Cats and Air Conditioning
Nest Thermostat Review
Video Review and Brief Overview of Installation
How To MaKe Your Own Air Conditioner
Home Made A/C- How To Video
Economy Effects HVAC Buying Habits
Economy Issues Affect Change in Consumer Shopping Habits
By Betty Stephens
American household buying habits accounts for around 70% of the U.S. economy. What consumers shop for is seperated into two main categories. First, they spending on such items as food, clothing and shelter. Second, there is more discretionary spending. This is on items such as entertainment or non-essentials.
The good fortune of some and mis-fortune of others have caused financial ups and downs and a shift in the shopping habits of Americans have led to uneven outcomes for retailers. Companies like WalMart and Mattel have continued to struggle as people spend more cautiously in this type of uncertain economy. Amazon has however done well, as more consumers choose to shop on line.
Americans are very price conconscious, and will check as many as seven store or web sites for the best price before makes their purchases. I believe frugal is the the best word to describe the average American these days. Internet shopping rose 10% to $46.5 billion in November and December, according to research firm Comscore. However, sales at retail stores rose just 2.7% to $265.9 billion, according to ShopperTrak, which tracks data at 40,000 stores in the U.S. And the number of customers in stores dropped 14.6%.
Industry exucutives are starting to say this new American frugallity may be beccoming a new reality and a new permanet way of life in America and they don’t expect to see it go away anytime soon, if ever, even as the economy shows signs of improvement. With family budgets under pressure since the recession of 2008, consumers have headed to discount stores, switched from name brand goods to private-label alternatives and shopped more often at discount stores or online rather than spending on expensive fuel to drive to out-of-town hypermarkets.
Those trends have benefited discounters as well as retailers that have the widest own-label ranges and networks of smaller stores, prompting consumer goods firms to retaliate with brand promotions and smaller packaging.
“If you look at data from Millennials, who have really sort of grown up with this, price is more important to them than it was to the last generation,” WalMart U.S. Chief Executive Bill Simon told the Reuters Global Consumer and Retail Summit, referring to the generation born between 1980 and 2000.
WalMart U.S. is the largest unit of WalMart Stores Inc (WMT.N), the world’s largest retailer which benefited from trading-down during the recession, but cut its forecasts last month, citing weak results in many key markets.
The U.S. economy is expected to pick up towards the end of the year, helping cut unemployment, while Europe’s lack luster recovery looks set to continue, although wage growth will continue to lag inflation, hurting consumer purchasing power.
The Dollar Channel
Dollar store has been on an upward trend for several years now. They have had a big impact on the discount store market and are competing head to head with other discount stores on the routine shopping trip stop. The Family Dollar Stores are adding cooler space to more than 1,000 locations this year, and Dollar Tree is adding to its food and beverage assortment as well as opening a third-party pharmacy in a Florida location. Efforts like these have contributed to dollar retailers winning over shoppers from other discount stors. The most sizeable change is the shift of heavy drug store shoppers—the top one-third of spenders within the catagory -into the dollar store family of stores. This is not a big surprise, as the both dollar stores and drug stores carry many of the same type of goods and both are well positioned, geographically, for easy-access, fill-in trips.
Changing Habits
During the last year, Americans have been making less but larger shopping trips. Trips declined across grocery and large box stores. You might think the decline in stock-up trips would hurt Sam’s Club and Costco type stores, however trips have actually increased by 2.1% during the past year due to a number of factors. The club retailers are expanding the number of stores. Also, club trips are being bolstered by lower gas prices and low food inflation, which makes it easier for them to absorb bulk pricing. The dollar stores also saw trips increase significantly during the past year, which reinforces the notion that consumers are viewing dollar stores as a “smarter” choice for affordable solutions.
While people will continue to shop, the question now is what will they purchase, when will they purchase and where will they purchase. Name brand items are taking a backseat to generic or store brand products. Malls are beginning to show signs of weakness – a lot more stores are closing while consumers make their way to other, more affordable alternatives. Instead of going to one of the mall’s “anchor stores,” they are now going to places like WalMart, Target or K-Mart to purchase the things their families “need” rather than the things their families “want.”
graphics from Google Images
HVAC Future Trends
Future Trends for HVAC Industry
By Betty Stephens
HVAC technology is constantly changing due to new discoveries and influences outside the industry. As recently as this century, central, indoor climate control was available to only a privileged few. Today, even central air-conditioning in homes is common in the U.S. Improvements occurred through a number of factors such as technical, market changes, energy and environmental concerns, and political decisions. Changes continue to occur and they benefit of our customers and are our part of our future.
