Get answers to Frequently Asked Question about Home Air Conditioning & more.
How long should my air conditioner last?
The service life of a central air conditioner is affected by a variety of factors including accumulated runtime hours, system contamination and adherence to a regular maintenance schedule. The average lifespan for a typical modern air conditioner is 12-15 years, but units exposed to extreme summer heat and humidity may only last 10 years or less. In particular, air conditioners operating in the south and southwest are regularly subjected to extreme operating stress, which may significantly reduce the lifecycle of the equipment.
Since dirt, debris and a low refrigerant charge are responsible for the majority of premature failures, it is important to have your air conditioning equipment serviced on a regular basis. Factory trained and NATE certified technicians provide a variety of important services including cleaning the coils, changing filters, adding refrigerant, lubricating moving parts and testing vital components. In addition to extending equipment life, routine maintenance will lower operating costs and improve indoor comfort.
What size air conditioner will I need?
The size of an air conditioner is measured in tonnage, and every ton provides approximately 12,000 BTUs of cooling capacity. Equipment manufacturers produce units in half-ton increments up to five tons for residential applications.
At one time, equipment sizing was more of an art than a science. In fact, there are still many HVAC contractors that use antiquated square-feet-per-ton sizing formulas to establish AC unit capacity. Unfortunately, these methods do not account for the relative quality and efficiency of the materials used in the building’s construction.
In order to provide contractors with a more accurate method of sizing air conditioners, the Air Conditioning Contractors of America (ACCA) developed a protocol designed to determine the precise load requirements for a building and each individual zone. ACCA Manual J is a comprehensive set of formulas that account for critical design criteria such as perimeter tightness, building orientation, windows, local weather conditions, duct leakage and insulation R-values.
Establishing a home’s total load is essential in determining the appropriate capacity for the air conditioning unit. Load calculations have a direct impact on installation costs, performance, efficiency, indoor air quality and total comfort. In new construction and retrofit applications, contractors who do not run a complete set of Manual J load calculations before selecting equipment should be avoided. It is also important to verify that the contractor uses the manufacturer’s extended capacity ratings in areas where the outdoor temperature regularly exceeds baseline design conditions.
Without the benefit of Manual J, most systems will be purposely oversized to avoid complaints of inadequate cooling during extreme summer heat. However, oversized equipment will often short cycle, which results in poor humidity control, uncomfortable temperature fluctuations, and substandard air movement. Higher tonnage units are also more expensive to purchase and install. In essence, the customer pays for capacity they will never use.
Many consumers believe they should replace an aging or failed air conditioner with a new unit of identical capacity. To achieve the highest level of performance at the lowest possible cost, homeowners should always have a qualified air conditioning professional run a complete set of Manual J load calculations before making an equipment purchase.
What efficiency should my air conditioner be?
The Seasonal Energy Efficiency Ratio (SEER) is a uniform standard that was developed to provide consumers with a simple way to compare the relative fuel efficiency of different brands and models of air conditioners. The current federal mandate for new equipment is 13 SEER, which is approximately 23 percent more efficient than a 10 SEER unit installed in the early 2000s.
When selecting equipment efficiency, homeowners should evaluate the relationship between installed cost, projected operating cost and relative payback. In general, older homes with porous envelopes and inferior levels of insulation will benefit the most from high SEER rated equipment. This is especially true for buildings constructed before the implementation of ASHRAE Standard 90.1 in 2004, which provides specific guidelines for energy efficiency standards.
A baseline monthly cost for operating a central air conditioner can be determined by averaging several months of electric bills during the winter when the AC unit is not running. Subtracting the average winter electric bill from the average cost of electricity usage in the summer months will provide a relatively accurate estimate of air conditioner operating expenses. In the alternative, there are a variety of online calculators that can be used to determine AC power consumption based on hours of operation, SEER rating and local utility costs.
A qualified HVAC professional can help analyze your home’s energy consumption characteristics and provide an analysis of the cost benefit for various equipment efficiencies. During the equipment selection process, it is important to recognize the additional benefits of high SEER rated air conditioners, which include superior comfort, reduced maintenance costs and lower noise levels.
What is the best setting for my thermostat?
Indoor comfort is a matter of personal preference, so there is no specific thermostat setting that will satisfy everyone. Lowering the temperature can improve indoor comfort but will consume more electricity as a result. Power costs associated with changing the thermostat are largely dependent on local weather patterns, the efficiency of the unit and the quality of the home’s construction.
As a general rule, the cost of operating an air conditioner can be reduced by up to 5 percent for every degree the thermostat is raised. Homeowners routinely struggle to achieve the proper balance between utility costs and comfort. Proper system design and regular maintenance will help ensure that your AC equipment provides maximum efficiency over an extended lifecycle. Inadequate air flow or a low refrigerant charge can also affect comfort levels and system performance.
