Heat, energy and insulation are all related to each other. As inspectors we should understand how heat moves around inside a home, and how insulation can control that movement. One main reason to understand how heat moves is because warm air can carry moisture, and warm moist air needs to be controlled in relation to a building envelope. Uncontrolled, moving warm air and moisture can cause lots of problems. Another reason to learn about heat is that insulation provides a resistance to the flow of heat, and the more insulation there is, the less energy is needed to heat and cool the house.

Heat needs to be controlled to keep the occupants of the home comfortable. When a home is well insulated, your client will save on energy costs. After learning the information in the next few sections about heat, moisture, air, and insulation, you’ll be able to perform a great inspection, and speak to your client about how the building envelope is functioning.

Now, let’s talk heat. There are essentially three ways that heat moves from one area to another. When bodies of unequal temperatures are near each other, heat leaves one body and goes to the other. Heat moves from the hotter body, and the colder body absorbs it. The greater the difference in temperature, the greater the rate of flow of the heat.

Heat moves from one body to another by the following ways:

· Radiation;

· Conduction; and

· Convection.

Radiation

Radiation is the transfer of heat energy by electromagnetic wave motion. Heat is transferred in direct rays. It travels in a straight line from the source to the body. The closer you are to the hot object, the warmer you feel. The intensity of the heat radiated from the object decreases as the distance from the object increases.

You feel cool in a room that has a cold floor, walls and ceiling. The amount of heat loss from your body in that room depends upon the relative temperature of the objects in that room. The colder the floor is (relative to the temperature of your feet), the great the heat loss from your body will be standing there. If the floor, walls and ceiling of that room are relatively warmer than your body temperature, then heat will be radiated to your body from those objects or surfaces.

When you step into a cold room, you can immediately feel the heat energy leaving your body. Use all of your senses as an inspector when moving about the house. Just entering a space with your body can tell you a lot of information about that space, the insulation, the heat, air movement, and even moisture or humidity levels. Some inspectors can give a good estimate on the temperature of an attic space simply by entering it. Keep aware of your surroundings when moving about the interior of the house.

Radiant heat emits in all directions. Radiant heating in residential buildings include piping and electrical wiring in floors, walls and ceilings. Reflective materials are commonly used in a radiant heat emitting system in order to direct or control where the heat is emitted.

Radiation happens when heat moves as energy waves, called infrared waves, directly from its source to something else. This is how the heat from the Sun gets to Earth. In fact, all hot things radiate heat to cooler things. When the heat waves hit the cooler thing, they make the molecules of the cooler object speed up. When the molecules of that object speed up, the object becomes hotter.

Conduction

Conduction is the transfer of heat from one molecule to another, or through one substance to another. It is heat that moves from one body to another by direct contact. For example, heat is transferred by conduction from a boiler heat exchanger to the water passing through it. When you touch a suction lines of an air conditioner and it feels warm, that’s heat energy moving from the warm copper pipe to your cooler hand – by conduction.

Heat is a form of energy, and when that heat comes into contact with matter, it makes the atoms and molecules move. When atoms or molecules move, they collide with other atoms or molecules and make them move too. This movement transfers heat through matter.

This is demonstrated when touching a ceramic coffee cup. The exterior surface of the cup is warm to the touch because the heat of the hot coffee transferred through the cup material.

Convection

Convection is known by most people by the using the phrase “Heat rises.” Convection is the transfer of heat by warming the air next to a hot surface and then moving that warm air. It’s the transfer of heat by the motion of the heated matter itself. The air moves from one place to another, carrying heat along with it. Since warm air is lighter than the cool air around it, the warm air (or heat) rises.

Warm fluids tend to rise while the surrounding cool fluids fall. This rising and falling tends to form loops or convective loops, where warm air, for example rises and cool air falls. Early warm-air furnaces, gravity furnaces, used principles of convective loops. In a gravity system the warm air rises and cool air falls, and this is how the gravity warm-air heating system circulated air.

