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).[4][5][6]
R407C is a zeotropic hydro-fluoro-carbon refrigerant and is a blend of difluoromethane (R32) providing the heat capacity, pentafluoroethane (R125) decreasing flammability and tetrafluoroethane (R134a) to reduce pressure. Difluoromethane serves to, pentafluoroethane andtetrafluoroethane. R407C was developed as a replacement for the ozone depleting R22.
There are multiple reasons to replace your HVAC system. If you have built additions onto your house, you may find your old system no longer meets the requirements for the new dimensions. Perhaps a new technological breakthrough has provided features that will improve your comfort and air quality. Most often, however, you need to replace your system because it no longer works properly.
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.
Hospital operating theatres, in which air is filtered to high levels to reduce infection risk and the humidity controlled to limit patient dehydration. Although temperatures are often in the comfort range, some specialist procedures, such as open heart surgery, require low temperatures (about 18 °C, 64 °F) and others, such as neonatal, relatively high temperatures (about 28 °C, 82 °F).
If your home is not heated using forced air, chances are a boiler will make sure you stay warm during cold nights. A hot water system delivers hot water through a network of pipes that run to every room in your house. The heating effect gets maximized through radiators. The most common issues with hot water heating tend to be not be major, but small problems that add up over time. Mineral deposits within the water tank, a pilot light malfunction, or an issue with a radiator itself can require professional repair. On average, you will pay between $183 and $582 for these problems. The exact amount will depend on the exact problem, as described in our boiler repair cost guide.

How Do You Know When You Need Air Conditioner Repair in Dallas / Fort Worth? Several things can impede the proper function of your air conditioning system. The accumulation of caked on grime and dirt on the condenser coil located outside can force the system to work harder and waste energy. A leak in the coils can result in insufficient refrigerant in the system. Other common culprits for malfunctioning air conditioning systems include a clogged A/C drain and faulty electric controls or sensors. The service professionals at Baker Brothers Plumbing & Air Conditioning will use the latest technology and tools to diagnose your air conditioning system’s problem and correct it quickly and cost-effectively. Our technicians will arrive at your home with fully stocked trucks with the tools and equipment they need to complete almost all jobs within one visit.

This may apply to a system using fresh air for cooling the space or a water cooled or glycol cooled system with an additional coil that provides chilled water cooling when the outdoor ambient is cold; thereby reducing or eliminating compressor operation. These systems may provide free cooling for up to 80% of their operating life, particularly when operating in Northerly climates. See our Free Cooling page for more information.
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.
Cut down on energy costs and prevent damage to your furnace by addressing a gas furnace that's overactive or short cycling. Besides the need for consistently comfortable temperatures, this issue could cause long-term safety issues to your home, making it very important to address. From a faulty thermostat to a dirty filter, there are several possible causes to investigate.

Relative humidity is the ratio of the partial pressure of water vapour in an air-water mixture to the saturated vapour pressure of water at a prescribed temperature. In prevailing Northern European conditions relative humidity and percentage saturation (ration of moisture content) can be considered the same as the divergence is <1%.  In high temperature areas they should be treated differently as the divergence may be as high as 10%.
When central air conditioning service fails during a heat spell, you may have to wait days for an HVAC repair technician or a ac contractor to show up, and you’ll probably pay at least several hundred for the repair. But if you’re comfortable working around electricity and are willing to spend about $50 on parts, you can probably repair your air conditioning service yourself in about two hours and save about $225 on parts markup and labor.

