they are exposed to them. If you decide to have your heating and cooling system cleaned, it is important to make sure the service provider agrees to clean all components of the system and is qualified to do so. Failure to clean a component of a contaminated system can result in re-contamination of the entire system, thus negating any potential benefits. Methods of duct cleaning vary, although standards have been established by industry associations concerned with air duct cleaning. Typically, a service provider will use specialized tools to dislodge dirt and other debris in ducts, then vacuum them out with a high-powered vacuum cleaner.
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.
Reinstall the access panel and disconnect block. Turn on the circuit breaker and furnace switch. Then set the thermostat to a lower temperature and wait for the AC to start (see “Be Patient at Startup,” below). The compressor should run and the condenser fan should spin. If the compressor starts but the fan doesn't, the fan motor is most likely shot. Shut off the power and remove the screws around the condenser cover. Lift the cover and remove the fan blade and motor (Photo 7). Reinstall the blade and secure the cover. Then repower the unit and see if the fan starts. If it doesn't, you've given it your best shot—it's time to call a pro.

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.

Yes everyone should get all their ductwork cleaned, because it does help, incame down with major allergies and had serval operations on my sinues because of this problem of air quality and dust, plus i almost died from one of the operations, i was suffering so much. Yes you can seal your duct system by buyind duct seal t instead of tape to tape all the corners of the vent system, tape wears out and gets brittle, the sealant you can buy at home depot, and you just brush it all over the connections of your ductwork, it comes in a container and it is like a thick paste and dries making a good seal for your ductwork.
If you believe that the AC's not working or you're getting little or no cold air, check these three things first. Make sure all the registers in the house are wide open. Then be sure the furnace filter is clean. Then go outside and clean off the condenser coils (Photo 2). If several registers were closed or the filter was clogged, the reduced airflow could have caused the evaporator coil to ice up and stop cooling your home. If you've changed the filter and opened all the registers and you're still not getting airflow at the registers, deice the A-coil. Move the thermostat mode switch from “Cooling” to “Off” and move the fan switch from “Auto” to “On.” Let the blower run for at least 30 minutes or until there's good airflow at the registers. Then turn the AC back on to test it. If it works for the next 12 hours, you've solved the problem.