Environment:
The environment has possibly had more influence on HVAC technology than has energy. The environment will continue to impact the industry into the foreseeable future.
Policies regarding climate change have also directly impacted our industry. As we design and operate more energy-efficient equipment and systems, we use less energy, energy that, in many cases, comes from burning CO2-producing fossil fuels.
The environment will continue to impact the industry. The industry has proven that it can respond in a timely way. As new environmentally friendly products are developed, those products are also more energy efficient. Adopting new technologies and supporting research will help our industry meet the challenges of the future.
User-Friendly Controls
While smart, Wi-Fi-connected thermostats promise significantly increased energy efficiency, the real draw for homeowners seems to be how easy the interfaces are to operate. Take the Nest Learning thermostat, for example. It is programmed by the user to remember his preferred temperature settings. If the user prefers the thermostat to kick in a faster, warmer temperature, on cold, wintery mornings, the Nest thermostat will store that information and adjust the temperature accordingly. The thermostat also monitors temperature with humidity and activity sensors, and it can determine regional climate by the user punching in their zip code
Wireless-controlled thermostats present HVAC data in a language that contemporary consumers understand. Homeowners are accustomed to easily digestible, visual representations of information and data. The reporting tools that smart systems include take the mystery and obscurity out of an industry that has been thriving on overall complacency from its customers.
DEVap Air Conditioning
The National Renewable Energy Laboratory (NREL) developed the DEVap (desiccant-enhanced evaporative air conditioner) in 2011 and estimates that it reduces air conditioning energy usage by 40-90 percent. So far, DEVap is found primarily in commercial buildings, and the technology is so new that it’s difficult to find for residential use. But, given how promising the innovation seems, and how cost-effective it has already proven to be, and is anticipated great gains in the future.
Zero Energy Buildings
Zero-energy buildings that produce energy instead of just using large quantities will gain traction with companies that target eco-friendly employees and consumers. Many businesses are already headed in this direction with geothermal heating and cooling, solar-powered systems, and white roofing. If HVAC manufacturers can work to design structures that are both energy efficient and comfortable for their residents, we’re sure to see some fresh companies take on the challenge.
Variable Refrigerant Flow Systems
A popular trend in Eastern markets, variable refrigerant flow (VRF) is the future of the HVAC industry. Though US market have yet to reach the demand experienced abroad, VRF systems are establishing their place as in-demand items for housing and commercial cooling needs. Simple and elegant in design, VRF systems connect an outside condensing unit to several fan coil units throughout the building. Each coil and evaporator in the system can be controlled individually to reduce waste from over-allocated resources. The shift will stimulate job growth and overall economic development throughout the HVAC sector that will continue well into the coming years.
Career Trends
Current industry trends indicate a future growth rate of nearly 28% nationwide. This trend is predicted to continue until 2018, a total period of researching and studying 10-year industry trends beginning in 2008. Studies have revealed that once the results of that research and those studies are complete, there will be nearly 395,000 individuals who make their living in the HVAC industry, and choose to make this their lifelong career Choice. The rate of change in our industry will be exponential. Some changes will be caused by improvements in technology whereas others will be the result of influences outside our immediate control. As engineers, we have an obligation to be proactive in encouraging changes that are of benefit to the society we serve. This in turn will have direct benefit to our industry and to each of us individually.
In Summary
Building Management Systems and air-conditioning controls systems will develop to become:
• Intelligent self-learning systems that measure the performance characteristics for the building and its systems for different ambient and occupancy conditions and using thermal modelling technology are able to operate the buildings systems to provide the require conditions whilst minimizing energy consumption and plant wear and tear.
• Self-checking systems that are able to eliminate the fly by wire problems that many systems suffer from, which the head end computer is thinking one thing is happening however in the field the actuality is very different.
• Self-diagnosing systems that are able to determine fault conditions analyses the cause and report or even rectify the condition, systems that are able to recognize fault situations that are resulting in excess energy consumption or unacceptable equipment wear and report.
• Systems with seamless remote access, diagnosis and control functionality.
