Indoor Air Quality
The Truth About Mold
The Air You Breathe
Comfort By Design
Efficiency & Comfort
According to the EPA, the air inside the average home is up to five times more polluted than the air outside.
Pollen, dust mites, dirt, and mold spores in your home’s air can cause minor health problems like eye and nose irritation,
dizziness, and headaches. Indoor air pollution can also cause more serious problems like respiratory illness, as well as aggravate
allergies and asthma. There are three ways you can improve the air quality in your home:
Preventive Maintenance = $avings!
Take care of your HVAC system, and it will take care of you.
Preventive maintenance agreements (PMAs) are agreements between you and your Air Conditioning Contractors of America (ACCA) quality contractor for scheduled inspections and maintenance of your heating, ventilation, and air conditioning (HVAC) system.
PMAs are generally scheduled for the spring and fall to maintain peak efficiency, help keep utility bills lower, extend the life of your HVAC system, and avert failures. Sometimes PMAs are referred to as “planned maintenance agreements,” “start and checks,” or “preventive service agreements.” Most agreements offered by ACCA contractors cover an inspection of the entire HVAC system and routine maintenance (such as replacing or cleaning filters).
The HVAC system is most likely the single biggest use of energy in your home. In commercial applications where refrigeration is applied (combined with the HVAC systems), huge amounts of energy are used in the building. In fact, over a third of the energy used in the United States is used to heat and cool buildings.
According to the Consortium for Energy Efficiency (CEE), up to 50% more energy can be saved with proper installation, sizing, and maintenance of commercial central air conditioning and heat pumps. Although the CEE study did not measure residential systems, a compelling case can be made that proper maintenance can save homeowners up to 50% as well.
Out of Sight, NOT Out of Mind
The cliché “out of sight, out of mind” is often the reason for neglected maintenance on your HVAC system. HVAC systems are usually installed where they aren’t seen, such as in a section of the basement, a closet, on rooftops, or in mechanical rooms, making them easy to ignore. The systems are simply taken for granted, until they fail. Decreased efficiency, utility overpayment, discomfort, loss of productivity, premature replacement, and higher repair costs are the result.
Getting your HVAC system checked twice annually is just as important as changing the oil in your car every 3,000 miles!
What should you expect your ACCA member service technician to do during a PMA visit?
Spring Visit (preparation for summer season)
Fall Visit (preparation for winter season)
Note: For heat pump applications, winter season inspections repeat a number of the summer procedures plus several additional checks. Maintaining semi-annual PMAs for heat pumps is also important.
What’s your bottom line?
Savings: PMAs typically more than pay for themselves through higher efficiency, lower utility bills, and contractor discounts. PMA customers typically receive a discount on all parts and services performed during the entire year.
Peace of Mind: Predictive maintenance will mean fewer system failures and a longer life for your HVAC equipment.
Priority Service: Should a system failure occur during the heat of the summer or the cold of the winter, customers with PMAs generally receive priority service.
Continuity: Many ACCA contractors assign technicians to specific customers. That way, you get to see and know the same service technician, and he or she becomes more familiar with you and your equipment.
© Air Conditioning Contractors of America Association, Inc., www.acca.org. Reprinted with permission.
There's Good Mold and There's Bad Mold
Molds are the “bleu” in bleu cheese and Roquefort. Molds improve our wine. They produce penicillin and antibiotics and are used widely in the food and beverage industry. Without mold and mold’s decaying mechanism, the natural environment would be overwhelmed with large amounts of dead organic matter.
Despite many harmless and beneficial molds, some molds can be toxic and pose health threats to humans. The Environmental Protection Agency (EPA) cautions that all molds can cause health problems under the right conditions. The word “toxic” refers to mold that produces hazardous compounds, or mycotoxins.
Often included in the list of toxic molds is Stachybotrys Chartarum, a greenish-black mold, which can grow on high-cellulose, low-nitrogen materials such as fiberboard, drywall, paper, dust, and lint – all of which are found in homes – when these materials become wet.