In the UK, the Ozone Regulations[62] came into force in 2000 and banned the use of ozone depleting HCFC refrigerants such as R22 in new systems. The Regulation banned the use of R22 as a "top-up" fluid for maintenance between 2010 (for virgin fluid) and 2015 (for recycled fluid). This means that equipment that uses R22 can still operate, as long as it does not leak. Although R22 is now banned, units that use the refrigerant can still be serviced and maintained.
Our Aurora furnace repair company only employs the highest quality professionals. We realize that dealing with a furnace is very serious, and we only have workers that are highly experienced in doing so. In order to deal with the best company that specializes in furnace replacement in Aurora and furnace repair in Aurora, you have to be sure that the company is professional and committed to a quality customer service experience.
As a Bryant Factory Authorized Dealer, Welzig Heating & Air consistently performs to strenuous standards of technical competence, business ethics, and customer approval.  Our team is NATE-certified, factory trained and regularly updated in progressive technology.  Equipped with leading edge equipment, tools, and a full inventory of genuine manufacturer’s replacement parts, we properly size and install new systems, accurately diagnose existing systems, and resolve the majority of issues right then and there.
When your furnace needs immediate repair, trust the professionals at BGE HOME. We understand that furnace problems are more than a mere inconvenience – they can have a serious impact on the health and safety of you and your family. Our technicians are available 24-hours a day for emergency repairs. Click to schedule your repair and have peace-of-mind knowing that a licensed, certified HVAC technician will have your system up and running as quickly as possible. For 24-hour emergency furnace repair service, call 1-888-243-4663.
Since 1994, Welzig Heating & Air has been providing professional air quality solutions throughout Boulder, Longmont, Louisville, Lafayette, CO & more. We specialize in industry leading products and employ skilled and knowledgeable technicians to do the job right the first time. As a family owned company, we understand how important the quality of your indoor environment can be on your health, comfort, and productivity. When you call the team from Welzig Heating & Air, you’ll enjoy helpful recommendations, convenient appointment times, and rewarding installation service that leaves you feeling refreshed.
Vredevoogd Heating & Cooling Grand Rapids MI routinely serves the areas of Grand Rapids, Wyoming, Lansing, Grandville, and Kalamazoo. We provide a comprehensive menu of HVAC services delivered by certified HVAC technicians who specialize in heating and cooling repair and installation. World-class customer service is a cornerstone of our business and we are committed to doing the job right the first time. We have a reputation for integrity and service excellence. By living up to our good name, we continue to build our customer base throughout the Michigan region and look forward to adding you to our service family. So if you are looking for a “heating & air company near me” in Grand Rapids, or a Furnace Repair Lansing, Furnace Repair Kalamazoo and more. Call today.

When your furnace needs immediate repair, trust the professionals at BGE HOME. We understand that furnace problems are more than a mere inconvenience – they can have a serious impact on the health and safety of you and your family. Our technicians are available 24-hours a day for emergency repairs. Click to schedule your repair and have peace-of-mind knowing that a licensed, certified HVAC technician will have your system up and running as quickly as possible. For 24-hour emergency furnace repair service, call 1-888-243-4663.
Coolray & Mr. Plumber have Smyrna, GA covered when it comes to air conditioning repair and installation, furnace repair and installation, plumbing service and more. We also offer a full range of HVAC and plumbing products to help meet the needs of Smyrna homeowners and businesses. We have been serving Smyrna, GA residents since 1966 and our HVAC technicians and plumbers have the experience and training to properly resolve all of your heating, cooling and plumbing issues. Our products include furnaces, air conditioners, heat pumps, geothermal HVAC systems, traditional water heaters, tankless water heaters, sump pumps, air cleaners & air purifiers and more. 
Packaged terminal air conditioner (PTAC) systems are also known as wall-split air conditioning systems.[36] They are ductless systems. PTACs, which are frequently used in hotels, have two separate units (terminal packages), the evaporative unit on the interior and the condensing unit on the exterior, with an opening passing through the wall and connecting them. This minimizes the interior system footprint and allows each room to be adjusted independently. PTAC systems may be adapted to provide heating in cold weather, either directly by using an electric strip, gas, or other heater, or by reversing the refrigerant flow to heat the interior and draw heat from the exterior air, converting the air conditioner into a heat pump. While room air conditioning provides maximum flexibility, when used to cool many rooms at a time it is generally more expensive than central air conditioning.
When our Denver heating company provides you with maintenance checks before the cold of winter sets in, you will be saving money in several different ways. One of the benefits of a maintenance plan is our technicians will be less likely to have to make repairs throughout the year as long as the system is properly maintained. Our Denver heating company will have your system running at its most efficient, helping to reduce your utility bills each month. An added benefit of a more efficiently running system is the positive environmental effect that it will have.

Cold aisle is a layout design for server racks and other computing equipment in a data centre. Cold aisle data center design involves lining up server racks in alternating rows with cold air intakes facing one way and hot air exhausts facing the other. The rows composed of rack fronts are called cold aisles. See Data Centre Aisle Containment for more information.
Locally owned and family operated, M and M, Heating & Cooling, Plumbing & Electrical customizes solutions to perfectly fit your requirements and lifestyle. We specialize in a wide range of services including plumbing, water heating, indoor air quality, and residential and commercial temperature control. Our team of highly trained and certified technicians are fully licensed and insured, adhere to strict service procedures, and meet exacting standards of quality. Call on M and M, Heating & Cooling, Plumbing & Electrical at (720) 443-6119 for dedicated service throughout Longmont, CO & surrounding areas, and have confidence in a rewarding experience and long-term results. With over eighteen years of satisfied customers, we take great pride in a job done right.

