According to the InterNACHI Residential Standards of Practice, a home inspection is a non-invasive, visual examination of a residential dwelling that is designed to identify observed material defects within specific components of that dwelling. Part of the home inspection includes the inspection, identification and description of the heating system, which includes heat pumps.
The inspector is required to inspect the heating systems using normal operating controls, and describe the energy source and heating method. The inspector’s report shall describe and identify, in written format, the inspected heating system, and shall identify material defects observed.
In order to perform an inspection according to the Standards of Practice, an inspector must apply the knowledge of what he/she understands about the different types of residential heating systems. To inspect and identify a particular heating system, describe its heating method, and identify any material defects observed, an inspector should be able to explain and discuss with their client: 

• the heating system; 
• its heating method; 
• its type or identification; 
• how the heating system operates; 
• how to maintain it; and 
• the common problems that may be found.  

The inspector must be able to thoroughly examine a heating system, understand how a particular heating system operates, and analyze and draw conclusions as to its apparent condition. An inspector should also be able to justify his/her observations, opinions and recommendations that were written in the inspection report. 
Here, we cover some fundamentals of a particular heating system called a heat pump using non-invasive, visual-only inspection techniques. We also discuss its defrost cycle. It is up to the inspector’s judgment as to how detailed the inspection and report will be. For example, the inspector is not required to determine the capacity or BTU of the inspected heating system, but many inspectors record that detailed information in their reports. 

How it Operates
When a heat pump is operating in the heating mode or heat cycle, the outdoor air is relatively cool and the outdoor coil acts as an evaporator. Under certain conditions of temperature and relative humidity, frost might form on the surface of the outdoor coil. The layer of frost will interfere with the operation of the heat pump by making the pump work harder and, therefore, inefficiently. The frost must be removed. A heat pump has a cycle called a defrost cycle, which removes the frost from the outdoor coil.
A heat pump unit will defrost regularly when frost conditions occur. The defrost cycle should be long enough to melt the ice, and short enough to be energy-efficient.
In the defrost cycle, the heat pump is automatically operated in reverse, for a moment, in the cooling cycle. This action temporarily warms up the outdoor coil and melts the frost from the coil. In this defrost cycle, the outdoor fan is prevented from turning on when the heat pump switches over, and the temperature rise of the outdoor coil is accelerated and increased.
The heat pump will operate in the defrost cycle until the outdoor coil temperature reaches around 57° F. The time it takes to melt and remove accumulated frost from an outdoor coil will vary, depending on the amount of frost and the internal timing device of the system.
 
Interior Heating Element 
During this defrost cycle with older heat pumps, the indoor unit might be operating with the fan blowing cool air. To prevent cool air from being produced and distributed inside the house, an electric heating element can be installed and engaged at the same time as the defrost cycle. In defrost mode, this heating element will automatically turn on, or the interior blower fan will turn off. The heating component is wired up to the second stage of a two-stage thermostat.
 
The Typical Cycle 
The components that make up the defrost cycle system includes a thermostat, timer and a relay. There is a special thermostat or sensor of the defrost cycle system, often referred to as the frost thermostat. It is located on the bottom of the outdoor coil where it can detect the temperature of the coil.
 
When the outdoor coil temperature drops to around 32° F, the thermostat closes the circuit and makes the system respond. This causes an internal timer to start. Many heat pumps have a generic timer that energizes the defrost relays at certain intervals of time. Some generic timers will energize the defrost cycle every 30, 60 and 90 minutes.
 
The defrost relays turn on the compressor, switch the reversing valve of the heat pump, turn on the interior electric heating element, and stop the fan at the outdoor coil from spinning. The unit is now in the defrost cycle.
 
The unit remains in the defrost cycle (or cooling cycle) until the thermostat on the bottom of the outdoor coil senses that the outdoor coil temperature has reached about 57° F. At that temperature, the outdoor coil should be free of frost. The frost thermostat opens the circuit, stops the timer, then the defrost cycle stops, the internal heater turns off, the valve reverses, and the unit returns to the heating cycle. A typical defrost cycle might run from 30 seconds to a few minutes. The defrost cycles should repeat regularly at timed intervals. An inspector should not observe a rapid cycling of the defrost operation.
 
In summary, certain conditions can force a heat pump into a defrost cycle (or cooling cycle) where the fan in the outdoor coil is stopped, the indoor fan is stopped or electric heat is turned on, the frost melts and is removed from the outdoor coils. When the frost thermostat is satisfied or a certain pre-set time period elapses, the outdoor fan comes back on, and the heat pump goes back into the heating cycle.
 
One problem of many older heat pump systems is that the unit will operate in the defrost cycle regardless of whether ice is present. On these systems, if it’s cold outside, the defrost cycle might turn on when it is not needed.
 
If the defrost cycle is not functioning properly, the outdoor coil will appear like a big block of ice, making the unit non-functional. Damage could result if the heat pump operates without a functional, normal-operating defrost cycle.
 
Causes of Frost
There are many reasons why an inspector might find frost and ice stuck on an outdoor coil of a heat pump that is not properly defrosting.  

The cause of the frost and ice problem may include: 

• a bad reversing valve;
• a damaged outdoor coil;
• a wiring problem;
• a bad thermostat;
• a leak in the refrigerant;
• a dirty outdoor coil covered with grass, dirt, debris and/or pet hair; 
• a fan that won’t turn on; 
• a fan installed backwards with the blades running in the wrong direction; 
• a motor operating in the incorrect direction; and/or 
• a replacement fan motor spinning at a very low rpm.  

Diagnosing apparent problems with the defrost cycle of a heat pump is beyond the scope of a home inspection.


The Best Techniques
There are three cycles of a heat pump:  heating, cooling and defrost cycles. We learned about the defrost cycle of a heat pump. According to the InterNACHI Standards of Practice, the inspector is required to inspect the heating systems using normal operating controls and describe the heating method. The inspector’s report shall describe and identify, in written format, the inspected heating system, and shall identify material defects observed.
 