There is evidence that mold exposure can cause the following symptoms:
How to Minimize Mold Growth
Mold is a natural byproduct of the fungi family that thrives when organic substances and water combine under certain circumstances. Mold reproduces via spores that can remain dormant, yet viable, for years. They “come alive” again in the presence of moisture.
HVACR mechanical systems are not generators of mold; their metallic surfaces do not provide the organic matter mold needs to grow. However, systems that are not well maintained could support mold growth. It's important that your system:
If You Suspect Mold in Your Home or Building
The first step is to alert your HVAC contractor and the builder (if the building is relatively new) regarding your concerns. The contractor or builder will inspect for mold. If there is mold, the next step is to identify its type and establish whether it’s toxic. If so, evacuation, abatement, and remediation may be necessary.
The identification of mold requires specialized testing and laboratory analysis. Partly because of media attention to mold issues, mold abatement has become a growth industry, often attracting less than reputable people who may cause more harm than good by not identifying toxic mold, improperly removing it, or charging you for work you don’t need. Check with your state environmental protection or public health agency to find out if mold remediation contractors are required to be certified and licensed.
ACCA member contractors are concerned about the quality of the air you breathe, too, and many have added indoor air quality services to their offerings. If your HVAC contractor does not perform mold analysis, abatement, and remediation, he or she may be able to refer you to a reputable company that is a trained and certified in this kind of work.
© Air Conditioning Contractors of America Association, Inc., www.acca.org. Reprinted with permission.
What's in your air and what can you do about it
Unfortunately, in today’s world, pollution is everywhere. And with the type of cleaning products, manmade goods, and activities undertaken within homes and buildings, indoor environments can become very uncomfortable. Even “fresh,” outdoor air has as many as 30 million dust or pollutant particles per cubic foot.
There are, however, measures you can take to lessen the effects of these particles in your home. Since the home is essentially an enclosed system, heating, ventilation, air conditioning, and refrigeration (HVACR) contractors are able to tackle pollution head-on by moving the air through a high-efficiency air cleaner.
What does an air cleaner do?
At its most basic level, an air cleaner filters out the particles that cause irritation, such as pollen, spores, dust, and other contaminates. In order for any air cleaner to work correctly, the particles need to pass through it. Hence, if the particles are not in the air stream (for example, they’re dust on furniture), an air cleaner won’t remove them. However, a good air cleaner will:
How can an air cleaner help with allergies?
A good air cleaner reduces or removes the irritants that cause allergic symptoms. You may choose a portable air cleaner for smaller spaces or a whole-house air cleaner that works in conjunction with your forced-air system to provide cleaner air throughout your home.
What kinds of residential air cleaners are out there?
There are basically two: furnace-mounted, whole-house units and portable single-room units. Both types of cleaners have different models with varying methods of cleaning the air and capacities for doing so. Your dwelling may help determine the right unit for your needs. A room air cleaner may be best in an apartment, for example, while a whole-house unit might work better with a furnace and air conditioning system. It’s important to note that both room and system air cleaners come in a variety of models, and that not all models use the same technology to clean the air.
Each kind of air cleaner has its pros and cons, which may differ depending on your air-cleaning requirements. Take a look at what your needs are based on your dwelling and allergies and talk to your professional HVACR contractor about the best kind for you.
What are the most effective air cleaners?
Media Air Cleaners
These units use high-efficiency pleated filters, or “media,” to remove about 99% of larger particles, including many allergens. With irritants in the spore and pollen range, they are as effective as HEPA filters but not as effective in filtering out the super-small particulates such as bacteria, viruses, and respirable dust. Media air cleaners are cost effective compared to HEPA filters because the filters are usually less expensive and generally need to be replaced only every one or two years.