Air Conditioning Your home's air conditioner is an essential part of your overall indoor comfort. A properly working system can mean the difference between a cool, comfortable summer and a hot, miserable few months. If you're currently dealing with a broken air conditioner, an inefficient system, or you would like to schedule a routine, pre-season tune-up, Horizon Services is here to help!
Roof-mounted systems have the heating and cooling systems in one cabinet. Sometimes called "gas packs" (if the heater uses natural gas), they typically cost less than a comparable split system. In dry regions, most homes originally had "swamp-coolers" installed. When replacing them with HVAC systems, it's often cheaper to use existing mounts and ducting.
This job involves removing the access panel, loosening a couple of bolts that hold the blower motor at the proper tension, and adjusting its distance or realigning the belt. In many cases, it’s a good idea to remove the belt and buy a replacement at a home center. Last, when reinstalling the belt, be careful not to over-tighten it; this can wear out the motor bearings.
BGE HOME HVAC repair technicians are thoroughly trained and certified to work on all major brands of heating and air conditioning equipment. When your system breaks down and needs a heating and air conditioning repair, you want to call someone you can trust. Need air conditioning service in the middle of the night? Emergency heating and cooling HVAC service is available 24 hours a day by calling 888-243-4663.

"The estimator and install crew from TN Bowes get 5 stars from me. Everyone was friendly and professional, and the attention to detail was evident throughout the job. The crew stayed onsite until they were sure that the system was functioning, and everything was cleaned up well. I will continue to refer friends and family to TN Bowes for all their HVAC needs!"
The re-processing and upgrading of refrigerant by filtering, drying, distillation and sometimes chemical treatment of the recovered refrigerant. The re-processed substance will require laboratory analysis to verify that it meets a specific quality standard, normally that of new refrigerant. This normally involves processing “off-site” at a re-processing or a refrigerant manufacturing facility.
Bonney’s NATE certified technicians will troubleshoot and repair your furnace for safe and reliable operation. Our technicians use state of the art tools including video inspection cameras and exhaust gas analyzers to perform thorough, comprehensive diagnostics when equipment is broken. Furthermore, we arrive in a “warehouse on wheels” stocked with many parts to get your furnace repaired as quickly as possible.  For an unexpected heater repair Bonney offers financing to make your comfort affordable.
If you buy a great heating system but do not schedule an outstanding heating installation in Issaquah, WA, then you are throwing your money out the window, right along with your comfort. No matter how great your heating system may be, there is no way it will live up to its full potential if you do not have it professionally installed by a skilled Issaquah, WA heating installation technician.
Dunes Heating And Air Conditioning is HVAC Contractor providing the best possible Heating and Air Conditioning Repair, maintenance and installation for your home or business in Mount Pleasant, Charleston and Isle of Palms South Carolina. You can count on us to provide you with a system and solution that fits your unique needs and since we've installed many systems in this area, we've earned a reputation for doing the job right the first time.
The thermocouple is a copper rod that the pilot flame heats-up. When it gets hot enough, the thermocouple signals that there is enough heat to burn the gas fuel being released into the appliance—and so it allows the gas to be released to the burners. In some cases where the pilot light won’t stay lit, the thermocouple needs to be adjusted or replaced. This is generally a job for a professional.
Fresh-Aire UV is an innovation leader in the field of indoor air quality. Our award-winning UV light and carbon products fight mold, bacteria, viruses and odors in commercial and residential HVACR systems. Our products include Blue-Tube UV®, the world’s most popular germicidal UV light, the revolutionary APCO® PCO/carbon whole-house air purifier, and Mini UV the first UV light system designed specifically for mini-split AC systems.
A more efficient method of controlling humidity is to use the waste heat from the refrigeration cycle itself. Instead of rejecting the waste heat outdoors, the heat is directed inside when humidity control is required. One form of heat reclaim is called hot-gas reheat or “refrigerant desuperheating” where refrigerant is passed through a heat exchanger located downstream of the cooling coil. The hot high pressure vapor leaving the compressor passes through this heat exchanger prior to entering the condenser coil. This in turn heats the indoor air and again causes the AC system to run longer to meet the thermostat set point. Although more energy is used, this is much more efficient than turning on an electric heater. Another form of heat reclaim is called sub-cool reheat. This strategy takes the warm liquid refrigerant from the condenser and passes it through a heat exchanger located downstream of the cooling coil. Less heat is available using this method because the majority of the heat has already been rejected at the condenser. Since more energy is used to pump liquid (as opposed to a gas) through the heat exchanger it would appear that this method is less efficient than the hot-gas method, however, the liquid in the heat exchanger is sub-cooled in the cold supply air stream which increases the capacity of the air conditioner. Since more capacity is available, the AC units is able to meet the thermostat more quickly.
There are a number of claims in the HVAC industry that make HVAC technicians sound like they know what they are doing, but the North American Technician Excellence (NATE) certification program is the only closed book examination and certification program, administered by a third party, that tests real world working knowledge of HVAC systems. That's why all of our service technicians complete and continue NATE certification training throughout their career with SMO.