Programmable thermostats provide the most effective management of comfort and efficiency. Users can set the thermostat to automatically raise the indoor temperature when the home is unoccupied, and it can be gradually lowered to the desired setting just prior to their arrival later in the day. A programmable thermostat can save up to 20 percent on annual cooling costs when used properly.
How long should my furnace last?
The useful service life of a furnace is dependent on a variety of factors including build quality, maintenance and accumulated runtime hours. However, the average lifecycle of a typical heating appliance is 12-15 years.
The components in a modern furnace are relatively inexpensive and can be easily replaced. Furnace obsolescence usually revolves around the integrity of the heat exchanger and a widening gap in efficiency when compared to newer models. If the heat exchanger cracks or fails, it creates a potentially catastrophic situation that must be immediately addressed by a qualified HVAC professional contractor.
The heat exchanger will usually last about 15 years, depending on the severity of the local weather conditions where the unit is installed. Most manufacturers use aluminum or stainless steel in modern furnace heat exchanger construction. Cast iron heat exchangers can last up to 30 years, but they are used almost exclusively in radiant heating applications
Furnace longevity is primarily affected by proper maintenance. Air flow restrictions cause over-heating, which can reduce the useful life of the heat exchanger. For customers with a maintenance agreement, HVAC technicians will change the filters, adjust the burners, calibrate the blower and perform a variety of other useful services designed to extend the life of the equipment.
What size furnace or heat pump will I need?
Furnace or heat pump sizing is usually determined by the total heating load as established by ACCA Manual J. Qualified HVAC contractors will conduct a complete assessment of the home to determine the impact that windows, doors, insulation, duct leakage, envelope tightness and weather conditions will have on the capacity requirements for the heating appliance.
For areas with extreme summers and relatively mild winters, heat pump sizing will focus primarily on the cooling load since it will be far more substantial than the winter heating load. Furnace capacity is referred to by its BTU input, but it is important to size the system according to the output capacity since it varies by manufacturer and is affected by the air distribution system.
In retrofit applications, furnaces should never be replaced by a unit of the same size without running a complete set of load calculations. Since output capacity is affected by the efficiency of the furnace, an older 100,000 BTU furnace with 60 percent efficiency can be replaced by a modern 80 percent furnace with an 80,000 BTU capacity with no change in the effective heat output.
Oversized systems will cause uncomfortable temperature fluctuations and cold drafts. Additionally, short cycling places the heat exchanger under additional stress and can shorten the service life of the furnace.
What efficiency should my furnace or heat pump be?
Determining system efficiency depends primarily on the homeowner’s installation budget and performance expectation. Heating equipment that carries a higher efficiency rating is generally more expensive to purchase and install. However, over the life of the equipment, the monthly utility savings usually exceed the additional upfront costs by a wide margin. In areas with severe winter weather, a high efficiency heating appliance will have a much lower payback period.
Furnaces are rated according to the Annual Fuel Utilization Efficiency (AFUE) protocol, which is an industry standard used to compare different brands and models of furnaces. A higher AFUE rating is indicative of a more efficient furnace. For example, an 80 percent AFUE rated furnace exhausts only 20 percent of the fuel it consumes in the form of waste gas.
Heat pump heating efficiency is measured by its Heating Seasonal Performance Factor (HSPF). A unit’s HSPF rating is determined by measuring the thermal output of the heat pump relative to its consumed watt-hours. Increasing the HSPF factor from 6.8 to 7.8 can provide savings up to 20 percent on annual heating costs.
What is a dual fuel system and how does it work?
A dual fuel heating system (also known as hybrid heating) provides optimal comfort and performance by including a heat pump and gas furnace in a single system. The unit monitors outdoor conditions and automatically switches the unit to the mode most appropriate for maximum efficiency. A hybrid heating system offers the lowest operating costs among all heating appliances.
Since heat pumps transfer warm air rather than create it through the burn process, they are very effective and efficient when the outdoor temperature remains above freezing. Many homeowners believe that the circulation of heat generated by electricity is more comfortable and evenly distributed. However, the efficiency of a heat pump plummets as the temperature drops, and the quantity of available heat in a given volume of outdoor air is significantly reduced.
When the outdoor temperature approaches 40 degrees Fahrenheit, the gas furnace engages and becomes the primary heating source until the indoor load is satisfied. When considering the purchase of a dual fuel system, it is important to check the efficiency rating of each component, especially the SEER rating of the air conditioning part of the system.
What is the most efficient thermostat setting for heating?
The U.S. Department of Energy recommends that homeowners “set your temperature as low as is comfortable in the winter and as high as is comfortable in the summer.” This ambiguous suggestion reflects the difficulty in determining an optimal thermostat setting.