HEPA Air Cleaners
HEPA (High Efficiency Particulate Air) cleaners also use high efficiency pleated media to remove particles. To be designated HEPA, an air cleaner must remove 99.97% of all particles 0.3 microns in size (such as dust and mold spores). Due to high cost, operational complications, and other problems, HEPA units are usually seen in residential applications as one-room, portable units. When media in these units need to be replaced, it’s often relatively expensive to do so. Some require charcoal filters that need to be cleaned frequently. Warranties for HEPA cleaners are normally one to three years.
Electrostatic Air Filters
Electrostatic air filters are not recognized as true high-efficiency air cleaners. However, they are generally recognized as being more effective than the standard one-inch throw-away filters. Electrostatic air filters depend on the movement of the air through the filter to give particles a weak electronic charge. Usually, these models are less than 20% efficient, with some models having efficiencies below 5%. They need to be cleaned often, sometimes weekly, to maintain air flow. Electrostatic air filters have warranties ranging from one year to lifetime.
Electronic Air Cleaners
There are two types of electronic air cleaners. Both electrically charge particles and attract them to a collection material. The standard electronic air cleaner will collect charged particles on a specially designed “plate.” Most electronic cleaners can obtain 95% efficiency or higher on various particles when the collection plates and ionizing wires are clean, but they can lose some efficiency as they collect dirt.
A newer technology in electronic air cleaners is called “electronically enhanced media” combining elements of both electronic and media air cleaners. Particles are electrically charged and then collected by the massive air cleaning media of a traditional high-efficiency cleaner. Because the replacement of the media is simple and there are no plates to clean, efficiency is maintained throughout the media’s life. Electronically enhanced media air cleaners are 99% effective in the removal of numerous particle categories. Electronic air cleaners generally have warranties of one to five years.
© Air Conditioning Contractors of America Association, Inc., www.acca.org. Reprinted with permission.
by Jim Herritage, CEM
Before you replace your heating, ventilation, and air conditioning (HVAC) system, there are some things you should know. The first is that a quality installation begins with a professional design.
Most of us don’t think about “design” when we think of heating and cooling, but it’s just as important as a solid architectural design. A professional HVAC contractor won’t simply replace what you have now with new equipment. It’s possible that your existing system wasn’t sized properly to begin with!
To make sure your new HVAC system meets your needs for comfort and energy efficiency, a quality contractor performs a series of calculations that take into account the overall climate where you live; how your home is sited (for example, if it faces south or north); the amount and quality of insulation in walls, basement or crawl space, and attic; how many windows the home has and how efficient they are; other sources of ambient heat, such as kitchen appliances and lights; even landscaping near the house.
These are called “load calculations.” The formulas, which are included in ACCA’s Manual J®, were developed by HVAC experts at ACCA and are the industry standard, often incorporated into local building codes.
Turn to the pros
Why should you care about load calculations? Its simple: an under-sized system can reduce the comfort of your home, use more energy, and not last as long as a properly sized system. An over-sized system will cost more than you need to spend and may contribute to moisture-related problems down the line.
Any contractor who tells you a load calculation isn’t important is not a professional. The professional understands that your year-round comfort is the ultimate goal. In the summer, your air conditioning system not only cools your home’s air (sensible cooling), it removes moisture (latent cooling). In the winter, your heating system must keep you comfortable without causing high utility bills.
Insist that the contractor uses the Manual J residential load calculation procedure. He or she will produce a computerized analysis that indicates just how much heating and cooling capacity your new system should provide. After the installation of your new system is completed, you will receive a copy of the load calculation for your records.
The right equipment
The load calculation also enables the contractor to select the right kind of system. Heating and air conditioning equipment comes in many capacities, configurations, and efficiencies. It’s important that your contractor selects the equipment that will be compatible with your home’s heating and cooling needs.
Ducts, grilles, and registers
A qualified contractor will make sure the duct work in your home is the right size and insulated properly. Properly installed and maintained duct work can last twenty years or more, but time, heat, and humidity can degrade the ducts’ insulation. In addition, ducts may have collected contaminates over the years and need to be cleaned out.
Tell your contractor if some of the rooms in your home have been too hot or too cold, as this could be a sign that the ducts are the wrong size or are dirty. The contractor will evaluate the amount of air each room should get and verify that your duct system is clean and configured to deliver the right air to the right rooms.