To learn how to properly inspect a heat pump system using the best non-invasive, visual-only inspection techniques as required by the Standards of Practice, an inspector should be professionally trained.   

​by Nick Gromicko, CMI® and Ben Gromicko

What Is Asbestos?
Asbestos is a mineral fiber that can be positively identified only with a special type of microscope. There are several types of asbestos fibers. In the past, asbestos was added to a variety of products to strengthen them and to provide heat insulation and fire resistance. InterNACHI inspectors can supplement their knowledge with the information offered in this guide. 
How Can Asbestos Affect Human Health?
From studies of people who were exposed to asbestos in factories and shipyards, we know that breathing high levels of asbestos fibers can lead to an increased risk of lung cancer in the forms of mesothelioma, which is a cancer of the lining of the chest and the abdominal cavity, and asbestosis, in which the lungs become scarred with fibrous tissue.The risk of lung cancer and mesothelioma increase with the number of fibers inhaled. The risk of lung cancer from inhaling asbestos fibers is also greater if you smoke. People who get asbestosis have usually been exposed to high levels of asbestos for a long time. The symptoms of these diseases do not usually appear until about 20 to 30 years after the first exposure to asbestos. 
Most people exposed to small amounts of asbestos, as we all are in our daily lives, do not develop these health problems. However, if disturbed, asbestos material may release asbestos fibers, which can be inhaled into the lungs. The fibers can remain there for a long time, increasing the risk of disease. Asbestos material that would crumble easily if handled, or that has been sawed, scraped, or sanded into a powder, is more likely to create a health hazard. 


Where Would Asbestos Be Found, and When Can it Be a Problem?
Most products made today do not contain asbestos. Those few products made which still contain asbestos that could be inhaled are required to be labeled as such. However, until the 1970s, many types of building products and insulation materials used in homes contained asbestos. 
Common products that might have contained asbestos in the past, and conditions which may release fibers, include:

• steam pipes, boilers and furnace ducts insulated with an asbestos blanket or asbestos paper tape. These materials may release asbestos fibers if damaged, repaired, or removed improperly;
• resilient floor tiles (vinyl asbestos, asphalt and rubber), the backing on vinyl sheet flooring, and adhesives used for installing floor tile. Sanding tiles can release fibers, and so may scraping or sanding the backing of sheet flooring during removal;
• cement sheet, millboard and paper used as insulation around furnaces and wood-burning stoves. Repairing or removing appliances may release asbestos fibers, and so may cutting, tearing, sanding, drilling, or sawing insulation;
• door gaskets in furnaces, wood stoves and coal stoves. Worn seals can release asbestos fibers during use;
• soundproofing or decorative material sprayed on walls and ceilings. Loose, crumbly or water-damaged material may release fibers, and so will sanding, drilling or scraping the material;
• patching and joint compounds for walls and ceilings, and textured paints. Sanding, scraping, or drilling these surfaces may release asbestos fibers;
• asbestos cement roofing, shingles and siding. These products are not likely to release asbestos fibers unless sawed, dilled or cut;
• artificial ashes and embers sold for use in gas-fired fireplaces, and other older household products, such as fireproof gloves, stove-top pads, ironing board covers and certain hairdryers; and
• automobile brake pads and linings, clutch facings and gaskets.

Where Asbestos Hazards May Be Found in a Home

• Some roofing and siding shingles are made of asbestos cement.
• Houses built between 1930 and 1950 may have asbestos as insulation.
• Asbestos may be present in textured paint and in patching compounds used on wall and ceiling joints. Their use was banned in 1977.
• Artificial ashes and embers sold for use in gas-fired fireplaces may contain asbestos.
• Older products, such as stove-top pads, may have some asbestos compounds.
• Walls and floors around wood-burning stoves may be protected with asbestos paper, millboard or cement sheets.
• Asbestos is found in some vinyl floor tiles and the backing on vinyl sheet flooring and adhesives.
• Hot water and steam pipes in older houses may be coated with an asbestos material or covered with an asbestos blanket or tape.
• Oil and coal furnaces and door gaskets may have asbestos insulation.
  
  

What Should Be Done About Asbestos in the Home?
If you think asbestos may be in your home, don't panic.  Usually, the best thing to do is to leave asbestos material that is in good condition alone. Generally, material in good condition will not release asbestos fibers. There is no danger unless the asbestos is disturbed and fibers are released and then inhaled into the lungs. Check material regularly if you suspect it may contain asbestos. Don't touch it, but look for signs of wear or damage, such as tears, abrasions or water damage. Damaged material may release asbestos fibers. This is particularly true if you often disturb it by hitting, rubbing or handling it, or if it is exposed to extreme vibration or air flow. Sometimes, the best way to deal with slightly damaged material is to limit access to the area and not touch or disturb it. Discard damaged or worn asbestos gloves, stove-top pads and ironing board covers. Check with local health, environmental or other appropriate agencies to find out proper handling and disposal procedures. If asbestos material is more than slightly damaged, or if you are going to make changes in your home that might disturb it, repair or removal by a professional is needed. Before you have your house remodeled, find out whether asbestos materials are present. 

How to Identify Materials That Contain Asbestos
You can't tell whether a material contains asbestos simply by looking at it, unless it is labeled. If in doubt, treat the material as if it contains asbestos, or have it sampled and analyzed by a qualified professional. A professional should take samples for analysis, since a professional knows what to look for, and because there may be an increased health risk if fibers are released. In fact, if done incorrectly, sampling can be more hazardous than leaving the material alone. Taking samples yourself is not recommended. If you nevertheless choose to take the samples yourself, take care not to release asbestos fibers into the air or onto yourself. Material that is in good condition and will not be disturbed (by remodeling, for example) should be left alone. Only material that is damaged or will be disturbed should be sampled. 
 