• Systems with the flexibility to take advantage of wireless technology and the onboard intelligence that is already starting to be installed in items of central plant
Phase-out of 134a for cars
Phase-out of R134A Refrigerant for Cars
By Betty Stephens
Environmental Protection Agency
The Environmental Protection Agency has issued a pair of decisions that begin a changeover of the refrigerants that do the cooling in car air conditioners. Over the next few years, it will be out with the old (HFC-134a) and in with the new (HFO-1234yf). Cars will be cooled with less global warming.
Both chemicals are hydro fluorocarbons, but the 134a in a car today is a “super greenhouse gas” with 1,430 times the global warming kick, pound for pound, of carbon dioxide. The new refrigerant, 1234yf, has just 4 times the global warming potency of CO2 and cuts the climate damage from car air conditioning by more than 300-fold. Changing over to 1234yf is a big step forward, because car air conditioning is one of the biggest, leakiest, and fastest growing uses of HFCs worldwide. And if HFC growth is left unchecked, these chemicals are responsible for a major share of future climate change.
1234yf Alternative
The other new alternative to R134A is HFO-1234YF, which has similar properties to R134A but meets the new European global warming standards. Refrigerant HFO-1234YF has a global warming potential rating as well as an ozone depletion rating, and as of yet, the HCO-1234YF is the only refrigerant that meets both EPA and European standards. HFO-1234YF is also a Class 2 flammable gas although slightly less flammable than the R152A.
Other Class 2 refrigerants found on the market, but not recommended for automotive use include R1143A, R142B and R143A. In February, after a long review, EPA approved 1234yf as an acceptable alternative for use in new cars. That action was supported by DuPont and Honeywell (who are ready to make the chemical), by most domestic and import automakers, and by NRDC. Two other compounds have also been approved, but car makers appear to favor 1234yf because it requires the smallest design changes to the air conditioning equipment.
Reaction among the car makers appears mostly positive. General Motors started using 1234yf in some 2013 models. Many other car companies are quietly making arrangements with chemical suppliers.
Car makers actually have incentives to act quickly, because switching refrigerants earns them significant credit towards meeting the global warming standards set under the Obama administration’s landmark Clean Car Peace Treaty. Those standards, applicable to 2012-2016 model cars, cover four greenhouse gases – CO2, methane, nitrous oxide, and HFCs. Switching from 134a to 1234yf yields twice as much credit towards the “CO2-equivalent grams per mile” standard as merely cutting leakage of 134a.
Replacement Windows
Replacement Windows-Air Infiltration
By Betty Stephens
Air infiltration refers to air leakage through unsealed joints in a structure and around the windows. The Air Leakage (AL) rating pertains to leakage through the window assembly itself. Air infiltration can also occur around the frame of the window due to poor installation or poor maintenance of existing window systems. Make sure windows are properly installed and maintained (caulking and weather-stripping). Cold glass can create uncomfortable drafts as air next to the window is cooled and drops to the floor. This is not a result of air leaking through or around the window assembly but from a convective loop created when next to a window is cooled and drops to the floor. This air movement can be avoided by installing high-performance windows.
Heat loss and gain occur by infiltration through cracks in the window assembly. It is indicated by an air leakage rating (AL) expressed as the equivalent cubic feet of air passing through a square foot of window area. The lower the AL, the less air will pass through cracks in the window assembly. At this time, the AL is optional among NFRC ratings. For code compliance purposes, however, air infiltration is often tested in accordance with the North American Fenestration Standard (NAFS), which produces similar results to the NFRC air leakage rating. Select windows with an AL of 0.30 or less (units are cfm/sq ft)
The American Architectural Manufacturers Association (AAMA) reports that any residential window that achieves a rating below 0.30 cfm/Sq.Ft meets the requirements for their gold rating. This is the best rating they offer. This is also the minimum air infiltration rating for the energy star program. This minimum rating may be reduced with the 2015 energy star program.
How do you know if there is Leakage?
The two recommended options in determining if a window, door or skylight will allow in too much air:
• Look for an AAMA certification label on the window to determine that the product has been designed to meet air infiltration standards.
• Determine if the product has been tested and authorized for AAMA certification by researching the product in the AAMA Certified Products Directory. Contact the manufacturer of your specific product to request test data.
Note: Certification programs offer enhanced quality that is not built into the basic testing process. Certification quality control measures include two unannounced manufacturer plant inspections by a third-party validator.
Replacing Windows
There are many factors to consider when choosing a replacement window, including visual appeal, style of operation, affordability, and last but not least is performance.