In general, raising the thermostat 1 degree will save up to 5 percent on monthly heating utility costs. Despite claims to the contrary, lowering the thermostat when the home is vacant will save more energy than will be consumed in the reheating process. For maximum efficiency, homeowners are encouraged to lower the thermostat 5-10 degrees when sleeping or leaving the home for periods over four hours.
The level of comfort can be enhanced by adding insulation, which slows the infiltration of warm air into the living area. Sealing the building perimeter and leaks in the ductwork are also important strategies in raising efficiency and reducing drafts and dramatic temperature fluctuations.
Lowering fuel consumption saves money, and homeowners may elect to offset the savings by maintaining a more comfortable thermostat setting. This can be accomplished through the regular use of a programmable thermostat, which can save up to 20 percent on monthly heating expenses.
Trouble Shooting Questions
Why does my air conditioner keep turning on and off?
The proper operation of an air conditioner is a function of the total thermal load in the livable area as well as the user established thermostat setting. The system engages when a sensor activates a relay as the indoor temperature exceeds the predefined thermostat threshold.
An air conditioning system that is cycling too often is usually a result of one of the following conditions:
- Faulty Thermostat: A thermostat serves as the interface between the homeowner and their air conditioning system. If the sensor or another internal component fails, the thermostat may repeatedly activate the relay regardless of the actual load demand.
- Improper Design: Contractors who select air conditioning equipment without running a complete set of load calculations usually oversize the system in order to avoid complaints of inadequate cooling during extreme heat. Unfortunately, this condition often results in short cycling since the capacity of the unit exceeds the load demand. The air conditioner turns on and off repeatedly, degrading humidity control and reducing indoor comfort.
- Electrical Problems: Short cycling can also be caused by a problem in the equipment’s electrical system. This condition often emerges as a result of a faulty capacitor or an issue with the supply line itself. Air conditioners operate at high voltage, so electrical problems should always be addressed by a licensed HVAC contractor.
Why does my air conditioner leak water?
Condensation is a natural byproduct of the cooling process and the refrigeration cycle. Dehumidification is a normal function of a central air conditioning system, and it helps keep the indoor environment comfortable and healthy.
When an HVAC system is working properly, condensate moisture collects in a drain pan located under the evaporator coil. The system is installed in a way that allows the water to flow down a condensate pipe and eventually exit the home. Any water that begins to accumulate near the air handler should be immediately addressed by an HVAC contractor. Water is corrosive and can shorten the service life of the evaporator coil, heat exchanger and other critical internal parts.
The most common condensation-related problems include:
- Cracked Drain Pan: Some manufacturers incorporate a plastic drain pan in their coil assemblies. Cracks in the pan are common and can result from rough handling during shipping or installation. Older pans can also crack from age and temperature stress.
- Clogged Drain Pipe: Over time, water that drains from the pan will carry sediment and other debris through the drain pipe, which may eventually cause a restriction and clog. Unaddressed obstructions can cause the condensate to back up and overflow from the drain pain. A clogged drain pipe may also lead to serious mold and indoor air quality issues.
Any crack in a drain pipe or drain pan should be repaired immediately, especially if a pipe is leaking inside an interior wall. Signs of a cracked condensate pipe or pan include water marks on a drywall surface or accumulated water on the floor.
My air conditioner keeps freezing up. What does it mean?
When the evaporator coil in an air conditioning system freezes up, it is an indication that superheat and sub-cool may be out of balance. There are two common problems that are most often associated with an iced coil.
- Insufficient Air Flow: A dragging motor, dirty blower wheel, clogged filters, obstructed ductwork or inadequate fan speed can all reduce the air flow across the evaporator coil. When the volume of air is insufficient, the energy transfer process is degraded and the temperature across the coil drops below freezing. In particular, high efficiency filters must be evaluated for excessive static pressure restrictions.
- Low Refrigerant: When a system is low on refrigerant, the evaporator coil becomes too cold, which negatively impacts the efficiency of the heat transfer process until ice begins to accumulate. The ice serves as an insulator that continues to degrade the performance of the system until it eventually stops functioning completely. A regular equipment maintenance program helps ensure that the system will always have a proper refrigerant charge, and any leaks in the system will be promptly repaired by a certified HVAC technician.
Energy Efficiency Questions
What are some ways to save energy on heating and cooling costs?
Escalating utility costs and environmental impact concerns have served to make homeowners more energy conscious. There are a variety of inexpensive strategies designed to improve comprehensive HVAC efficiency without significantly affecting a family’s lifestyle.
- Insulation Upgrade: Homes that were constructed before the mid 2000s often have substandard levels of insulation. If your home has an accessible attic, raising the R-value to meet current Department of Energy standards will decrease the total indoor load, which can substantially reduce HVAC operating costs.