Anyone who samples asbestos-containing materials should have as much information as possible on the handling of asbestos before sampling and, at a minimum, should observe the following procedures:

• Make sure no one else is in the room when sampling is done.
• Wear disposable gloves or wash hands after sampling.
• Shut down any heating or cooling systems to minimize the spread of any released fibers.
• Do not disturb the material any more than is needed to take a small sample.
• Place a plastic sheet on the floor below the area to be sampled.
• Wet the material using a fine mist of water containing a few drops of detergent before taking the sample. The water/detergent mist will reduce the release of asbestos fibers.
• Carefully cut a piece from the entire depth of the material using a small knife, corer or other sharp object. Place the small piece into a clean container (a 35-mm film canister, small glass or plastic vial, or high-quality resealable plastic bag).
• Tightly seal the container after the sample is in it. 
• Carefully dispose of the plastic sheet. Use a damp paper towel to clean up any material on the outside of the container or around the area sampled. Dispose of asbestos materials according to state and local procedures.
• Label the container with an identification number and clearly state when and where the sample was taken.
• Patch the sampled area with the smallest possible piece of duct tape to prevent fiber release.
• Send the sample to an asbestos analysis laboratory accredited by the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST). Your state or local health department may also be able to help.  

How to Manage an Asbestos Problem 
If the asbestos material is in good shape and will not be disturbed, do nothing! If it is a problem, there are two types of corrections: repair and removal. Repair usually involves either sealing or covering asbestos material. Sealing (encapsulation) involves treating the material with a sealant that either binds the asbestos fibers together or coats the material so that fibers are not released. Pipe, furnace and boiler insulation can sometimes be repaired this way. This should be done only by a professional trained to handle asbestos safely. Covering (enclosure) involves placing something over or around the material that contains asbestos to prevent the release of fibers. Exposed insulated piping may be covered with a protective wrap or jacket. With any type of repair, the asbestos remains in place. Repair is usually cheaper than removal, but it may make removal of asbestos later (if found to be necessary) more difficult and costly. Repairs can either be major or minor. Major repairs must be done only by a professional trained in methods for safely handling asbestos. Minor repairs should also be done by professionals, since there is always a risk of exposure to fibers when asbestos is disturbed.
 
Repairs 
Doing minor repairs yourself is not recommended, since improper handling of asbestos materials can create a hazard where none existed. If you nevertheless choose to do minor repairs, you should have as much information as possible on the handling of asbestos before doing anything. Contact your state or local health department or regional EPA office for information about asbestos training programs in your area. Your local school district may also have information about asbestos professionals and training programs for school buildings. Even if you have completed a training program, do not try anything more than minor repairs. Before undertaking minor repairs, carefully examine the area around the damage to make sure it is stable. As a general rule, any damaged area which is bigger than the size of your hand is not considered a minor repair. Before undertaking minor repairs, be sure to follow all the precautions described previously for sampling asbestos material. Always wet the asbestos material using a fine mist of water containing a few drops of detergent. Commercial products designed to fill holes and seal damaged areas are available. Small areas of material, such as pipe insulation, can be covered by wrapping a special fabric, such as re-wettable glass cloth, around it. These products are available from stores (listed in the telephone directory under "Safety Equipment and Clothing") which specialize in asbestos materials and safety items. 
Removal is usually the most expensive method and, unless required by state or local regulations, should be the last option considered in most situations. This is because removal poses the greatest risk of fiber release. However, removal may be required when remodeling or making major changes to your home that will disturb asbestos material. Also, removal may be called for if asbestos material is damaged extensively and cannot be otherwise repaired. Removal is complex and must be done only by a contractor with special training. Improper removal may actually increase the health risks to you and your family.
 
Asbestos Professionals: Who Are They and What Can They Do? 
Asbestos professionals are trained in handling asbestos material. The type of professional will depend on the type of product and what needs to be done to correct the problem. You may hire a general asbestos contractor or, in some cases, a professional trained to handle specific products containing asbestos.  
Asbestos professionals can conduct inspections, take samples of suspected material, assess its condition, and advise on the corrections that are needed, as well as who is qualified to make these corrections. Once again, material in good condition need not be sampled unless it is likely to be disturbed. Professional correction or abatement contractors repair and remove asbestos materials.  
Some firms offer combinations of testing, assessment and correction. A professional hired to assess the need for corrective action should not be connected with an asbestos-correction firm. It is better to use two different firms so that there is no conflict of interest. Services vary from one area to another around the country.  
The federal government offers training courses for asbestos professionals around the country. Some state and local governments also offer or require training or certification courses. Ask asbestos professionals to document their completion of federal or state-approved training. Each person performing work in your home should provide proof of training and licensing in asbestos work, such as completion of EPA-approved training. State and local health departments or EPA regional offices may have listings of licensed professionals in your area. If you have a problem that requires the services of asbestos professionals, check their credentials carefully. Hire professionals who are trained, experienced, reputable and accredited -- especially if accreditation is required by state or local laws. Before hiring a professional, ask for references from previous clients. Find out if they were satisfied. Ask whether the professional has handled similar situations. Get cost estimates from several professionals, as the charges for these services can vary. 
Though private homes are usually not covered by the asbestos regulations that apply to schools and public buildings, professionals should still use procedures described in federal or state-approved training. Homeowners should be alert to the chance of misleading claims by asbestos consultants and contractors. There have been reports of firms incorrectly claiming that asbestos materials in homes must be replaced. In other cases, firms have encouraged unnecessary removal or performed it improperly. Unnecessary removal is a waste of money. Improper removal may actually increase the health risks to you and your family. To guard against this, know what services are available and what procedures and precautions are needed to do the job properly. 
In addition to general asbestos contractors, you may select a roofing, flooring or plumbing contractor trained to handle asbestos when it is necessary to remove and replace roofing, flooring, siding or asbestos-cement pipe that is part of a water system. Normally, roofing and flooring contractors are exempt from state and local licensing requirements because they do not perform any other asbestos-correction work.
Asbestos-containing automobile brake pads and linings, clutch facings and gaskets should be repaired and replaced only by a professional using special protective equipment. Many of these products are now available without asbestos.