Your return air grilles and supply air registers play an important role in providing heating and air conditioning comfort, too. There are times when simply replacing one or more of these devices can cause a noticeable improvement in your home’s thermal comfort.
Return grilles that are undersized can reduce the efficiency of the air conditioning system as well as the comfort in your home. Your contractor will verify that these devices are sized and operating properly and may make suggestions for improved performance.
Select a professional
Buying a new comfort system is a major expense, and most homeowners replace their heating and air conditioning systems only every ten or twenty years. It just makes sense – and cents! – to choose a contractor who knows how to design, install, and service the right equipment for you. Using a professional contractor assures you that your home will be comfortable for many years to come.
Tips for Maximum Efficiency and Comfort
Are you getting the most for your comfort dollar? Or are you paying to heat and cool the neighborhood?
Whether your comfort system is old or new, in a new or old home, in an apartment or a single-family home, there are many little things you can do to optimize its efficiency and minimize your utility bills. They’re definitely worth the small amount of time and expense they take, because in the long run, they’ll save you money.
Whatever the season, you want to keep your comfortable air inside the house. That means caulking and weather stripping doors and windows, around chimneys and flues, and anywhere else inside air can escape. Be sure to check for cracked or broken shingles, crumbling grout, and worn or torn vapor barriers, too.
Inspect the exterior of your home once or twice a year. A good way to remember is to do it when you have your regular, professional HVAC check-up because heating and cooling will be on your mind anyway.
If you’re building a new home or replacing windows, invest in vinyl- or wood-clad insulated (thermopane) windows and storm windows and doors. Then keep them closed whenever the heat or air conditioning is on!
Keep vegetation and debris well away from the outdoor unit of your system. They can block air flow, which forces the system to work harder to produce the same level of comfort. You’ll spend more now … and in a few years, when the equipment fails prematurely and you have to replace it.
However, use vegetation to keep your home cooler in summer and warmer in winter. For example, plant a row of trees on the side of your home the wind usually comes from. They’ll act as wind blocks. Because deciduous trees lose their leaves in the winter, they’ll let in the sun’s light and warmth in winter; in the summer, they provide cooling shade. Do, however, be careful about how close you plant anything to the house, and take into account that trees and shrubs grow. They can block light, and in some areas of the country become highways for such pests as carpenter ants. A local landscape architect, reputable garden center, or the state or county extension agency can help with plant selection and placement.
Set the thermostat at the highest comfortable level in the summer and the lowest comfortable level in the winter. A change in one degree changes energy consumption by about 4%. Humidifiers and dehumidifiers can make a huge difference in how the temperature feels.
Install a programmable thermostat. It will automatically adjust the temperature at night or when you’re not going to be home for a long period of time.
Lights are a source of indoor heat, a problem in the summer. Wherever possible, replace incandescent bulbs and fixtures with compact fluorescents. They use a lot less energy, produce less heat, and last longer. Today’s fluorescents aren’t like those of only a few years ago – you can choose a warm, yellow light similar to incandescent light. You can use them in table lamps, ceiling fixtures (including ceiling fan fixtures), torchieres, and for indoor and outdoor lighting. Some can be used with dimmer switches, too. Avoid halogen lamps. The light is clear and bright, but they create a lot of heat.
In the summer, keep drapes and blinds closed on the sunny side of the house during the day. In the winter, open them to take advantage of solar heat but close them at night to help block cold air (even if you have insulated windows).
Insulate attics, crawl spaces, basements, and walls to the R value recommended for your area. Your HVAC contractor can tell you how much you need. Don’t forget to insulate duct work in un-conditioned space.
Use a gas fireplace or put glass doors on a wood-burning fireplace. (Be sure to check with the manufacturer first – some small fireboxes with zero-clearance flues cannot be outfitted with glass doors.) Keep the damper closed whenever you’re not using the fireplace.
