Fireplaces are aesthetically appealing to many people. Because of nostalgia, or for reasons of intuitive common sense, homeowners have for years been demanding open fireplaces in their homes. Estimates indicate that over half the single family homes in the U.S. have at least one fireplace and about one million new fireplaces are being installed annually. Home buyers express an overwhelming preference for built-in fireplaces and a brisk business is being done in prefabricated units.  

Where wood fuel is plentiful and inexpensive, people are turning down central heating system thermostats, stoking up fireplaces and learning through personal experience the pros and cons of heating with wood.

A fireplace must generally be considered a luxury, since its primary value is enhancing the appearance and atmosphere of a room. Fireplaces are basically low-efficiency home heating units (only about 10% efficient) unless extensive modifications are made in their design and/or operation to reduce the amount of heat lost up the chimney. Heating efficiency is net amount of usable heat generated from total fuel burned. Heat output is simply total amount of heat produced from fuel consumed. Several facts should be evaluated and some accessory heat-intensification devices considered if energy economics is a factor in justifying a home fireplace. By so doing many families have been able to set thermostats 10 deg. to 15 deg. F lower than normal and are enjoying the combined benefits of reduced central system heating costs and open fireplaces with acceptable efficiencies.

Fireplace Heat Distribution and Efficiency Heat, by laws of physics, is transferred by three methods--convection, radiation and conduction. Convection is transferring of heat from one area to another by moving air. Radiation is movement of infrared electromagnetic rays through air with virtually no warming of the air but warming of any objects when the rays strike them. Sunlight is an example of radiant heat. Conduction is transfer of heat along a solid object -- placing a warm hand on a cold block of ice conducts heat from the hand to the ice mass.

Fireplace heat from burning wood is about 20% radiant and 80% hot gases. In actual operation, most of the effective heat from an open fireplace is radiant heat. About 90% of the heat output goes up the chimney and is discharged to the outdoors, accounting for even the well-designed and constructed fireplace being only about 10% efficient as a home heating unit. Under many conditions, a roaring fireplace can actually remove more heat from a home than it discharges into the room.

Wood combustion is a three-stage process. First moisture is evaporated and driven off; second, volatile matter begins to vaporize into gases at temperatures above 500 deg. F; and third, gases and charcoal are burned at temperatures above 1100 deg. F.

To burn wood efficiently, the fire must be maintained at a high enough temperature to burn all the combustible materials of the wood. The amount of radiation from a fireplace varies depending on type of fuel used, intensity and size of fire and burning temperature of fire, which can range from as low as 500 F to well above 1100 F. Masonry brick linings in fireplaces radiate heat back to the fire to help create the higher temperature fires necessary for optimum combustion.

The greatest heat loss from a conventional open fireplace is through the damper. The damper consists of a cast-iron frame with a hinged lid to open or close the throat opening above the fireplace. It is important that the full damper opening area be equal to or greater than the flue area in size. Dampers are not always installed in fireplaces but are definitely recommended.

A well-designed, properly-installed damper will:

• allow regulation of the draft
• permit adjustment of the throat opening according to the type of fire and draft to reduce heat loss up the chimney
• close off flue to prevent heat loss from living area when the fireplace is not being used
• close off the chimney in summer to prevent insects, birds or bats from entering the house through the chimney.
• Close attention should be given to damper positioning in order to minimize the loss of heat up the chimney. Generally, it should be opened just enough to prevent fireplace from smoking, and no more.

Outside Air Inlet

Wood requires large quantities of "makeup" air for proper combustion. This means a properly-operating fireplace will draw from 200 to 600 or more cubic feet of air per minute up the chimney. Unless special inlets provide outdoor air to satisfy this makeup requirement, combustion air for a fireplace is drawn from warm air inside the house. Cold outdoor air must infiltrate into the house to replace warm air being used to support the fireplace fire. A normal fire requiring 400 cubic feet of air per minute will draw the equivalent of all the air in a 15- by 20-foot room in about six minutes.

CAUTION--With today's tightly-constructed houses incorporating weather stripped doors, caulked windows and self-closing exhaust vents, it is possible for a fireplace to set up a reverse draft and suck poisonous carbon monoxide fumes from combustion-type water heaters or furnaces and discharge them into the living area. Also, in tight homes, the furnace may consume enough oxygen from the air in the house to cause problems to occupants. To be safe, a positive source of outside air should be supplied to all fireplaces and wood- or coal-burning stoves. This can be provided by installing an outside air vent or opening a window when the fireplace is being used.