If you hire an InterNACHI® inspector who is trained in asbestos inspection:

• Make sure that the inspection will include a complete visual examination, and the careful collection and lab analysis of samples. If asbestos is present, the inspector should provide a written evaluation describing its location and extent of damage, and give recommendations for correction or prevention.
• Make sure an inspecting firm makes frequent site visits if it is hired to assure that a contractor follows proper procedures and requirements. The inspector may recommend and perform checks after the correction to assure that the area has been properly cleaned.

If you hire a corrective-action contractor:

• Check with your local air pollution control board, the local agency responsible for worker safety, and the Better Business Bureau. Ask if the firm has had any safety violations. Find out if there are legal actions filed against it.
• Insist that the contractor use the proper equipment to do the job. The workers must wear approved respirators, gloves and other protective clothing.
• Before work begins, get a written contract specifying the work plan, cleanup, and the applicable federal, state and local regulations which the contractor must follow (such as notification requirements and asbestos disposal procedures). Contact your state and local health departments, EPA regional office, and the Occupational Safety and Health Administration's regional office to find out what the regulations are. Be sure the contractor follows local asbestos removal and disposal laws. At the end of the job, get written assurance from the contractor that all procedures have been followed.
• Assure that the contractor avoids spreading or tracking asbestos dust into other areas of your home. They should seal off the work area from the rest of the house using plastic sheeting and duct tape, and also turn off the heating and air conditioning system. For some repairs, such as pipe insulation removal, plastic bags may be adequate. They must be sealed with tape and properly disposed of when the job is complete.
• Make sure the work site is clearly marked as a hazardous area. Do not allow household members or pets into the area until work is completed.
• Insist that the contractor apply a wetting agent to the asbestos material with a hand sprayer that creates a fine mist before removal. Wet fibers do not float in the air as easily as dry fibers and will be easier to clean up.
• Make sure the contractor does not break removed material into smaller pieces. This could release asbestos fibers into the air. Pipe insulation was usually installed in pre-formed blocks and should be removed in complete pieces.
• Upon completion, assure that the contractor cleans the area well with wet mops, wet rags, sponges and/or HEPA (high-efficiency particulate air) vacuum cleaners. A regular vacuum cleaner must never be used. Wetting helps reduce the chance of spreading asbestos fibers in the air. All asbestos materials and disposable equipment and clothing used in the job must be placed in sealed, leakproof, and labeled plastic bags. The work site should be visually free of dust and debris. Air monitoring (to make sure there is no increase of asbestos fibers in the air) may be necessary to assure that the contractor's job is done properly. This should be done by someone not connected with the contractor. 

Caution!

Do not dust, sweep or vacuum debris that may contain asbestos. These actions will disturb tiny asbestos fibers and may release them into the air. Remove dust by wet-mopping or with a special HEPA vacuum cleaner used by trained asbestos contractors.

Home Buyer's and Seller's Guide to Radon 
The EPA recommends:

• If you are buying a home or selling your home, have it tested for radon. 
  
  
• For a new home, ask if radon-resistant construction features were used and if the home has been tested. 
  
  
• Fix the home if the radon level is 4 picoCuries per liter (pCi/L) or higher. 
  
  
• Radon levels less than 4 pCi/L still pose a risk, and in many cases, may be reduced. 
  
  
• Take steps to prevent device interference when conducting a radon test.

The EPA estimates that radon causes thousands of cancer deaths in the U.S. each year.
 * Radon is estimated to cause about 21,000 lung cancer deaths per year.
The numbers of deaths from other causes are taken from the Centers for Disease Control and Prevention's 1999-2001 National Center for Injury Prevention and Control Report and 2002 National Safety Council Reports.
Radon is a cancer-causing, radioactive gas.
You cannot see, smell or taste radon. But it still may be a problem in your home.  When you breathe air containing radon, you increase your risk of getting lung cancer.  In fact, the Surgeon General of the United States has warned that radon is the second leading cause of lung cancer in the United States today.  If you smoke and your home has high radon levels, your risk of lung cancer is especially high.
You should test for radon.
Testing is the only way to find out your home's radon levels. The EPA and the Surgeon General recommend testing all homes below the third floor for radon.
You can fix a radon problem.
If you find that you have high radon levels, there are ways to fix a radon problem. Even very high levels can be reduced to acceptable levels.
If You Are Selling a Home...
The EPA recommends that you test your home before putting it on the market and, if necessary, lower your radon levels. Save the test results and all information you have about steps that were taken to fix any problems. This could be a positive selling point. 
If You Are Buying a Home...
The EPA recommends that you know what the indoor radon level is in any home you are considering buying.  Ask the seller for their radon test results.  If the home has a radon-reduction system, ask the seller for information they have about the system.
If the home has not yet been tested, you should have the house tested.
If you are having a new home built, there are features that can be incorporated into your home during construction to reduce radon levels.
These radon testing guidelines have been developed specifically to deal with the time-sensitive nature of home purchases and sales, and the potential for radon device interference.  These guidelines are slightly different from the guidelines in other EPA publications which provide radon testing and reduction information for non-real estate situations.
This guide recommends three short-term testing options for real estate transactions.  The EPA also recommends testing a home in the lowest level which is currently suitable for occupancy, since a buyer may choose to live in a lower area of the home than that used by the seller.
1. Why do you need to test for radon?
a. Radon has been found in homes all over the U.S.
Radon is a radioactive gas that has been found in homes all over the United States. It comes from the natural breakdown of uranium in soil, rock and water, and gets into the air you breathe. Radon typically moves up through the ground to the air above, and into your home through cracks and other holes in the foundation. Radon can also enter your home through well water. Your home can trap radon inside.
Any home can have a radon problem, including new and old homes, well-sealed and drafty homes, and homes with or without basements. In fact, you and your family are most likely to get your greatest radiation exposure at home. That is where you spend most of your time.
Nearly one out of every 15 homes in the United States is estimated to have an elevated radon level (4 pCi/L or more).  Elevated levels of radon gas have been found in homes in your state. 
b. The EPA and the Surgeon General recommend that you test your home.
Testing is the only way to know if you and your family are at risk from radon. The EPA and the Surgeon General recommend testing all homes below the third floor for radon.
You cannot predict radon levels based on state, local, or neighborhood radon measurements.  Do not rely on radon test results taken in other homes in the neighborhood to estimate the radon level in your home.  Homes which are next to each other can have different radon levels.  Testing is the only way to find out what your home's radon level is.
In some areas, companies may offer different types of radon service agreements.  Some agreements let you pay a one-time fee that covers both testing and radon mitigation, if needed.  