SEER is related to the coefficient of performance (COP) commonly used in thermodynamics and also to the Energy Efficiency Ratio (EER). The EER is the efficiency rating for the equipment at a particular pair of external and internal temperatures, while SEER is calculated over a whole range of external temperatures (i.e., the temperature distribution for the geographical location of the SEER test). SEER is unusual in that it is composed of an Imperial unit divided by an SI unit. The COP is a ratio with the same metric units of energy (joules) in both the numerator and denominator. They cancel out, leaving a dimensionless quantity. Formulas for the approximate conversion between SEER and EER or COP are available.[34]


If you are using existing ducting, it will have to be inspected. Proper ducting loses around 2% to 5% of your energy. Old, leaking ducts can lose 50% or more. A contractor will need to have the ducts inspected and replace any parts ahead of time. If you are changing the size of your HVAC system because of significant changes to your home, you might need to replace the ductwork regardless.


Vredevoogd Heating & Cooling Grand Rapids employs more than 80 people who are proud to work under the Vredevoogd Heating & Cooling banner. Each team member shares our company values for service excellence. All of our employees are intensely screened and background checked so that you have peace of mind when they enter your home. Moreover, our technicians are certified to work in the HVAC industry and provide the level of expertise that our customers expect from Vredevoogd Heating & Cooling. We back our technicians’ work and continue to make training a priority so that all of our techs are familiar with the latest HVAC models and advances. Our customers deserve the best, so the best is what we deliver to each and every job.

This type of furnace is fueled by liquid propane gas, which is burned to push hot air through your home. A pilot light ignites the burners within a combustion chamber, which push heat into the heat exchanger and eventually through your entire home. Repairing this type of furnace can be more expensive than its electric alternative. For example here are some common propane gas repairs and their costs:


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.

A heat pump is an air conditioner in which the refrigeration cycle can be reversed, producing heating instead of cooling in the indoor environment. They are also commonly referred to as a "reverse cycle air conditioner". The heat pump is significantly more energy efficient than electric resistance heating. Some homeowners elect to have a heat pump system installed as a feature of a central air conditioner. When the heat pump is in heating mode, the indoor evaporator coil switches roles and becomes the condenser coil, producing heat. The outdoor condenser unit also switches roles to serve as the evaporator, and discharges cold air (colder than the ambient outdoor air).
Owning a home comes with so much responsibility. Finding the right professionals to help ease the burden of keeping up with the vital systems in your residence is important. When it comes to keeping your heating and cooling unit in good working order, you need to call on Deljo Heating & Cooling for help. We have been in the HVAC repair business for many years and will have no problem extending a helping hand when you need it. Hiring us will allow you to take advantage of a number of benefits.
Whether it's heat repair issue, a heat pump issue or furnace problem you're facing, we provide our Leesburg and Ashburn residents and businesses full heat pump and furnace service repairs in a professional and prompt manner. We pride ourselves on employing only premier technicians to provide you with home and central heating repair service. Operators are standing by to take your call.
Our Aurora furnace repair company only employs the highest quality professionals. We realize that dealing with a furnace is very serious, and we only have workers that are highly experienced in doing so. In order to deal with the best company that specializes in furnace replacement in Aurora and furnace repair in Aurora, you have to be sure that the company is professional and committed to a quality customer service experience.
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