In the summer, do household chores during the coolest part of the day if you can. Cooking, laundry, washing dishes, and heavier work such as vacuuming are examples. Check to see if your electric utility offers time-of-day pricing. That could save you even more money.
Check filters regularly and clean or replace them when needed. Your HVAC technician will tell you how often that’s likely to be based on the manufacturer’s recommendations and local air quality conditions.
Make sure room vents are working properly. Close them at least part-way in rooms you’re not using. Never block them with furniture, pictures, or window coverings.
Consider a zoned system if your home has two or more stories or is very large. A programmable thermostat in each zone can save energy and money.
Then sit back, relax, and enjoy year-round comfort!
It’s All Relative
Proper humidity levels keep you healthier and more comfortable.
Your heating, ventilation, and air conditioning (HVAC) system can do more than heat and cool your home. It can also keep the humidity at a comfortable level in winter and summer. It’s a delicate balance: if it’s too low, you’ll feel the effects of colds, respiratory infections, and asthma more, and some of the furnishings in your home will literally dry out. If it’s too high, you’ll be uncomfortable but mold and mildew will flourish. They love moisture!
Residential HVAC systems balance temperature and humidity. The best person to design a system appropriate for your climate and your comfort needs is a professional ACCA member contractor. He or she understands the science of your home and applies the principles contained in the ACCA design and technical manuals to the design, selection, and installation of an HVAC system that’s right for you.
ACCA manuals are the industry standard, often incorporated into local building codes and endorsed or recommended by the Department of Energy, the Environmental Protection Agency, and equipment manufacturers.
Relatively Speaking …
Relative humidity (RH) is the percent of moisture actually in the air compared to the maximum amount of moisture the air can hold at that temperature. Cold air can hold less moisture than warm air. At 70ºF, air can hold as much as 12 times the amount of moisture as 10ºF air. That’s why it’s usually more humid in the hot summer months.
Most heating systems just heat the air, changing the temperature, not the humidity. Cold air is dry, and forced-air systems and heat pumps pull outside air for heating. When 10°F outside air is heated to 70°F, the humidity level in your home will be the same as the outside airs, around 7%. That’s one reason your skin feels dryer, perhaps even chapped, in the winter. So in dry cold climates, you will probably want to add a humidifier to your heating system.
The effects of bacteria, viruses, fungi, respiratory infections, allergic rhinitis and asthma, and ozone production during the winter can be minimized by higher humidity levels. Studies have shown that wintertime levels of 68°F/60% RH are just as comfortable as 72°F/30% RH; so by increasing the RH and lowering the temperature, you will minimize negative effects while lowering your utility bills.
Because the outside air temperature and RH can change in a short time, even a few hours, a computer-controlled humidifier is probably your best choice. It will automatically adjust for these fluctuations to provide enough moisture for a healthy, comfortable home and minimize or prevent window and cold surface condensation.
Air conditioners pull moisture from the air (HVAC professionals call that “latent heat,” as opposed to “sensible heat,” the temperature) as they cool it, which is one reason you feel better in an air conditioned home. If they didn’t, you’d feel cold and clammy instead of cool and comfortable. In particularly hot and humid climates, however, you may need to augment the dehumidifying capacity of your system.
Very high moisture levels give you that “sticky” feeling and may lead to health problems resulting from the growth of bacteria, viruses, fungi, dust mites, and mold. Air at 78°F/30% RH provides the same level of comfort as does 74°F/70% RH air. In the summer, turning the thermostat up lowers your utility bills, so dehumidifying can save you money as well as add to your comfort.
Although your air conditioning system or stand-alone dehumidifier is designed to remove moisture and decrease the RH levels in your home, in very humid areas of the country, it may not be capable of lowering the levels below 60% RH. In such cases, your ACCA quality contractor may suggest alternative or additional equipment and control strategies.
It’s Your Choice!
The choice is yours: a comfort and health indoor air system, or a furnace/boiler and an air conditioner. Since more than a third of your time is spent in your home, it is important to make the right choice.