U.S. Surgeon General's
Health Advisory
"Indoor radon gas is the second-leading cause of lung cancer in the United States, and breathing it over prolonged periods can present a significant health risk to families all over the country.  It's important to know that this threat is completely preventable.  Radon can be detected with a simple test, and fixed through well-established venting techniques." 
 January 2005 
2. I'm selling a home.  What should I do? 
a. If your home has already been tested for radon...
If you are thinking of selling your home and you have already tested your home for radon, review the Radon Testing Checklist to make sure that the test was done correctly.  If so, provide your test results to the buyer.
No matter what kind of test you took, a potential buyer may ask for a new test, especially if:
the Radon Testing Checklist items were not met;
the last test is not recent, (e.g., within two years);
you have renovated or altered your home since you tested; or
the buyer plans to live in a lower level of the house than was tested, such as a basement suitable for occupancy but not currently lived in.
A buyer may also ask for a new test if your state or local government requires disclosure of radon information to buyers.
b. If your home has not yet been tested for radon...
Have a test taken as soon as possible. If you can, test your home before putting it on the market.  You should test in the lowest level of the home which is suitable for occupancy. This means testing in the lowest level that you currently live in or a lower level not currently used, but which a buyer could use for living space without renovations. 
The radon test result is important information about your home's radon level.  Some states require radon measurement testers to follow a specific testing protocol.  If you do the test yourself, you should carefully follow the testing protocol for your area or the EPA's Radon Testing Checklist.  If you hire a contractor to test your residence, protect yourself by hiring a qualified individual or company.
You can determine a service provider's qualifications to perform radon measurements or to mitigate your home in several ways.  Many states require radon professionals to be licensed, certified or registered.  Most states can provide you with a list of knowledgeable radon service providers doing business in your state.  In states that don't regulate radon services, ask the contractor if they hold a professional proficiency or certification credential. Such programs usually provide members with a photo-ID card which indicates their qualification(s) and its expiration date.  If in doubt, you should check with their credentialing organization.  Alternatively, ask the contractor if they've successfully completed formal training appropriate for testing or mitigation, e.g., a course in radon measurement or radon mitigation. 
3. I'm buying a home.  What should I do?

a. If the home has already been tested for radon...
If you are thinking of buying a home, you may decide to accept an earlier test result from the seller, or ask the seller for a new test to be conducted by a qualified radon tester.  Before you accept the seller's test, you should determine the results of previous testing by finding out:
who conducted the previous test (the homeowner, a radon professional, or some other person);
where in the home the previous test was taken, especially if you may plan to live in a lower level of the home.  For example, the test may have been taken on the first floor.  However, if you want to use the basement as living space, test there, too;
what, if any, structural changes, alterations, or changes in the heating, ventilation, and air conditioning (HVAC) system have been made to the house since the test was done.  Such changes may affect radon levels.
If you accept the seller's test, make sure that the test followed the Radon Testing Checklist.  
If you decide that a new test is needed, discuss it with the seller as soon as possible. 
b. If the home has not yet been tested for radon...
Make sure that a radon test is done as soon as possible. Consider including provisions in the contract specifying:
where the test will be located;
who should conduct the test;
what type of test to do;
when to do the test;
how the seller and the buyer will share the test results and test costs (if necessary); and
when radon mitigation measures will be taken, and who will pay for them.

Make sure that the test is done in the lowest level of the home suitable for occupancy. This means the lowest level that you are going to use as living space which is finished or does not require renovations prior to use. A state or local radon official or qualified radon tester can help you make some of these decisions. If you decide to finish or renovate an unfinished area of the home in the future, a radon test should be taken before starting the project, and after the project is finished. Generally, it is less expensive to install a radon-reduction system before (or during) renovations rather than afterward.
4. I'm buying or building a new home.  How can I protect my family?
a. Why should I buy a radon-resistant home?
Radon-resistant techniques work.  When installed properly and completely, these simple and inexpensive passive techniques can help to reduce radon levels.  In addition, installing them at the time of construction makes it easier to reduce radon levels further if the passive techniques don't reduce radon levels below 4 pCi/L.  Radon-resistant techniques may also help to lower moisture levels and those of other soil-gases.  Radon-resistant techniques:
make upgrading easy:  Even if built to be radon-resistant, every new home should be tested for radon after occupancy.  If you have a test result of 4 pCi/L or more, a vent fan can easily be added to the passive system to make it an active system, and further reduce radon levels.

are cost-effective:  Building radon-resistant features into the house during construction is easier and cheaper than fixing a radon problem from scratch later.  Let your builder know that radon-resistant features are easy to install using common building materials.

save money:  When installed properly and completely, radon-resistant techniques can also make your home more energy-efficient and help you save on your energy costs.
In a new home, the cost to install passive radon-resistant features during construction is usually between $350 to $500.  In some areas, the cost may be as low as $100.  A qualified mitigator will charge about $300 to add a vent fan to a passive system, making it an active system and further reducing radon levels.  In an existing home, it usually costs between $800 to $2,500 to install a radon mitigation system.
b. What are radon-resistant features?
Radon-resistant features may vary for different foundations and site requirements.  If you're having a house built, you can learn about the EPA's Model Standards (and architectural drawings) and explain the techniques to your builder.  If your new house was built (or will be built) to be radon-resistant, it will include these basic elements:

1. gas-permeable layer:  This layer is placed beneath the slab or flooring system to allow the soil gas to move freely underneath the house.  In many cases, the material used is a 4-inch layer of clean gravel.  This gas-permeable layer is used only in homes with basement and slab-on-grade foundations; it is not used in homes with crawlspace foundations. 
   