1. Structural Integrity
Structural integrity is the ability of a structure or a component to withstand a designed service load, resisting structural failure due to fracture, deformation, or fatigue… Structural integrity is the quality of an item to hold together under a load, including its own weight, resisting breakage or bending. It assures that the construction will perform its designed function, during reasonable use, for as long as the designed life of the structure. Items are constructed with structural integrity to ensure that catastrophic failure does not occur, which can result in injuries, severe damage, death, or monetary losses.
2. Thermal Performance
Thermal performance of a building refers primarily to how well a building is insulated from the external weather conditions in order to achieve a comfortable temperature internally. This means keeping the internal temperature higher than the external temperature or lower than the external temperature (not a common occurrence in Ireland). The comfortable range of room temperature is 19-22 degrees C.
There are a number of factors that determine the thermal performance of a building. The best known factor is the insulation value of the materials used in the fabric of the building (i.e. floors, walls, roof). This value is known to most of us as the U-Value of the material. The lower the U-Value the better. If the U-Value of a material reached 0 it would prevent any energy (heat) from being lost.
Other Factors
Other factors that influence the thermal performance of a building are air-tightness, cold-bridging, junction details and how the materials are brought together or fitted on site. If a high performing material is poorly fitted its effectiveness can be dramatically reduced. One result of poorly installed insulation is “thermal looping”. A thermal loop is a movement of air driven by warm air rising at one end of the loop, and cool air descending at the other end, creating a constantly moving loop of air.
U- Values are a true reflection of the thermal performance, only when the insulation is fitted correctly. No matter how thick the insulation is or how good the material is, if it isn’t fitted correctly and an air gap is formed then the performance of the structure is drastically affected. Heat flows from a high temperature point to a cold temperature point, and will find the path of least resistance. In a traditional masonry structure where an air gap occurs between the insulation and the cold masonry/block surface, air can circulate from the warm side of the insulation to the cold side. The heat is pouring out at this point.
The Best Windows from Consumer Reports’ Tests
New windows can make your home quieter, more attractive, and less drafty, and they don’t need painting. But replacing your windows is expensive, and there are lots of decisions to make before you swipe your credit card. Here’s what you need to know plus some window picks from the experts at Consumer Report:
The best windows from tests
In our tests of wooden, vinyl and fiberglass double-hung and casement windows we found 12 that performed well enough to recommend including four that we named CR Best Buys. Here is the top model of each type we tested.
• Wood double-hung: Andersen 400 Series, $310 per window
• Vinyl double-hung: Simonton Pro-Finish Contractor, $260
• Fiberglass double-hung: Integrity from Marvin Ultrex, $450
• Wood casement: Andersen 400 Series, $400
• Vinyl casement: American Craftsman by Andersen 70 Series, $260, sold at Home Depot
For more choices see our full window Ratings and recommendations and read our recent reports, “How to choose replacement windows” and “When to repair and when to replace your windows.
Do It YourSelf WebSites
Online Sites for HVAC Do-It-Yourselfers
A Review
By Betty Stephens
Need help in getting started on a Do-It-Yourself HVAC project? Here are some links to resources that may help you out.
Ductworks: The Original On-Line DIY Heating & Cooling – A Help site for Do-It-Yourself homeowners and builders to set them save money by offering initial help when they cannot find what they are looking for. May call or fill out a “Contact Us” form and they will find it for you. They are providers of HVAC products
https://www.ductworks.net/
Mold in HVAC System – Mold Removal Guide | Air Conditioner
removemoldguide.com/do-it-yourself/remove-mold-in-air-conditioning.
You are guided through the steps for your DIY air conditioner mold removal project.
www.central-air-conditioner-and-refrigeration.com/central_air_condition
o
HVAC Parts: If you’re not, changing the filter once a month, it will help. You’ll be … You may read this “Fix It Yourself or Do It Yourself” material online and it sounds great. You try it … You won’t find any professional hvac site that will teach how to installs it.
http://http://www.hvacpartsoutlet.com/
Need assistance finding your furnace or air conditioner parts? This site caters to do it yourself (DIY) homeowners and handymen, as well as HVAC Help Desk. McAfee SECURE sites help keep you safe from identity theft, credit card fraud..