When a certain amount of air is heated up, it expands and takes up more space.  In other words, hot air is less dense than cold air.  Any substance that is less dense than the fluid (gas or liquid) of its surroundings will float.  Hot air floats on cold air because it is less dense, just as a piece of wood floats because it is less dense than water.  Warm air is often described as weighing less than cool air. Warm air rises, and cool air falls. The weight per unit volume of air decreases as its temperature increases. And conversely, the weight per unit volume of air increases as its temperature decreases.

Inside a wall cavity, there can be convective loops, where cool and warm air are moving about inside the wall cavity. If warm, moist air comes in contact with a cold surface of that wall assembly, then condensation may form inside the wall. And that’s not good.

For another example, an old gravity furnace heats the air; the air gets lighter and rises out of the heating system. Cool air enters the heating system and pushes or displaces the warm, rising air. The warm air rises up through warm-air ducts or pipes (often called stacks) that are inside the walls. The warm air rises up through the building. The warm air enters a room through the supply registers on the wall or floor. The cool air falls out of the room and might return through a return grille, and travel back through return ducts to the heating system.

Some houses with old gravity heating systems may not have a lot of ducts and pipes, but might rely on large openings (covered with iron grates or grilles) in the floors that allow the cool air to fall down through the building. The cool air is allowed to simply fall back to the furnace – hence the name gravity warm-air heating system.

The air circulation in a house with a gravity warm-air heating system will depend upon the temperature difference between the warm air rising and the cool air falling. The greater the difference, the greater the speed of the air circulating.

Summary

So, heat moves from one body to another by the following three ways:

· Radiation;

· Conduction; and

· Convection.

Understanding how heat moves will help you understand how moisture moves too.  You can find information about how to inspect for moisture and other subjects at http://www.bengromicko.com.

Water is sometimes called “hard” because it has a high mineral content when compared with ordinary or “soft” water. There are some things that you should know about hard water – first of all, it is not considered to be dangerous. In fact, hard water contributes to nutritional requirements for many people, although it doesn’t always taste good. Inspectors should be familiar with hard water because it can also cause plumbing fixtures and pipes to clog up and fail prematurely and reduce the overall efficiency of the plumbing system. It also has the potential to make household chores such as dish washing, clothes washing and bathing more cumbersome. To find out more about hard water effects and ways to soften it, check out our new article on hard water.

InterNACHI just released a new course on inspecting the attic, insulation, and interior of a residential property. The course, which includes over 40,000 words, a plethora of helpful diagrams and pictures, quizzes and a final exam, is accredited, state approved and totally free for InterNACHI members. Topics include radiant barriers, ventilation, clearance, ice dams, heat movement, attic access and much, much more. Take the course or read more about it. Enjoy!

When admired from afar or in the wild, birds are beautiful, elegant creatures. When they roost on buildings in large numbers, however, they can cause serious problems. Bird droppings can corrode building materials, transmit disease and create an unsightly mess. Commercial property owners, in particular, can be endangered by pest birds because they can damage company image and create huge liability concerns if an employee or customer slips and falls on droppings. In fact, one man received a $2,700,000 settlement from the property owner when he injured himself after slipping on bird droppings. To find out more about the issue, read our new article on pest birds.

InterNACHI is pleased to announce that the State of Nevada, Department of Business and Industry, Real Estate Division approved InterNACHI’s free, online courses for home inspector continuing education purposes.

The free, online inspection courses include such topics as: commercial property inspections, structural issues, roofing inspections, plumbing inspections, log home inspections, green building, electrical inspections, safety practices for home inspectors, means of egress, and thermal imaging.

The Nevada Department of Agriculture also approved InterNACHI’s free, online Wood Destroying Organism course.

InterNACHI is the largest inspection school in Nevada and the world and has been awarded hundreds of government approvals and accreditations.

