How often you should clean your air ducts depends on your situation. If you or someone in the home has asthma or is acutely allergic to certain airborne materials or pollen, regular duct cleaning may be helpful. The Environmental Protection Agency doesn’t have an official position on the necessity of air duct cleaning unless the ducts have been contaminated by rodents, insects or mold, or you are aware of particles blowing out through the vents. The EPA recommends you have your air ducts cleaned on an as-needed basis. The National Air Duct Cleaners Association (NADCA) suggests having air ducts cleaned every three to five years.
Most modern air-conditioning systems feature a dehumidification cycle during which the compressor runs while the fan is slowed as much as possible[citation needed] to reduce the evaporator temperature and therefore condense more water. When the temperature falls below a threshold, both the fan and compressor are shut off to mitigate further temperature drops;[clarification needed] this prevents moisture on the evaporator from being blown back into the room.[citation needed] When the temperature rises again,[clarification needed] the compressor restarts and the fan returns to low speed.
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.
Air conditioners often use a fan to distribute the conditioned air to an occupied space such as a building or a car to improve thermal comfort and indoor air quality. Electric refrigerant-based AC units range from small units that can cool a small bedroom, which can be carried by a single adult, to massive units installed on the roof of office towers that can cool an entire building. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants (chemicals which remove moisture from the air) and subterraneous pipes that can distribute the heated refrigerant to the ground for cooling.[2]
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.
With the split system, the evaporator coil is connected to a remote condenser unit using refrigerant piping between an indoor and outdoor unit instead of ducting air directly from the outdoor unit. Indoor units with directional vents mount onto walls, suspended from ceilings, or fit into the ceiling. Other indoor units mount inside the ceiling cavity, so that short lengths of duct handle air from the indoor unit to vents or diffusers around the rooms.

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.
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:

Summers in Portland and The Dalles can be the absolute best time of year or pure torture.  Your cooling system makes the difference. Take advantage of perfectly maintained temperatures, superior dehumidification, unprecedented energy efficiency, and outstanding reliability with quality air conditioning products and services from Sky Heating & Air Conditioning.  We protect the enjoyment of your home with precise installation, system replacement, seasonal maintenance, and prompt repair.  Our skilled AC technicians are always on call 24 hours a day, 7 days a week, providing Emergency Service and protecting the value of your investment.  Every project is answered with a dedication to customer satisfaction that has earned us an A+ rating from the Better Business Bureau. Contact Sky Heating & Air Conditioning for air conditioning service in The Dalles and Portland, OR.  
If summertime temperatures leave you hot under the collar, you’re not alone. More than 75 percent of U.S. homes use air conditioning, and 90 percent of new homes are equipped with central air. And eco-conscious consumers will be gratified to know that today’s air conditioners are more energy-efficient, which means they cost less to run while keeping you cool and comfortable.
The selection of the working fluids (refrigerants) has a significant impact not only on the performance of the air conditioners but on the environment as well. Most refrigerants used for air conditioning contribute to global warming, and many also deplete the ozone layer.[59] CFCs, HCFCs, and HFCs are potent greenhouse gases when leaked to the atmosphere.
Keep your home comfortable all year round with Keep your home comfortable all year round with this high quality and efficient 14 SEER central heating and cooling heat pump system. This system is ideal for new or replacement residential or commercial applications and consists of the outdoor condenser indoor air handler with evaporator coil heat strip and 30 ...  More + Product Details Close

The use of CFC as a refrigerant was once common, including the refrigerants R-11 and R-12 (sold under the brand name Freon-12). Freon refrigerants were commonly used during the 20th century in air conditioners due to their superior stability and safety properties. When they are released accidentally or deliberately, these chlorine-bearing refrigerants eventually reach the upper atmosphere.[60] Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine radicals catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst until it binds with another radical, forming a stable molecule and quenching the chain reaction.