- Preventative Maintenance: Regular seasonal maintenance will help keep your heating and air conditioning system operating efficiently over an extended lifecycle. Factory trained and certified technicians perform a variety of critical inspections, tests and calibrations that will locate small problems before they can affect system performance.
- Change Filters: Dirty filters are the number one cause of performance problems and escalating operating expenses. Cheap, disposable filters should be changed monthly, and high-efficiency filters should be changed at least four times a year.
- Seal the Ductwork: Most homes have an air distribution network that was installed prior to the implementation of national model energy code standards. Duct leakage can reduce HVAC system efficiency by up to 50 percent as conditioned air escapes through gaps and loose connections. Perhaps worse, negative pressure leaks will pull dust, dirt and other contaminants into the living area, which can impact the health of the home’s occupants. HVAC dealers use advanced machinery to seal the interior of existing ductwork to save energy and improve indoor air quality.
How does a programmable thermostat save energy?
A programmable thermostat employs microprocessor technology to adjust the temperature periodically for maximum energy savings. The setting threshold can be adjusted according to a previously established schedule to take advantage of periods when the home is unoccupied. Multiple daily settings can be stored in the device’s memory, and the user can override the current program without disrupting the balance of the daily or weekly programs.
Depending on the severity of the local climate and the setback temperature, a programmable thermostat can save up to 20 percent on annual heating and cooling costs. This is primarily due to the slower thermal loss rate that occurs as the interior temperature moves closer to the outside ambient temperature Advanced models feature an auto-changeover mode, which automatically switches between heating and cooling without requiring any user input.
Past programmable thermostats were often too complex to operate easily, and many homeowners avoided programming the device out of frustration. More recent models have simplified programs and a large touch-screen interface that is user friendly. Advanced programmable thermostats offer remote access, adaptive intelligence and home automation capabilities.
Air Quality Questions
What is considered good IAQ?
Defining “good” indoor air quality can be highly subjective. The occupants of a home can be sensitized to different pollutants, so one person may be highly affected by a particular contaminant level while others may be not affected at all.
In general, developing health issues are a useful indicator of possible IAQ problems, especially if they occur immediately after remodeling, refurnishing or moving into a new home. If you suspect that emerging health-related symptoms in a family member are the result of poor indoor air quality, a doctor or health professional should be consulted immediately.
A family’s lifestyle and activities can also impact the quality of the indoor environment. Humans and domestic animals generate a large quantity of dander, hair and other contaminants. Inadequate ventilation can be identified by condensation forming on windows and walls, loaded furnace filters and stale smelling air. A simple test can be conducted by stepping outside for a few moments, and then reentering the home while trying to locate the source of foul odors.
Poor IAQ reflects negatively on everyone associated with the construction of a building, including the designer, builder and subcontractors. Fortunately, federal regulations relating to the relative quality of the air inside a home or office were established through ASHRAE Standard 62. Reviewed and revised every three years, Standard 62 guidelines were created to “provide indoor air quality that will be acceptable to human occupants and is intended to minimize the potential for adverse health effects.”
Properly equipped HVAC contractors offer detection and remediation services designed to identify unacceptable levels of indoor contaminants and provide strategies for removal and future prevention.
Do I need a humidifier?
Indoor humidity control is an important component in establishing healthy indoor air quality. When the environment is too dry, microscopic organisms and other irritants remain airborne where they canaggravate existing respiratory ailments. Chronically congested nasal passages can weaken the immune system and eventually lead to a variety of illnesses including asthma, allergies and chronic fatigue.
In addition to health concerns, low humidity can result in dry skin conditions, cracked wood in furniture and static shocks. Homes with humidity levels that routinely fall below 35 percent can benefit from adding mechanical humidification to the HVAC system.
Humidifiers are available in configurations that include independently operated fans and bypass units that use the furnace blower to distribute moisture throughout the living area. Different models offer atomized vapor or steam designed for a variety of climates and health conditions.
Improving the humidity level inside a home can often save energy by maintaining acceptable indoor comfort at a lower winter thermostat setting. Flow-through models allow water to run in and out of the unit while a reservoir type humidifier uses a rotating drum to introduce moisture into the system. Central humidifiers are usually connected to the supply side of the duct network.
How often should I have my ducts cleaned?
Normal daily activities can cause a substantial quantity of contaminants to become trapped inside a home without an adequate ventilation pathway. A furnace filter alone cannot capture the total volume of animal dander, human hair, pollen, dirt and other pollutants that can accumulate indoors over time. Without regular cleaning, sensitive components inside the heating and air conditioning system will become coated with layers of unhealthy grime. Fungi and mold spores use these nutrients to thrive and propagate, especially inside the unit’s evaporator coil.