CLICK HERE to see actual home inspection continuing education approval certificates from Nevada.

Formaldehyde is a carcinogenic compound that will accumulate in indoor environments under the right conditions. It can be found in building materials that contain glue, such as OSB, or created by combustion appliances. To find out about other sources of this chemical and learn how dangerous it is, check out our new article on formaldehyde.

Fire alarm systems can easily degrade over time due to contact with airborne pollutants or electronic malfunctions. Although not required to inspect these systems, inspectors should understand the basic ways in which fire alarm systems are inspected and maintained. Inspectors can inform their clients about routine maintenance and required periodic inspections, which should be performed by qualified professionals. Check out our new article to find out more.

Moisture can enter a home in many different ways, such as through plumbing leaks, floods, air infiltration or diffusion through building material. Inspectors should know these points of moisture intrusion so they waste little time searching for evidence of moisture damage in homes. For more information, take a look at our new article on the subject of moisture intrusion.

Inspectors looking to buy a vehicle for their business have a lot of things to consider. Will this vehicle be used mainly for business, or will it double as the primary vehicle for the owner and possibly the family, too? Will a GPS navigation unit help you find the houses of your clients? Find out more about vehicle considerations in our new article on inspector vehicles.

Composting is a great way to reduce the size of landfills and turn food waste into a useful product, but little gets said about the ways in which composting can be dangerous. Did you know that compost piles are very flammable and under the right conditions they can spontaneously combust? Some fires in commercial composting facilities have even tied up multiple fire departments. Compost can also contain numerous pathogens that can cause people all kinds of diseases, such as histoplasmosis or potentially deadly infections. To see more on the subject, check out our new article on composting hazards.

Unless you’re already an expert in the subject, you’re probably not adequately familiar with real estate terminology to make intelligent decisions regarding ownership and leasing commercial property. Do you know what a build-out is or how an appraisal is performed? You should know the different kinds of leases that are available, such as flat leases, percentages leases and net leases. All of this and more are covered in InterNACHI’s new article on commercial real estate terms every inspector should know.

So you’ve decided to move your inspection business out of your house and into a commercial space. Should you buy or should you rent? Neither option is inherently better than the other, and both have their own headaches and responsibilities. You should consider your business and your finances closely before you make this kind of decision. Specifically, would having a landlord place too much of a limitation on your business’s ability to modify with changing needs? Is ownership a good investment? If buying the property requires you yourself to become a landlord, are you ready for this responsibility? Take a look at our new article on buying vs. renting commercial property to get a better understanding of the difference between these two options.

If you’re moving your inspection business into a commercial space and you’ve never owned or rented commercial space before, you’re going to be surprised just how much is involved in maintaining the store’s appearance, heating, cooling, utilities and general functionality. Have you considered what kind of office equipment you’re going to need, and do you know how to negotiate long-term service contracts on that equipment? Do you know where to shop for bathroom supplies? Did you think about having a private area in which you may speak confidentially on the phone, or change clothes after a particularly dirty inspection? Check out our commercial office checklist to find out about theses issues and more.

Loans are very important for small businesses, and inspectors are no exception. Whether you need the money to fund a move from your house and into a commercial space, or to resolve a cash flow problem, the way you approach a loan attempt will determine whether you get the loan you want. An experienced lawyer will know what documentation you need while the Small Business Administration can help you navigate unfamiliar waters. Have a plan for how you spend the money so the loan agency knows you are responsible enough to pay it back. In our new article on the mistakes that inspectors make while shopping for a commercial loan, we explain these things and more.

If you don’t live in areas where sinkholes are common, such as Florida, you might have never even considered them during inspections. But so many things can cause the ground to cave in that you really should be aware of the warning signs. Even an old septic tank that the client never knew existed could cave in, taking with it the earth above and whoever is standing there. More people have died in this way than you probably are aware. To read about how sinkholes form and the warning signs to look for, check out our new article.