In a chilled water system, liquid water is pumped throughout the building to “chilled water coils”. Since the liquid water needs to be at a cold temperature, a “cooling plant” is required. The plant is typically referred to as a chiller plant. Vapor compression equipment in the plant, similar to that described in “How does my AC work”, cool water to a cold temperature and pump the cold water to air-to-water heat exchangers where needed.

Shortly thereafter, the first private home to have air conditioning was built in Minneapolis in 1914, owned by Charles Gates.[11] Realizing that air conditioning would one day be a standard feature of private homes, particularly in regions with warmer climate, David St. Pierre DuBose (1898-1994) designed a network of ductwork and vents for his home Meadowmont, all disguised behind intricate and attractive Georgian-style open moldings.[when?] This building is believed to be one of the first private homes in the United States equipped for central air conditioning.[12]

Air conditioning is common in the US, with 88% of new single-family homes constructed in 2011 including air conditioning, ranging from 99% in the South to 62% in the West.[50] In Canada, air conditioning use varies by province. In 2013, 55% of Canadian households reported having an air conditioner, with high use in Manitoba (80%), Ontario (78%), Saskatchewan (67%), and Quebec (54%) and lower use in Prince Edward Island (23%), British Columbia (21%), and Newfoundland and Labrador (9%).[51] In Europe, home air conditioning is generally less common. Southern European countries such as Greece have seen a wide proliferation of home air-conditioning units in recent years.[52] In another southern European country, Malta, it is estimated that around 55% of households have an air conditioner installed.[53] In India AC sales have dropped by 40%[clarification needed] due to higher costs and stricter energy efficiency regulations.[54]

We bought 2 top of the line Lennox HAC for $29,000 less about $3,500 rebates, thinking they would at least last 10 years. Well, after 6 years, the system leaked. We are paying $1,700 to fix that leak. We thought at least it is still under warranty - yes BUT - the warranty covered $15 & the rest we were up for ,even though they advertise 10 year warranty. We are trying to sell & move out of high cost southern Calif & have looked at 20+ places in Arizona. Most of the houses we looked at were built from 1998 to 2005. We asked if the HAC was original & in most case it was - even though the highs were 115 to 120 & the lows 90F - versus where we live the highs run 85 to 95 & the lows are in the 60s. I asked the repairman WHY ours went out at 6 years. He replied that they just do not build them the same anymore. In Arizona, I did not see any Lennox - mostly Trane or Carrier. We had Fujistu in Australia which were fantastic - nothing went wrong in the 9 years we had them. Also, they had full induction motors not like the energy consuming 2 stage motors in Lennox. Maybe the Japanese built Fujusita still builds quality & the warranty is meaningful?
At BJ Heating & Cooling, our dedication to your comfort isn’t limited to five days a week. We are on call to provide the swift, knowledgeable service you need 24 hours a day, 365 days a year. Whether you require scheduled or Emergency Service, expect timely attention and no surprises. We outline the problem, offer upfront pricing, and provide the information necessary to make knowledgeable decisions. Rest assured, our team arrives fully prepared with the replacement parts, materials, and tools to manage a wide range of issues in a single visit.

The most common type of central air conditioning is the split system, which features a large, boxy condenser outside the home and a fan-and-coil system inside, connected by pipes carrying refrigerant. The air is distributed through ductwork. However, not every home can accommodate the ductwork needed to install central air. Split ductless systems are an option for those homes because, as the name indicates, they don’t require ductwork.
Air changes per hour Bake-out Building envelope Convection Dilution Domestic energy consumption Enthalpy Fluid dynamics Gas compressor Heat pump and refrigeration cycle Heat transfer Humidity Infiltration Latent heat Noise control Outgassing Particulates Psychrometrics Sensible heat Stack effect Thermal comfort Thermal destratification Thermal mass Thermodynamics Vapour pressure of water
A vapour seal is an essential part of preventing moisture infiltration into or migration out of a critical space, such as a data processing centre or other room that contains sensitive electronic instrumentation.  Essentially, a vapour seal is a barrier that prevents air, moisture, and contaminants from migrating through tiny cracks or pores in the walls, floor, and ceiling into the critical space.  It is also used extensively on pipe insulation to prevent moisture ingress that may cause deterioration of the insulation or freezing in cold conditions.
A gas that can be retrofitted into a refrigeration system designed for another, without major system changes. For example, R422D is a drop-in replacement for R22 in many applications. However, hydrocarbon refrigerants are NOT drop-in alternatives for most fluorocarbon refrigerants due to substantial system changes needed to manage their differing characteristics (e.g. flammability).