As a Carrier Factory Authorized Dealer and President’s award winner, we specialize in world-recognized, award-winning, and technologically advanced heating, cooling and air quality products. From air conditioning and heat pumps to furnaces and boilers, you’re going to benefit from increased energy efficiency, decreased sound levels and innovative features that make everyday life easier, more enjoyable and far more comfortable. We provide FREE estimates and flexible financing opportunities. Our goal is to maximize value, sustainability and long-term customer satisfaction.
Honesty and integrity go a long way with me also pricing was very fair.....A-ok gets it done.... My a/c just stopped working after 12 a.m. I called 3 companies and no one was able to come out till the morning. I couldn't wait till morning due to the fact I have elderly people living with me. so I call A-ok and Tyler was the tech on call for the night. He was super helpful and friendly. Tyler was a few counties away but made the call to rush to my home after 12 am. And fix my unit. It was getting pretty hot inside my house. Turns out it was just a fuse that went bad. He was able to correct it in minutes. I'm thankful Tyler is a honest young man. He could have said anything to run up the bill but he didn't... it was just a blown fuse. I high recommend A-OK for service needs. The pricing was fair and matched up better than everyone else.... the difference which is huge was Tyler came out to do the repair where as every other company wanted me to wait till the morning. Thank you Tyler for getting my unit back in order and I'm happy to say they have my Business going forward....

Contact/Relay -- Relays are electronically controlled switches that activate the various components of your HVAC system. They manage everything from the power going to the motor to automatic dampers, humidifiers, etc. Most of them are controlled by the thermostat. The most common failure for a relay is being stuck in the "open" position. Separated from its assigned contact point, it fails to complete the connection and send the message to whatever it was supposed to operate. This failure usually occurs from use over time. Each time a relay connects and sends its signal, the electrical arcing from point to point eventually causes wear and tear.
As a technical industry, the heating and cooling field is associated with annual advances. New energies make our industry an exciting place to work. Our team thrives on keeping up to date with all changes in the HVAC field. We are here to share our knowledge with each customer. When you are ready to update your HVAC system, we can help you select the ideal system for your home.

Expect exceptional service and superior quality. By consistently meeting rigorous national standards for performance, Deljo Heating & Cooling is distinguished as a Carrier Factory Authorized Dealer. We continue to reach high expectations for ethical business practices year after year. By maintaining all required local licenses, complete insurance & liability coverage, and fulfillment of warranty specifications, we provide Chicago area home and business owners a team of support they can count on.


An important component of natural ventilation is air change rate or air changes per hour: the hourly rate of ventilation divided by the volume of the space. For example, six air changes per hour means an amount of new air, equal to the volume of the space, is added every ten minutes. For human comfort, a minimum of four air changes per hour is typical, though warehouses might have only two. Too high of an air change rate may be uncomfortable, akin to a wind tunnel which have thousands of changes per hour. The highest air change rates are for crowded spaces, bars, night clubs, commercial kitchens at around 30 to 50 air changes per hour.[17]