   
2. plastic sheeting:  Plastic sheeting is placed on top of the gas-permeable layer and under the slab to help prevent the soil gas from entering the home.  In crawlspaces, the sheeting (with seams sealed) is placed directly over the crawlspace floor. 
   
   
3. sealing and caulking:  All below-grade openings in the foundation and walls are sealed to reduce soil-gas entry into the home. 
   
   
4. vent pipe:  A 3- or 4-inch PVC pipe (or other gas-tight pipe) runs from the gas-permeable layer through the house to the roof to safely vent radon and other soil gases to the outside. 
   
   
5. junction boxes:  An electrical junction box is included in the attic to make the wiring and installation of a vent fan easier, if, for example, you decide to activate the passive system if your test results show an elevated radon level (4 pCi/L or more).  A separate junction box is placed in the living space to power the vent-fan alarm.  An alarm is installed along with the vent fan to indicate when the vent fan is not operating properly.

5. How can I get reliable radon test results?
Radon testing is easy and the only way to find out if you have a radon problem in your home.
a. Types of Radon Devices
Since you cannot see or smell radon, special equipment is needed to detect it.  When you're ready to test your home, you can order a radon test kit by mail from a qualified radon measurement service provider or laboratory.  You can also hire a qualified radon tester, very often a home inspector, who will use the radon device(s) suitable to your situation. If you hire a home inspector, make sure you hire a qualified InterNACHI member -- specifically, an IAC2 certified air-quality professional.  The most common types of radon testing devices are listed below.  
Passive Devices
Passive radon-testing devices do not need power to function.  These include charcoal canisters, alpha-track detectors, charcoal liquid scintillation devices, and electret ion chamber detectors, which are available in hardware, drugstores, and other stores; they can also be ordered by mail or phone.  These devices are exposed to the air in the home for a specified period of time, and then sent to a laboratory for analysis.  Both short-term and long-term passive devices are generally inexpensive. Some of these devices may have features that offer more resistance to test interference or disturbance than other passive devices. Qualified radon testers may use any of these devices to measure the home's radon level.
Active Devices
Active radon-testing devices require power to function. These include continuous radon monitors and continuous working-level monitors.  They continuously measure and record the amount of radon and its decay products in the air.  Many of these devices provide a report of this information, which can reveal any unusual or abnormal swings in the radon level during the test period. A qualified tester can explain this report to you.  In addition, some of these devices are specifically designed to deter and detect test interference. Some technically advanced active devices offer anti-interference features.  Although these tests may cost more, they may ensure a more reliable result.
b. General Information for All Devices
A state or local radon official can explain the differences between devices, and recommend the ones which are most appropriate for your needs and expected testing conditions.
Make sure to use a radon measurement device from a qualified laboratory.  Certain precautions should be followed to avoid interference during the test period.  See the Radon Testing Checklist for more information on how to get a reliable test result.
Radon Test Device Placement
The EPA recommends that testing device(s) be placed in the lowest level of the home suitable for occupancy. This means testing in the lowest level (such as a basement) which a buyer could use for living space without renovations. The test should be conducted in a room to be used regularly (such as a family room, living room, play room, den or bedroom); do not test in a kitchen, bathroom, laundry room or hallway.  Usually, the buyer decides where to locate the radon test, based on their expected use of the home.  A buyer and seller should explicitly discuss and agree on the test location to avoid any misunderstanding.  Their decision should be clearly communicated to the person performing the test.
c. Preventing or Detecting Test Interference
There is a potential for test interference in real estate transactions. There are several ways to prevent or detect test interference:
Use a test device that frequently records radon or decay-product levels to detect unusual swings.
Employ a motion detector to determine whether the test device has been moved or if testing conditions have changed.
Use a proximity detector to reveal the presence of people in the room, which may correlate to possible changes in radon levels during the test.
Record the barometric pressure to identify weather conditions which may have affected the test.
Record the temperature to help assess whether doors and windows have been opened during the test. 
Apply tamper-proof seals to windows to ensure closed-house conditions.
Have the seller/occupant sign a non-interference agreement.
Home buyers and sellers should consult a qualified radon test provider about the use of these precautions.
d. Length of Time to Test
There are two general ways to test your home for radon:
Because radon levels vary from day to day and from season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level.  However, if you need results quickly, a short-term test may be used to decide whether to fix the home.
Short-Term Testing:
The quickest way to test is with short-term tests. Short-term tests remain in your home from two days to 90 days, depending on the device. There are two groups of devices which are more commonly used for short-term testing. The passive-device group includes alpha-track detectors, charcoal canisters, charcoal liquid scintillation detectors, and electret ion chambers. The active device group consists of different types of continuous monitors.
Whether you test for radon yourself, or hire a state-certified tester or a privately certified tester, all radon tests should be taken for a minimum of 48 hours. A longer period of testing is required for some devices.
Long-Term Testing
Long-term tests remain in your home for more than 90 days. Alpha-track andelectret ion chamber detectors are commonly used for this type of testing. A long-term test will give you a reading that is more likely to tell you your home's year-round average radon level than a short-term test. If time permits, long-term tests (more than 90 days) can be used to confirm initial short-term results. When long-term test results are 4 pCi/L or higher, the EPA recommends mitigating the home.
e. Doing a Short-Term Test...
If you are testing in a real estate transaction and you need results quickly, any of the following three options for short-term tests are acceptable in determining whether the home should be fixed. Any real estate test for radon should include steps to prevent or detect interference with the testing device.
When Choosing a Short-Term Testing Option...
There are trade-offs among the short-term testing options.  Two tests taken at the same time (simultaneous) would improve the precision of this radon test.  One test followed by another test (sequential) would most likely give a better representation of the seasonal average.  Both active and passive devices may have features which help to prevent test interference.  Your state radon office can help you decide which option is best.
Short-Term Testing Options
What to Do Next

Passive: 
Take two short-term tests at the same time in the same location for at least 48 hours.  
or 
Take an initial short-term test for at least 48 hours.  Immediately upon completing the first test, do a second test using an identical device in the same location as the first test.