Duct cleaning will remove a significant amount of impurities from the ductwork and other areas that are hidden inside the HVAC system. Technicians examine the interior of the air distribution network from a central location and then attach an industrial strength vacuum to the ductwork. The system is placed under an extreme negative pressure, and a mechanical brush or compressed air whip is used to dislodge any material that remains adhered to the duct surface. In addition to better IAQ, removing ductwork obstructions can help increase system air flow, which will result in lower utility costs, fewer repairs and an extended service life for the equipment.
Duct cleaning frequency is dependent on a variety of factors including the number of occupants in the home, the efficiency of the furnace filter, ventilation pathways, and general cleanliness. Most homes can benefit from a thorough duct cleaning every 3-5 years while the application of an environmentally-friendly biocide to the interior of the ductwork is helpful annually.
How does poor indoor air quality affect my health?
In the course of a day, a typical home accumulates a wide variety of indoor pollutants including debris, pollen, smoke, gasses and harmful chemicals. In buildings without proper humidity control and ventilation, mold and fungi can establish colonies inside the HVAC system. Without a comprehensive IAQ strategy in place, these contaminants are trapped inside the living area and re-circulated through the air distribution network.
While modern homes are most susceptible due to tight perimeter envelopes, older homes can also suffer from poor indoor air quality. Loose ductwork connection and breeches in the material often cause negative pressure leaks. When the heating and cooling system is engaged, dirt, dust and fiberglass can be pulled into the ductwork and deposited in the various rooms inside the home.
The health related consequences of continuous exposure to airborne irritants can be severe, especially in young children and the elderly. Over time, conditions can become chronic and debilitating. Some of the more common disorders caused by substandard indoor air quality include:
- Skin rashes
- Watering and itchy eyes
- Fatigue and general malaise
- Upper respiratory congestion
- Chest congestion
- Sinus infections
- Nose bleeds
- Severe lung disease
A complete indoor air quality strategy that includes filtration, eradication, ventilation and duct cleaning can help keep the air inside a home sanitized, healthy and fresh smelling.
What are some of the common indoor pollutants I should be aware of?
Without a sound approach to indoor air quality, unsafe quantities of potentially dangerous contaminants can accumulate over time, especially in newer homes with sealed perimeters. Hazardous pollutants can be placed in one of two distinct categories.
- Biological Agents: Biological material originated from a living organism. This includes mold, fungi, mildew, viruses, dander, animal saliva, mites, cockroach tissue, pollen and excrement. Viruses, bacteria and pollen are usually carried by people or animals from outdoors directly into the living area. Pets and insects living inside the home are responsible for depositing dander, mites and bodily fluids in areas where they can dry and become airborne. Mold and fungi thrive in the moist interior of the evaporator coil in an HVAC system.
- Volatile Organic Compounds and Gasses: Volatile Organic Compounds (VOCs) are characterized by the action of evaporation at room temperature, which disperses gaseous compounds throughout the living area. Common VOCs include formaldehyde, methylene chloride, benzene, hexane, heptane and styrene. These compounds are found in a variety of furniture products, flooring and paints. Household cleaners, preservatives, glues, waxes, cosmetics, pesticides and cigarette smoke are all sources of VOC out-gassing.
While it is not considered a VOC, radon gas is an invisible, naturally occurring radioactive chemical element found commonly throughout the United States. Radon gas flows from the ground below the foundation or slab and enters the home through gaps in the building’s exterior. Radon can cause serious health conditions, and high levels of exposure have been linked to the development of lung cancer. Periodic radon testing is essential, and unacceptable radon levels should be addressed immediately through an HVAC professional.
Regardless of the nature of the contaminant, a common sense approach can help dramatically improve the quality of the air inside a home or office. Smokers should never be allowed to smoke indoors, and routine house cleaning can help remove the source of many irritants before they become airborne.
Do you provide Freon replacement?
Refrigerant can be added to an existing system, but the process is becoming increasingly problematic. Since a link was established between CFCs and the depletion of the ozone layer in the 1970s, world governments have worked to phase out common refrigerants including R-22. In fact, R-22 is no longer used in modern HVAC equipment manufacturing, and it is scheduled to be completely phased out by 2020.
As R-22 becomes increasingly scarce, prices have risen in anticipation of a very limited supply. The price of R-22 has increased by 500 percent since 2003, and some areas have seen prices quadruple in the last six months.
For many homeowners with R-22 based equipment, failing to repair a refrigerant leak will no longer make financial sense. It may prove to be cost prohibitive to continue to repair aging or obsolete R-22 systems that repeatedly malfunction. Modern air conditioners use R-410A refrigerant, which is not interchangeable with R-22 because of differences in operating pressures.