www.doityourself.com/
Website and internet advice for HVAC businesses: Office manager or unlucky ones that been told to “get us on the internet” or “fix than website! A couple of great do-it-yourself website software), goal is to cut through the noise and demystify the online marketplace, and to help you achieve a better understanding.
www.energystar.gov
HVAC Maintenance Tips • For Home Improvement Homeowners choose to take on duct sealing as a do-it-yourself project. Do-It-Yourself Air Conditioning Repair – YouTube
www.youtube.com/watch?v=KCGpX2ru2Xc
Denver, CO Plumbing & HVAC Parts Department:
http://www.bellplumbing.com/denver-remodeling/plumbing-parts-departme
Do it yourself plumbing and HVAC projects in the Denver area: If an exact replacement is no longer available, we’ll help you find the best HVAC Training Videos, Watch and learn how to do hvac.
www.hvac-for-beginners.com/hvac-training-videos.html
Do It Yourself Geothermal Installations:
www.geothermalgenius.org/…/diy-geo-do-it-yourself-geothermal-installa
Web site for HVAC Repair Beginners. If you are having problems with your heating or cooling system, you should be able to find most of the common problems by using the air conditioner, furnace, heat pump, or boiler troubleshooting.
http://www.hvac-for-beginners.com/
Do-it-Yourself Heating, Air Conditioning, and Ventilation: Contact for all of your do-it-yourself heating, air-conditioning, and ventilating needs.
http://dalehuberco.com/
HVAC Installation: Doing a home HVAC installation is rather straight forward. Do it yourself what you may think will be the easiest part of a home HVAC installation is probably is not.
www.doityourself.com/stry/hvac-installation
Ductwork Design Services and heating & cooling products for the Do-It-Yourself homeowner. The design services start at $275 and include a Free Step-by-Step Ductwork Installation DVD with each design package. Half of your design fees can be applied to the purchase of your complete HVAC system.
https://www.ductworks.net/
RV A/C
Natural Gas Versus Propane A/C Cooling Units for RV’s
By Betty Stephens
If you drive an RV in the summer you know the heat can be a problem. The built in HVAC for the cab does not seem to be strong enough to cool the entire RV, so when you’re driving in extreme heat it may be necessary to run the generator to power the living area A/C to cool down the RV. There may be times in the summer that is may be necessary to have two A/C units running to cool RV (cab and living area AC).
To rapidly cool the living area on hot days try closing all the vents in the bedroom, opening the vents on the front A/C along with all the vents in the living area, shut the door to the back area of the RV and turn up both A/C units. Having the rear vents closed forces most of the cold air into the front part of the RV and helps cool it down.
Recreational vehicles normally have an air conditioner vents located on the rooftop. The location of the air conditioner means excellent cooling power and it can work well even when you are driving on the highway. Air conditioners in RV’s work like a typical refrigerator does. It does not cool the room down, instead it removes the heat. It takes the heat from the RV and dispose of it outside.
Parts of the Air Conditioner
An air conditioner has eight main parts: a compressor, condenser, evaporator, wires that
connect the parts together, an air moving system, a fan to push the air over the
condenser and another fan to push air over the evaporator. It also contains liquid for
cooling.
The RV’s AC compressor performs the job of circulating the Freon through the condenser and evaporator coils cooling fins and the cycle is repeated as the thermostat setting determines it necessary. Both the compressor and the fan motor use capacitors to provide a high voltage charge to get them moving and a lesser charge to keep them running. Only one capacitor is usually used for both fan and compressor. It the capacitor goes bad, neither the fan nor the compressor will start.
Energy Source
The air conditioner runs on what is known as AC power. The AC power is derived from a 120 volt socket that is plugged into a generator or a home. A gas generator burns a gallon of gas every hour and may be costly. It is a wise idea to use another power source such as a home or a generator that does not use gasoline.
The Compressor
Compressors condense the refrigerant vapors and heat it up as it condenses it. Then it moves to the condenser where the heat is taken out by the fan. This makes the vapor cool and becomes a liquid. The liquid slides down the capillary tubes and on to the evaporator. The liquid begins to soak up the heat from the air in the RV as it moves along it by the evaporators fan. This makes the liquid expand and when the liquid has soaked up enough of the RV’s heat, it becomes a vapor once again. This overly heated vapor is sucked by the suction the compressor creates and the cycle repeats itself.