Ventilation is the process of changing or replacing air in any space to control temperature or remove any combination of moisture, odors, smoke, heat, dust, airborne bacteria, or carbon dioxide, and to replenish oxygen. Ventilation includes both the exchange of air with the outside as well as circulation of air within the building. It is one of the most important factors for maintaining acceptable indoor air quality in buildings. Methods for ventilating a building may be divided into mechanical/forced and natural types.[16]
Our goal is to make you more comfortable in your home. When your furnace, central air conditioner, heat pump or boiler stops working and you need service, call the professionals at BGE HOME. Heating and cooling system breakdowns occur at the most inconvenient times, so rely on our certified, skilled technicians to make the repair quickly and correctly the first time.
In 1995, Germany made CFC refrigerators illegal.[22] DuPont and other companies blocked the refrigerant in the U.S. with the U.S. EPA, disparaging the approach as "that German technology".[21][23] Nevertheless, in 2004, Greenpeace worked with multinational corporations like Coca-Cola and Unilever, and later Pepsico and others, to create a corporate coalition called Refrigerants Naturally!.[22][24] Then, four years later, Ben & Jerry's of Unilever and General Electric began to take steps to support production and use in the U.S.[25] In 2011 the EPA decided in favor of the ozone- and climate-safe refrigerant for U.S. manufacture.[17][26][27]
ISO 16813:2006 is one of the ISO building environment standards.[29] It establishes the general principles of building environment design. It takes into account the need to provide a healthy indoor environment for the occupants as well as the need to protect the environment for future generations and promote collaboration among the various parties involved in building environmental design for sustainability. ISO16813 is applicable to new construction and the retrofit of existing buildings.[30]
An air conditioner cools and dehumidifies the air as is passes over a cold coil surface. The indoor coil is an air-to-liquid heat exchanger with rows of tubes that pass the liquid through the coil. Finned surfaces connected to these tubes increase the overall surface area of the cold surface thereby increasing the heat transfer characteristics between the air passing over the coil and liquid passing through the coil. The type of liquid used depends on the system selected. Direct-expansion (DX) equipment uses refrigerant as the liquid medium. Chilled-water (CW) can also be used as a liquid medium. When the required temperature of a chilled water system is near the freezing point of water, freeze protection is added in the form of glycols or salts. Regardless of the liquid medium used, the liquid is delivered to the cooling coil at a cold temperature.
Get specifics. Contractors who bid on your job should calculate required cooling capacity by using a recognized method such as one found in the the ACCA’s Residential Load Calculation Manual, also called Manual J. An additional reference for assessing ductwork needs is Manual D. The calculations produce a detailed, room-by-room analysis of cooling needs. Ask for a printout of all calculations and assumptions, including ductwork design. Be leery of a contractor who bases estimates merely on house size or vague rules of thumb.
The Rack Cooling Index (RCI) is a metric that measures the percentage of racks in the data centre where the air inlet temperature is at the recommended or allowable level under the guidelines put forth by ASHRAE. RCI (hi) is the metric for racks at the upper limit and RCI (lo) for racks at the lower limit. This metric reveals how uniformly and efficiently a data centre is being cooled.

Once warm air inside your home blows across the indoor evaporator coil, its heat energy transfers to the refrigerant inside the coil. That transfer, in turn, “cools” the air. The refrigerant is pumped back to the compressor where the cycle begins again. The heat absorbed by the refrigerant is moved outside your home while cooled air is blown inside. Moisture that contributes to humidity is also condensed out of the air. Your cooling system is usually combined with your central heating system because they share the same ductwork for distributing conditioned air throughout your home.
Dichlorodifluoromethane (R-12) was the most common blend used in automobiles in the U.S. until 1994, when most designs changed to R-134A due to the ozone-depleting potential of R-12. R-11 and R-12 are no longer manufactured in the U.S. for this type of application, so the only source for air-conditioning repair purposes is the cleaned and purified gas recovered from other air conditioner systems. Several non-ozone-depleting refrigerants have been developed as alternatives, including R-410A. It was first commercially used by Carrier Corp. under the brand name Puron.[citation needed]
Service Experts Heating and Air Conditioning was founded on the basis of providing customers with the best heating and cooling practices in the industry. Since its inception, Service Experts has been dedicated to community, providing the top of the line HVAC products and services in your area. If you want more information about your local HVAC leaders, call us at 866-397-3787 or set up an appointment with us online.
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.
Evaporative coolers tend to feel as if they are not working during times of high humidity, when there is not much dry air with which the coolers can work to make the air as cool as possible for dwelling occupants. Unlike other types of air conditioners, evaporative coolers rely on the outside air to be channeled through cooler pads that cool the air before it reaches the inside of a house through its air duct system; this cooled outside air must be allowed to push the warmer air within the house out through an exhaust opening such as an open door or window.[28] These coolers cost less and are mechanically simple to understand and maintain.
"Very impressed. Returned call within 24 hours. They came out the same day I spoke with them and made the repair within 25 minutes. Very low service call fee. I had another repair service out two weeks earlier and after 3 service calls and the central air still not fixed and temperatures in the high 90's, it was such a relief to have a company identify the problem, have the necessary part with them and fix the problem."
Many disconnect blocks contain two cartridge fuses. Check them before you proceed with repairs (Photo 3). A blown fuse is a sign of a failing part inside the condensing unit. So don’t just replace it and think you’ve solved the problem. Instead, replace the parts we show here. Then install new fuses and fire up the unit. If it blows again, call a pro—you’ve got more serious issues.
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