R-410A has superior thermal transfer properties, which serve to enhance efficiency and lower energy costs. Replacing an R-22 system with a new R-410A based unit can help mitigate the rising expense of equipment service and refrigerant replacement.
What are the benefits of a tune-up for my HVAC system?
When performed by a qualified heating and air conditioning contractor, seasonal tune-ups can provide a variety of important benefits including:
- Better Indoor Comfort: Performance issues can significantly degrade total comfort. Obstructions in the ductwork, low refrigerant levels and loaded filters will compromise system capacity and negatively impact humidity control.
- Lower Energy Costs: While conducting a variety of inspections and tests, technicians will calibrate the HVAC system back to the original manufacturer’s specifications. Improving system performance helps increase equipment efficiency, which results in lower monthly utility costs. Certified service techs are also qualified to identify other energy deficits such as inadequate insulation, envelope gaps and duct leakage.
- Lower Repair Costs: Maintenance programs are designed primarily to ensure the uninterrupted performance of the HVAC system. Tune-ups help locate worn or stressed components before they actually fail. An unexpected malfunction can be disruptive and costly, especially during severe weather when many contractors are dealing with a significant service call backlog.
- Extended Equipment Life: HVAC systems that are properly maintained will accumulate fewer runtime hours when compared to equipment that is neglected. Internal components that are dirty, worn or clogged must work longer and harder to meet the cumulative indoor load. Regular maintenance helps lower the total stress and wear on motors, belts, fans and other moving parts, which can extend the useable service life of the system.
- Improved Safety: A cracked heat exchanger or broken flue pipe can degrade efficiency and may prove to be deadly. Factory trained technicians inspect and test all safety controls and confirm that critical system components are functioning correctly.
How can duct cleaning be beneficial?
A ductwork system that is not properly maintained can negatively impact the performance of a home’s central heating and cooling system. Regular air duct cleaning provides a number of essential benefits including:
- Better Indoor Air Quality: Contaminants that accumulate inside a building that lacks adequate air exchange can aggravate allergies, asthma and other health-related conditions. In duct systems that are neglected, pollutants are often re-circulated continuously throughout the HVAC system and deposited into the different rooms in the home. The duct cleaning process removes a substantial quantity of debris, dirt and other irritants, which will keep the indoor environment cleaner, healthier and smelling fresh.
- Fewer Repairs and Extended Equipment Life: Most HVAC equipment failures occur because of restricted airflow and an accumulation of particulate matter on critical system components. The compromised performance puts further stress on the unit as it struggles to meet the indoor load, especially when weather conditions are severe. As the runtime hours accrue, the system becomes increasingly prone to breakdowns, failures and a shortened lifecycle.
- Reduced Energy Costs: A dirty or clogged evaporator coil will degrade the heat transfer process in a central air conditioner. This condition will cause the compressor and motors to work longer and harder to meet the indoor load. Obstructions in the ductwork increase friction loss, which reduces the quantity and quality of the airflow into the building. When a system runs longer to satisfy the thermostat call, energy costs will steadily increase over time.
How often should I replace my filters and why?
The simple answer is once a month for cheap fiberglass filters and quarterly for high-efficiency filters. However, regular inspections are recommended, and dirty filters should always be changed regardless of the service interval.
Central HVAC filters are designed to capture and remove particulate matter from the air stream while the HVAC system is engaged. MERV ratings determine the quantity and size of the particulate matter the filter is capable of trapping over a given number of passes. Over time, the filter loads up with a considerable quantity of hair, dander, dirt, and dust. HEPA filters are even more efficient and can trap contaminants down to .3 microns in diameter.
When the filter becomes clogged, the system must work harder to satisfy the thermostat call, which can eventually lead to a failure in the blower motor, heat exchanger or compressor. A dirty filter will also add to utility costs since the system remains active for longer periods. Filters that are completely blocked may lead to inadequate air movement, and rooms at the far end of the duct network may not receive any conditioned air at all.
It is particularly important to inspect high-efficiency filters regularly since they will accumulate pollutants that are not visible to the naked eye. Reusable filters should also be cleaned at least on a quarterly basis in a solution recommended by the manufacturer.
What is SEER and EER and what is the difference between them?
Both SEER and EER ratings provide a comparative measurement of the relative efficiency of appliances that utilize the refrigeration cycle to provide conditioned air. In both instances, a higher rating number identifies more efficient operation.
The differences in the measurements from a technical standpoint can be defined as follows:
- Energy Efficiency Ratio (EER): The EER rating for air conditioning is the measurement of the total cooling capacity of the equipment in British Thermal Units (BTUs) per hour relative to the total electrical input in watts. EER testing is performed at a specific outdoor temperature and 50 percent relative humidity.