Propane Cooling Unit
Propane is a liquefied petroleum gas, used in RVs for heating, cooking and refrigeration. It may be called bottle gas, referring to how it is sold and stored. Propane offers the RV owner these advantages:
1. Liquid propane is more readily available than gas in a power outage as gas stations may also lose power causing the pumps from working.
2. Liquid propane can be stored indefinitely whereas gasoline tends to go off after a few months.
3. Liquid propane is a clean burning fuel and the propane generator produces less emissions than a gasoline or diesel powered generator.
(LP Gas – Propane; abbreviation for liquefied petroleum gas, which is a gas liquefied by compression, consisting of flammable hydrocarbons and obtained as a by-product from the refining of petroleum or natural gas. It is also called bottled gas, LPG (liquid petroleum gas) and CPG (compressed petroleum gas).
Natural Gas Cooling Unit
A gas cooling unit uses ammonia as the coolant, and water, ammonia and hydrogen gas to create a continuous cycle for the ammonia.
It works like this:
Heat is applied to the ammonia and water solution in the generator. As the mixture reaches the boiling point of ammonia, it flows into the separator. Ammonia gas flows upward into the condenser, dissipates heat and converts back to a liquid. The liquid ammonia makes its way to the evaporator where it mixes with hydrogen gas and evaporates, producing cold temperatures. The ammonia and hydrogen gases flow to the absorber where the water collected in the separator in step No. 2 mixes with the ammonia and hydrogen gases. The ammonia forms a solution with the water and releases the hydrogen gas, which flows back to the evaporator. The ammonia and water solution flows toward the generator to repeat the cycle.
Ceiling Fans
DO CEILING FANS HELP LOWER ELECTRIC AND A/C BILLS?
By Betty Stephens
Ceiling fans can cut back excessive use of your home’s air conditioning and heating unit and use 5% less energy. They use about the same energy as a 100-watt light bulb.
The Department of Energy says YES. The Department of Energy’s Energy Information Administration predicts that the price for natural gas, used for electricity and heating fuels, may increase 65 percent this winter .So, it is time to start thinking about ways to save on heating and cooling, especially since it makes up 45 percent of an energy costs. The answer to saving money is with a ceiling fan.
Turn on Fans
Fans make a room feel cooler, and the one in our living room quit w Turn up your thermostat because a ceiling fan can make an air-conditioned room feel four degrees cooler.
Savings with a Fan
The ceiling fan works to move the air throughout the room, which makes cooler. If you use a ceiling fan in cooler climates, it can actually make a house feel cool enough to prevent the need for an air conditioning. In hotter climates, a ceiling fan can make an air-conditioned room feel four degrees cooler, allowing you to raise the thermostat. By raising it two degrees, you can save up to 14 percent on your yearly energy bill.
Always turn off the fan when no one is in the room. Ceiling fans make people feel cooler, but they won’t actually change the temperature of a room like an air conditioning unit would. So there’s no point in burning the energy used by a fan when the room is empty.
Using the Fan
A ceiling fan should rotate counter-clockwise (in summer time), which moves the airflow in a downward direction creating a cool, wind-chill effect. When the fan is rotating clockwise, change its direction by just flipping the fan’s slide switch, is found on the motor housing at the body of the fan. In cooler weather change it back and the fan can make a room feel warmer. When a fan is rotating in a clockwise direction, it forces warm air down from the top of a room to the bottom.
Choosing the Right Fan
The height of the ceiling determines the fan you should choose. There should be at least seven (7) feet between the floor and the blades of the fan. This height prevents people from hitting their head. Buy a fan with a rod that allows the fan to have a hanging depth (the distance between the ceiling and the bottom of the fan) of about 10 inches, this allows the air to circulate (If there’s enough room.).
Fans with a performance grade motor are expensive but are designed for lots of use, operating 12 or more hours a day. A medium grade motor can be used for 12 hours or less a day, and a moderate or economy grade fan can be run for eight hours or less a day.
Summary
In the summer, cooling your home can account for half of your summer power use. Central Air Conditioning comfort comes with a hefty price. A 2.5-ton central system uses about 3500 watts. At 12 cents per kilowatt hour, it costs 42 cents an hour to run your air conditioning unit multiplied over 24 hours, It is a $10 a day expense. Over the course of a month, summer can cost your family $300 or more in extra electricity costs. So run your fans. A ceiling fan can cost around a penny an hour to run. You can run more than 40 ceiling fans for the same cost of your central AC.