Fix the home if the average of two tests is 4 pCi/L or more.
Fix the home if the average of the two tests is 4 pCi/L or more.

Active: 
Test the home with a continuous monitor for at least 48 hours.

Fix the home if the average radon level is 4 pCi/L or more.
f.  Using testing devices properly for reliable results.
If you do the test yourself:
When you are taking a short-term test, close windows and doors and keep them closed, except for normal entry and exit.  If you are taking a short-term test lasting less than four days, be sure to:
Close your windows and outside doors at least 12 hours before beginning the test.
Do not conduct short-term tests lasting less than four days during severe storms or periods of high winds.
Follow the testing instructions and record the start time and date.
Place the test device at least 20 inches above the floor in a location where it will not be disturbed and where it will be away from drafts, high heat, high humidity, and exterior walls.
Leave the test kit in place for as long as the test instructions say.
Once you have finished the test, record the stop time and date, re-seal the package, and return it immediately to the lab specified on the package for analysis.
You should receive your test results within a few weeks. If you need results quickly, you should find out how long results will take and, if necessary, request expedited service.
If you hire a qualified radon tester:
In many cases, home buyers and sellers may decide to have the radon test done by a qualified radon tester who knows the proper conditions, test devices, and guidelines for obtaining a reliable radon test result.  They can also:

• evaluate the home and recommend a testing approach designed to make sure you get reliable results;
• explain how proper conditions can be maintained during the radon test;
• emphasize to occupants of a home that a reliable test result depends on their cooperation.  Interference with, or disturbance of, the test or closed-house conditions will invalidate the test result;
• analyze the data and report measurement results; and
• provide an independent test.

g. Interpreting Radon Test Results
The average indoor radon level is estimated to be about 1.3 pCi/L; roughly 0.4 pCi/L of radon is normally found in the outside air. The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. While this goal is not yet technologically achievable for all homes, radon levels in many homes can be reduced to 2 pCi/L or below.
Radon Test Results Reported in Two Ways
Your radon test results may be reported in either picoCuries per liter of air (pCi/L) or working levels (WL). If your test result is in pCi/L, the EPA recommends you fix your home if your radon level is 4 pCi/L or higher. If the test result is in WL, the EPA recommends you fix the home if the working level is 0.02 WL or higher.  Some states require WL results to be converted to pCi/L to minimize confusion.
Sometimes, short-term tests are less definitive about whether the home is at or above 4 pCi/L, particularly when the results are close to 4 pCi/L. For example, if the average of two short-term tests is 4.1 pCi/L, there is about a 50% chance that the year-round average is somewhat below 4 pCi/L. 
However, the EPA believes that any radon exposure carries some risk; no level of radon is safe. Even radon levels below 4 pCi/L pose some risk.  You can reduce your risk of lung cancer by lowering your radon level.
As with  other environmental pollutants, there is some uncertainty about the magnitude of radon health risks. However, we know more about radon risks than risks from most other cancer-causing substances. This is because estimates of radon risks are based on data from human studies on underground miners. Additional studies on more typical populations are underway.
Your radon measurement will give you an idea of your risk of getting lung cancer from radon. Your chances of getting lung cancer from radon depend mostly on:

• your home's radon level; 
• the amount of time you spend in your home; and
• whether you are a smoker or have ever smoked.

Smoking combined with radon is an especially serious health risk. If you smoke or are a former smoker, the presence of radon greatly increases your risk of lung cancer. If you stop smoking now and lower the radon level in your house, you will reduce your lung cancer risk.
Based on information contained in the National Academy of Sciences' 1998 report, The Health Effects of Exposure to Indoor Radon, your radon risk may be somewhat higher than shown, especially if you have never smoked.  It's never too late to reduce your risk to lung cancer.  Don't wait to test and fix a radon problem.  If you are a smoker, stop smoking.
Go to the Radon Risk Comparison Charts
Radon Testing Checklist
For reliable test results, follow this Radon Testing Checklist carefully.  Testing for radon is not complicated.  Improper testing may yield inaccurate results and require another test.  Disturbing or interfering with the test device or with closed-house conditions may invalidate the test results, and is actually illegal in some states.  If the seller or qualified tester cannot confirm that all items have been completed, take another test.
Before conducting a radon test:
Notify the occupants of the importance of proper testing conditions. Give the occupants written instructions or a copy of this Guide and explain the directions carefully.
Conduct the radon test for a minimum of 48 hours; some test devices have a minimum exposure time greater than 48 hours.
When doing a short-term test ranging from two to four days, it is important to maintain closed-house conditions for at least 12 hours before the beginning of the test and during the entire test period.
When doing a short-term test ranging from four to seven days, the EPA recommends that closed-house conditions be maintained.
If you conduct the test yourself, use a qualified radon measurement device and follow the laboratory's instructions.  Your state may be able to provide you with a list of do-it-yourself test devices available from qualified laboratories.
If you hire someone to do the test, hire only a qualified individual.  Some states issue photo identification (ID) cards; ask to see it.  The tester's ID number, if available, should be included or noted in the test report.
The test should include method(s) to prevent or detect interference with testing conditions, or with the testing device itself.
If the house has an active radon-reduction system, make sure the vent fan is operating properly.  If the fan is not operating properly, have it (or ask to have it) repaired and then test it.
"Closed-house conditions" mean keeping all windows closed, keeping doors closed except for normal entry and exit, and not operating fans or other machines which bring in air from outside.  Fans that are part of a radon-reduction system or small exhaust fans operating for only short periods of time may run during the test.
During a radon test:
Maintain closed-house conditions during the entire time of a short-term test, especially for tests shorter than one week.
Operate the home's heating and cooling systems normally during the test. For tests lasting less than one week, operate only air-conditioning units which re-circulate interior air.
Do not disturb the test device at any time during the test.
If a radon-reduction system is in place, make sure the system is working properly and will be in operation during the entire radon test.
After a radon test:
If you conduct the test yourself, be sure to promptly return the test device to the laboratory.  Be sure to complete the required information, including start and stop times, test location, etc.
If an elevated level is found, fix the home. Contact a qualified radon-reduction contractor about lowering the radon level.  The EPA recommends that you fix the home when the radon level is 4 pCi/L or more.
Be sure that you or the radon tester can demonstrate or provide information to ensure that the testing conditions were not violated during the testing period.