- Seasonal Energy Efficiency Ratio (SEER): The SEER rating for an air conditioner measures the total cooling output during its typical annual usage period divided by the total power consumed in watts. SEER differs from EER in that it incorporates a variety of outdoor temperature settings in the testing protocol to more accurately reflect the actual conditions that central air conditioning systems operate in. In general, the SEER rating of an air conditioner is more useful for comparative purposes than its EER rating.
In southern climates that experience severe summer heat, homeowners should identify the unit’s extended efficiency ratings, which are usually provided by the equipment manufacturer. As the outdoor temperature rises, system efficiency is degraded, and two units with identical SEER ratings may have dramatically different performance characteristics at 105 degrees ambient.
What is a BTU?
In its basic form, a British Thermal Unit (BTU) is a measurement of heat energy. From a lab perspective, one BTU is equivalent to the amount of energy required to raise 1 pound of water 1 degree Fahrenheit.
BTU is a common term in the HVAC industry used to define the measurement of the output capacity of heating and cooling equipment. A “ton” of air conditioning refers to roughly 12,000 BTUs of cooling capacity output.
What is HSPF and what does AFUE mean?
Both HSPF and AFUE are federal standards designed to provide consumers with a simple method to evaluate the efficiency of competing heating appliances. Each of the ratings can be further defined as follows:
- AFUE: The Annual Fuel Utilization Efficiency (AFUE) rating can be used to compare the operating costs of different furnace brands and models. The rating is expressed in percentages, and it is a direct measurement of the amount of fuel a furnace converts into heat energy. For example, a furnace with an 80 AFUE rating exhausts 20 percent of the energy it consumes in the form of waste gas while 80 percent is delivered in the form of heat. A higher AFUE rating is always indicative of a more efficient furnace.
- HSPF: The Heating Seasonal Performance Factor (HSPF) is a rating that is specific to the heating portion of heat pump operation. HSPF measures the relative efficiency of the unit while in the heating mode. The actual rating number is derived by calculating the heat output in BTUs relative to the watt-hours consumed. A higher HSPF rating means the unit has better heating efficiency. It is important to recognize that heat pump heating efficiency declines dramatically as the outdoor temperature approaches freezing.
What is a MERV rating?
The Minimum Efficiency Reporting Value (MERV) was developed by AHRAE in the late 1980s to provide a method for consumers to compare the relative effectiveness of different styles of central HVAC filters. The test protocol includes introducing particles of varying sizes are into a sealed chamber, and the filter is subsequently evaluated based on its total capture percentage. MERV ratings range from one to 16, and a higher MERV rating indicates that the filter is more efficient in removing small sized particulate matter when compared to a filter with a lower MERV rating.
While filter efficiency is important, homeowner’s must recognize that a high-efficiency filter can become extremely resistant as it continues to load up with dirt, debris and ultra-fine particulate matter. A system that encounters too much overall resistance will not perform properly, which can lead to higher utility costs, degraded indoor comfort and more frequent repairs. In general, a filter with a MERV rating between eight and 11 is most appropriate for residential systems, but it is important to consult a qualified HVAC contractor to ensure your equipment can accommodate higher efficiency filters.
Inspecting and changing filters on a regular basis can help improve a home’s indoor air quality and extend equipment life by keeping the internal components clean and performing at peak efficiency.
How do I know if I have an existing warranty of my furnace, air conditioner or HVAC System?
To verify that an existing furnace, air conditioner or heat pump is still under the manufacturer’s warranty, the homeowner should locate the unit’s serial and model numbers. For split system equipment, the condensing unit and air handler will be listed separately for warranty purposes. On every piece of HVAC equipment there is a label or metal plate that includes identifying numbers and a variety of related performance information such as electrical and mechanical specifications.
The installing HVAC contractor typically retains detailed documentation for the systems they have installed, which includes model and serial numbers. If the contractor is no longer in business, the local equipment distributor may have kept their own warranty related records. In a worst case scenario, the manufacturer will have a historical record of the equipment from the manufacturing date through the installation date.
Homeowner’s are encouraged to retain all paperwork and receipts related to the installation and the date the unit was placed into service. When the manufacturer is provided with purchase information and serial numbers, they can confirm the current warranty status of your equipment. A new warranty registration should always be submitted immediately after the unit installation is finished.
Most of the major heating and air conditioning manufacturers in the U.S. provide a minimum 5-year warranty on the compressor and other parts. However, units that are less than ten years old may still be eligible for some level of coverage, especially on high-end equipment. Homeowners should recognize that standard equipment warranties rarely cover the cost of labor.
Which Bryant equipment will best fit my home?