In the event of an emergency with your residential heating and cooling system, we understand that you simply cannot wait! At R.S. Andrews, we take your comfort and well-being seriously and are proud to offer our emergency HVAC repair at any hour, on any day—including weekends! We provide only the highest quality services to ensure your needs are met!
Within the construction sector, it is the job of the building services engineer to design and oversee the installation and maintenance of the essential services such as gas, electricity, water, heating and lighting, as well as many others. These all help to make buildings comfortable and healthy places to live and work in. Building Services is part of a sector that has over 51,000 businesses and employs represents 2%-3% of the GDP.
Keep in mind that ducts used for heating might not be the right size or in the right location for optimal cooling. Your contractor should ensure that duct sections are properly sized and that there are enough supply registers to deliver sufficient air to the right spots. Undersized ductwork can make for inefficient and noisy operation. Here’s how to keep yours humming:

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 main problem when installing a multi-split system is the laying of long refrigerant lines for connecting the external unit to the internal ones. While installing a separate split system, workers try to locate both units opposite to each other, where the length of the line is minimal. Installing a multi-split system creates more difficulties, since some of indoor units can be located far from the outside. The first models of multi-split systems had one common control system that did not allow you to set the air conditioning individually for each room. However, now the market has a wide selection of multi-split systems, in which the functional characteristics of indoor units operate separately from each other.
Who do you call when you have a HVAC related issue? How do you know that you’re making a call to the right team? Much of Cary has come to trust us here at Service Experts Heating & Air Conditioning for all their heating and air conditioning needs. Our qualified technicians know what they’re doing. No matter your problem or question, our team is able to help—no issue is too big or too small in Cary. You can feel comfortable in your decision to call Service Experts and know that you’re working with a team that has your back.
Finally, don't underestimate the thermostat as a potential reason why your furnace is not working. Everything on the heating unit itself may function perfectly, but your home still will not heat right if the console you use to set the temperature doesn't communicate your input. A faulty thermostat can either be due to the wall unit itself, or the wiring that connects it to your furnace. Average thermostat repair costs are between $108 and $282, including labor. Replacement costs, of course, depend on the thermostat you choose. Visit our thermostat repair cost guide to learn more about this type of issue.
Window unit air conditioners are installed in an open window. The interior air is cooled as a fan blows it over the evaporator. On the exterior the heat drawn from the interior is dissipated into the environment as a second fan blows outside air over the condenser. A large house or building may have several such units, allowing each room to be cooled separately.
You can count on The Goodman GSX140241 Air You can count on The Goodman GSX140241 Air Conditioner Condenser to keep you cool on even the hottest summer days. The high efficiency compressor operates in tandem with a high-efficiency coil cooling your home effectively. The Goodman ARUF31B14 Air Conditioner Air Handler features a check flowrater expansion device. The Goodman ...  More + Product Details Close
Designed to improve manufacturing process control in a printing plant, Carrier's invention controlled not only temperature but also humidity. Carrier used his knowledge of the heating of objects with steam and reversed the process. Instead of sending air through hot coils, he sent it through cold coils (filled with cold water). The air was cooled, and thereby the amount of moisture in the air could be controlled, which in turn made the humidity in the room controllable. The controlled temperature and humidity helped maintain consistent paper dimensions and ink alignment. Later, Carrier's technology was applied to increase productivity in the workplace, and The Carrier Air Conditioning Company of America was formed to meet rising demand. Over time, air conditioning came to be used to improve comfort in homes and automobiles as well. Residential sales expanded dramatically in the 1950s.[citation needed]

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.

Air conditioner equipment power in the U.S. is often described in terms of "tons of refrigeration", with each approximately equal to the cooling power of one short ton (2000 pounds or 907 kilograms) of ice melting in a 24-hour period. The value is defined as 12,000 BTU per hour, or 3517 watts.[32] Residential central air systems are usually from 1 to 5 tons (3.5 to 18 kW) in capacity.

The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. In ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.[5]
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.
The heat-exchanger cools the air that is being forced through it by the furnace blower. As the warm air comes in contact with this cool surface the water in the air condenses. By pulling the water molecules from the air. According to the psychometric chart[42] as relative humidity decreases in order to feel cool you will have to lower the temperature even more. A common way to counteract this effect is by installing a whole-home humidifier.[43] Similarly, installing a high efficient system this need to turn the temperature down wont have such and influence on your energy costs.
Start with your utility company; they can help a great deal. Comparing previous bills isn't always a good measure, as the weather is never exactly the same month to month. Instead, if you take your energy bill and divide it by the square footage of livable space in your home, don't count areas like unfinished garages or basements -- you can calculate how much you are spending to heat or cool each square foot of your home. Your energy provider can tell you what the average cost per square foot is in your region for that same period of time so you can compare apples to apples.
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