Hi, I'm not sure if this is a question. Are you trying to get a smoother finish when painting with a roller? If so, please be aware that rollers are made with a variety of different kinds of nap. Those with very short nap are designed for smoother walls. Talk with your paint dealer about the surface you're painting and the right roller (and paint) for the job.
Energy efficiency can be improved even more in central heating systems by introducing zoned heating. This allows a more granular application of heat, similar to non-central heating systems. Zones are controlled by multiple thermostats. In water heating systems the thermostats control zone valves, and in forced air systems they control zone dampers inside the vents which selectively block the flow of air. In this case, the control system is very critical to maintaining a proper temperature.
We are open from 7am to 10pm every weekday and from 7am to 8pm on weekends. We book appointments in a 2 hour arrival window and call 30-45 mins before we arrive so you do not have to sit around waiting. It is often possible to schedule your appointment in the evening or morning hours to avoid conflicting with your work schedule. Are you looking for service today? Give us a call or click on one of the Schedule Service buttons found on the top and left sides of this page to contact us today.
Filtration systems -- A second-stage filter is sometimes inserted & used to remove particulates such as pets, smoking or cooking, as well as other odors, gases, and VOCs (volatile organic compounds). A HEPA filter is also available to remove spores, pollens, bacteria and lung-damaging particles. There are also systems that use ultraviolet (UV) light to protect against bacteria and germs.
Headquartered in Portsmouth, Virginia, Air Conditioning Specialists was established in 1997 and is a fully licensed, insured and experienced heating and cooling company. We strive to provide our customers with the quickest, most efficient HVAC service and installation. Our workmanship, along with the highest quality of home and business products available, ensures the dependable performance of your HVAC system and your family’s comfort year after year. Our staff welcomes the opportunity to serve you, and looks forward to building a long-term relationship. Our success is dependent upon 100% customer satisfaction and the referrals we receive from our many satisfied customers.
The chill of winter can be a scary thought when your furnace needs repair. When the furnace in your home goes on the fritz, you need it fixed right away to keep your family safe and comfortable. Every BGE HOME technician is licensed and adheres to a stringent in-house certification program that guarantees their knowledge, affirms their commitment to the customer, and ensures excellence in completing every furnace repair with the highest level of quality.
The main purpose of your furnace filter is to ensure that none of the additional materials your fans pull back into the unit - such as hair and dust - actually damage the furnace or its parts. In the process, it also improves air quality in your home. Some annual inspections will include changing and cleaning this part of the unit. That said, you can also clean or change your furnace filteryourself. Costs for new filters range based on brand, but tend to be around $30.
Central home air conditioner service systems consist of two major components: a condensing unit that sits outside your house, and the evaporator coil (often referred to as an A-coil) that sits in the plenum of your furnace or air handler. The refrigerant in the A-coil picks up the heat from your home and moves it to the outdoor condensing unit. The condensing unit fan blows outside air through the condensing coil to remove the heat. The condensing unit houses the three parts replaceable by a DIYer: the contactor, the start/run capacitor(s) and the condenser fan motor. The condensing unit also houses the compressor, but only a pro can replace that. The A-coil has no parts that can be serviced by a DIYer.
When your furnace filter becomes dirty, dusty and clogged, you can expect some negative effects on your furnace efficiency and your indoor air quality. The forced air is supposed to get blown through the filter and the filter is supposed to trap any particles so they don’t end up in your air ducts and throughout the house. When the filter has trapped too many particles and it is clogged up, the air keeps blowing, but some of those trapped particles will end up in the system and your living space. Another effect is that the furnace has to work harder to get the same amount of air through that dirty filter, so your heating bills may go up.
Need 24-hour emergency furnace repair? We can provide that too. With our same-day service and live phone and online chat service available 24/7, we make your comfort our top priority. Heating and air conditioning should help you live a comfortable life, so let us help you make your home the most comfortable it has ever been. It’s easy, just grab your furnace repair coupon, then simply give us a call at 615-953-9885, chat or schedule an appointment with us online.

Clean the condenser fan blades before the start of the cooling season. Brush any dust or debris off gently and then uncover the condenser coils, gently cleaning the dirty side. Then wrap the motor and other electrical components in plastic bags and gently spray from the inside with a hose. Now check the base pan under the unit and clear it out of any debris that has gathered.


The main purpose of your furnace filter is to ensure that none of the additional materials your fans pull back into the unit - such as hair and dust - actually damage the furnace or its parts. In the process, it also improves air quality in your home. Some annual inspections will include changing and cleaning this part of the unit. That said, you can also clean or change your furnace filteryourself. Costs for new filters range based on brand, but tend to be around $30.

Your comfort is important, and our technicians at Bob’s Heating & Air Conditioning are happy to ensure that that comfort is protected throughout the entire year. That is why we offer comprehensive heating, air conditioning and water heater services in Issaquah, WA. If you need any HVAC or water heater installation, repair or maintenance services, we are the experts you can count on every time.
Air conditioning makes deep plan buildings feasible, for otherwise they would have to be built narrower or with light wells so that inner spaces received sufficient outdoor air via natural ventilation. Air conditioning also allows buildings to be taller, since wind speed increases significantly with altitude making natural ventilation impractical for very tall buildings.[citation needed] Comfort applications are quite different for various building types and may be categorized as:
Combustion gases are generated by the burners in your furnace and passed through a heat exchanger. Air from your home blows across the heat exchanger to be warmed. It is then blown through a system of ducts to distribute around your home. During warm seasons your heating system works with your central air conditioning. Air is cooled as it’s blown over your air conditioning unit’s cooling coil, often attached to the air circulating fan of the furnace, and then sent through the same air ducts throughout your home.
Dehumidification (air drying) in an air conditioning system is provided by the evaporator. Since the evaporator operates at a temperature below the dew point, moisture in the air condenses on the evaporator coil tubes. This moisture is collected at the bottom of the evaporator in a pan and removed by piping to a central drain or onto the ground outside.
The selection of indoor units has one restriction: their total power should not exceed the capacity of the outdoor unit. In practice, however, it is very common to see a multi-split system with a total capacity of indoor units greater than the outdoor capacity by at least 20%. However, it is wrong to expect better performance when all indoor units are turned on at the same time, since the total capacity of the whole system is limited by the capacity of the outdoor unit. Simply put, the outdoor unit will distribute all its power to all operating indoor units in such a way that some of the rooms may not have a very comfortable temperature level. However, the calculation of the total power is not simple, since it takes into account not only the nominal power of the units, but also the cooling capacity, heating, dehumidification, humidification, venting, etc.

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.


Even if your air conditioning unit is still working, depending on the type of system in your home today, you could recoup your investment in a new system in as little as three years. However, that doesn't mean that your system needs to be replaced. Furnaces, air conditioners, and other heating and cooling systems have made tremendous gains in efficiency over the past five years, so if you have an older unit, it is worth taking a look at whether or not a repair is the best investment.
×