There are many factors that affect the sizing and specifications of your system, including square footage, insulation, window surface and configuration, geographic location of your home, duct sizing and arrangement, and many others. Goose Creek can perform an in-home load analysis to determine which equipment combinations will perfectly suit your home and your family’s needs. Depending upon the construction of your home, one (1) ton of air conditioning can cool anywhere from 300 to 800 square feet of home. The only way to insure the size of the system you purchase will be large enough to cool your home, but not any larger than you need, is to have your home’s individual heating and cooling needs evaluated by a licensed professional.
When replacing an outdoor unit should the indoor unit also be replaced?
A new central air conditioning system should always include the following matched components:
- Outdoor condensing unit
- Indoor air handler or furnace
- Matched evaporator coil
- Appropriately sized refrigerant tubing
- Appropriately sized electrical system
Unfortunately, unscrupulous contractors may recommend replacing the outdoor condensing unit and connecting it to an existing evaporator coil and air handler. This occurs most often when the homeowner is on a tight budget and the failure is compressor related.
This practice is highly unethical and may be illegal. Since 2006, the Department of Energy has required that all new central air conditioning installations meet 13 SEER guidelines. A mismatched condensing unit and condensing coil will result in substantially diminished efficiency in a best case scenario.
In a more likely outcome, the compressor fails prematurely in the new unit, and the warranty is voided as a result. The Air Conditioning and Refrigeration Institute (ARI) publishes data that contractors use to confirm the compatibility of different brands of condensing units with third party coil manufacturers.
Since all new condensing units are designed around the operating pressure requirements of R-410A refrigerant, connection to an old R-22 evaporator coil will void the manufacturer’s warranty and may result in serious damage to both the condenser and the coil.
What kind of system is better: ductless heat pump of a central HVAC system?
HVAC equipment is available in a variety of configurations tailored for many different applications. The appeal of a central HVAC system compared to a ductless heat pump is dependent on the application, efficiency expectation, architecture and personal preference.
Conventional heating and air conditioning systems are based around a single unit designed to service an entire house or a specific, large zone. Regardless of whether the equipment is installed as a split system, package unit or heat pump, an intricate air distribution network is required to deliver conditioned air into the various rooms of the home.
Central HVAC systems are cost effective, relatively quiet, visually unobtrusive and reliable, but the duct system can degrade efficiency and may accumulate dust, dirt and debris over time. In many instances, the building architecture is compromised because of the ducting requirement. Perhaps most importantly, proper system design is critical to address the different load requirements in the various zones.
Ductless split systems eliminate the need for ductwork since every indoor unit contains a separate fan coil. The indoor enclosure can be hung from a wall or installed in a ceiling. Some homeowners find the wall units are too large and obtrusive, especially when they placed in smaller rooms.
Since there is no associated air distribution system, ductless heat pumps provide point-of use heating and cooling. Users enjoy the benefit of complete zoned temperature control as each indoor unit operates independently. Ductless systems use proprietary inverter technology, which regulates compressor operation to provide the highest equipment SEER ratings in the industry.
Available in mini split or multi split configurations, ductless heat pumps are especially effective for room additions, attic build-outs, garage conversions, media rooms and any area requiring supplemental heating and cooling.
How can I improve air quality and circulation?
Energy conservation science has developed dramatically over the past two decades, and the effort has led to construction standards that ensure that every new building will have a tight perimeter with minimal leakage. Modern homes are substantially more efficient, but the unintended consequence has been a significant reduction in the rate of natural ventilation. As the rate of childhood asthma continues to rise, it is no wonder the Environmental Protection Agency has listed poor indoor air quality as a top five environmental hazard.
A qualified HVAC contractor will work with the homeowner to develop a comprehensive IAQ strategy that includes filtration, eradication, duct cleaning and ventilation.
Mechanical ventilation devices draw a continuous stream of fresh air into the home based around ASHRAE Standard 62.2. Controlled ventilation simultaneously exhausts accumulated contaminants outdoors, which leaves the air in the interior of the home cleaner and fresh smelling. Circulation is improved by the constant mixing of air from different rooms in the home.
Ventilation devices are available in three specific configurations based on features, benefits and budget expectations:
- Passive Units: Passive ventilation units are tied directly into the HVAC system and operate through the action of the blower in the air handler. When the equipment is engaged, fresh air is drawn from the outdoors into the return side of system, and the increased pressure forces stale indoor air through an exhaust network that terminates outside.
- Active Units: Mechanical Ventilators are self-powered and include a fan that draws a constant flow of fresh air into the living area from outdoors. These devices use very little electricity and can be calibrated precisely to ensure the indoor air conforms to federal standards.
- Energy Recovery Ventilators: ERVs include technology designed to recover some of the energy that is lost through the air exchange process. This helps condition the temperature of the incoming fresh air to more closely match the indoor environment. In addition to saving energy, ERVs also improve indoor comfort.