6. What should I do if the radon level is high?
a. High radon levels can be reduced.
The EPA recommends that you take action to reduce your home's indoor radon levels if your radon test result is 4 pCi/L or higher. It is better to correct a radon problem before placing your home on the market because then you will have more time to address a radon problem. 
If elevated levels are found during the real estate transaction, the buyer and seller should discuss the timing and costs of the radon reduction.  The cost of making repairs to reduce radon levels depends on how your home was built and other factors. Most homes can be fixed for about the same cost as other common home repairs, such as painting or having a new hot water heater installed. The average cost for a contractor to lower radon levels in a home can range from $800 to about $2,500.
b. How to Lower The Radon Level in Your Home
A variety of methods can be used to reduce radon in homes. Sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction. The EPA does not recommend the use of sealing alone to limit radon entry.  Sealing alone has not been shown to lower radon levels significantly or consistently. 
 In most cases, a system with a vent pipe and fan is used to reduce radon.  These "sub-slab depressurization" systems do not require major changes to your home. Similar systems can also be installed in homes with crawlspaces.  These systems prevent radon gas from entering the home from below the concrete floor and from outside the foundation.  Radon mitigation contractors may use other methods that may also work in your home. The right system depends on the design of your home and other factors. 
Radon and Home Renovations
 If you are planning any major renovations, such as converting an unfinished basement area into living space, it is especially important to test the area for radon before you begin.
If your test results indicate an elevated radon level, radon-resistant techniques can be inexpensively included as part of the renovation. Major renovations can change the level of radon in any home.  Test again after the work is completed.
You should also test your home again after it is fixed to be sure that radon levels have been reduced. If your living patterns change and you begin occupying a lower level of your home (such as a basement) you should re-test your home on that level. In addition, it is a good idea to re-test your home sometime in the future to be sure radon levels remain low.
c. Selecting a Radon-Reduction (Mitigation) Contractor
Select a qualified radon-reduction contractor to reduce the radon levels in your home.  Any mitigation measures taken or system installed in your home must conform to your state's regulations.  
The EPA recommends that the mitigation contractor review the radon measurement results before beginning any radon-reduction work.  Test again after the radon mitigation work has been completed to confirm that previous elevated levels have been reduced.  
d. What can a qualified radon-reduction contractor do for you?
A qualified radon-reduction (mitigation) contractor should be able to:

• review testing guidelines and measurement results, and determine if additional measurements are needed; 
• evaluate the radon problem, and provide you with a detailed, written proposal on how radon levels will be lowered; 
• design a radon-reduction system; 
• install the system according to EPA standards, or state or local codes; and
• make sure the finished system effectively reduces radon levels to acceptable levels.

Choose a radon-mitigation contractor to fix your radon problem just as you would for any other home repair.  You may want to get more than one estimate.  Ask for and check their references.  Make sure the person you hire is qualified to install a mitigation system.  Some states regulate or certify radon-mitigation services providers.
Be aware that a potential conflict of interest exists if the same person or firm performs the testing and installs the mitigation system.  Some states may require the homeowner to sign a waiver, in such cases. Contact your state radon office for more information.
e. Radon in Water
The radon in your home's indoor air can come from two sources:  the soil and your water supply.  Compared to radon entering your home through water, radon entering your home through soil is a much larger risk.  If you've tested for radon in air and have elevated radon levels, and your water comes from a private well, have your water tested.  The devices and procedures for testing your home's water supply are different from those used for measuring radon in air.
The radon in your water supply poses an inhalation risk and an ingestion risk.  Research has shown that your risk of lung cancer from breathing radon in the air is much larger than your risk of stomach cancer from swallowing water with radon in it.  Most of your risk from radon in water comes from radon released into the air when water is used for showering and other household purposes.
Radon in your home's water is not usually a problem when its source is surface water.  Radon in water is more likely when its source is ground water, e.g., a private well or a public water supply system that uses ground water.  Some public water systems treat their water to reduce radon levels before it is delivered to your home.  If you are concerned that radon may be entering your home through the water, and your water comes from a public water supply, contact your water supplier.
If you've tested your private well and have radon in your water supply, it can be treated in one of two ways.  Point-of-entry treatment can effectively remove radon from the water before it enters your home.  Point-of-entry treatment usually employs either granular activated-carbon (GAC) filters, or aeration devices.  While GAC filters usually cost less than aeration devices, filters can collect radioactivity and may require a special method of disposal.  Point-of-use treatment devices remove radon from your water at the tap, but only treat a small portion of the water you use, e.g., the water you drink.  Point-of-use devices are not effective in reducing the risk of breathing radon released into the air from all water used in the home.
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