Dust mites are tiny animals you cannot see. Every home has dust mites. They feed on skin flakes and are found in mattresses, pillows, carpets, upholstered furniture, bedcovers, clothes, stuffed toys, and fabric or other fabric-covered items. Body parts and feces of dust mites can trigger asthma in sensitive individuals.

Maintain low indoor humidity ideally between 30-50% relative humidity. Humidity levels can be measured by hygrometers which are available at local hardware

Question: On average, how many microscopic dust mites are in a double-sized bed? (200, 2,000, 2,000,000)

Answer: 2 Million - A double bed mattress can easily harbor 2 million dust mites, with each mite producing 10 to 20 waste particles (feces) a day. 

House dust may contain asthma triggers.

Using central vacuums or vacuums with high efficiency filters may be helpful.  

 Buyer Beware The air purifier and vacuum industries have enthusiastically jumped onto the HEPA bandwagon, and sales have grown astronomically. As a result, many products are tagged with the word HEPA. Label examples include "HEPA-like", "HEPA-type", and "99% HEPA". Products of this type are designed and manufactured to appear similar to true HEPA filters; however, they do not satisfy the same performance requirements. 

Q. Bob, We have a problem with ice on the inside of our windows (20 yrs old). This problem has been happening for 10 years. We want to replace the windows but are afraid there might be a problem other than the windows. We keep our heat on about 62 during the winter nights. Windows are wood framed. If you have an idea, I would appreciate hearing from you. Thanks, Dan

Q.  

Did you know BK can do an Air Check?

What Causes Indoor Air Problems?
Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some pollutants.

Pollutant Sources
There are many sources of indoor air pollution in any environment. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as pesticides, and outdoor air pollution. Some sources, such as building materials, furnishings, and household products like air fresheners, release pollutants more or less continuously. Other sources, related to activities carried out in the home, release pollutants intermittently. These include smoking, the use of unvented or malfunctioning stoves, furnaces, or space heaters, the use of solvents in cleaning and hobby activities, the use of paint strippers in redecorating activities, and the use of cleaning products and pesticides in housekeeping. High pollutant concentrations can remain in the air for long periods after some of these activities.

The Scope of the Problem
Most information about sources and health effects of biological pollutants is based on studies of large office buildings and two surveys of homes in northern U.S. and Canada. These surveys show that 30% to 50% of all structures have damp conditions, which may encourage the growth and buildup of biological pollutants. Some diseases or illnesses have been linked with biological pollutants in the indoor environment. This percentage is likely to be higher in warm, moist climates.

Health Effects of Biological Pollutants
All of us are exposed to biological pollutants. However, the effects on our health depend upon the type and amount of biological pollution and the individual person. Some people do not experience health reactions from certain biological pollutants, while others may experience one or more of the following reactions:

• Allergic
• Infectious
• Toxic

Except for the spread of infections indoors, ALLERGIC REACTIONS may be the most common health problem with indoor air quality in homes. They are often connected with animal dander (mostly from cats and dogs), with house dust mites (microscopic animals living in household dust), and with pollen. Allergic reactions can range from mildly uncomfortable to life-threatening, as in a severe asthma attack. Some common signs and symptoms are:

• Watery eyes
• Runny nose and sneezing
• Nasal congestion
• Itching
• Coughing
• Wheezing and difficulty breathing
• Headache
• Fatigue

Health experts are especially concerned about people with asthma. These people have very sensitive airways that can react to various irritants, making breathing difficult. The number of people who have asthma has greatly increased in recent years. The number of people with asthma has gone up by 59 percent since 1970, to a total of 9.6 million people. Asthma in children under 15 years of age has increased 41 percent in the same period, to a total of 2.6 million children. The number of deaths from asthma is up by 68 percent since 1979, to a total of almost 4,400 deaths per year.
INFECTIOUS DISEASES caused by bacteria and viruses, such as flu, measles, chicken pox, and tuberculosis, may be spread indoors. Most infectious diseases pass from person to person through physical contact. Crowded conditions with poor air circulation can promote this spread. Some bacteria and viruses thrive in buildings and circulate through indoor ventilation systems. For example, the bacterium causing Legionnaire's disease, a serious and sometimes lethal infection, and Pontiac Fever, a flu-like illness, have circulated in some large buildings.

Indoor Air and Your Health
Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later. Immediate effects may show up after a single exposure or repeated exposures. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. Sometimes the treatment is simply eliminating the person's exposure to the source of the pollution, if it can be identified. Symptoms of some diseases, including asthma, hypersensitivity pneumonitis, and humidifier fever, may also show up soon after exposure to some indoor air pollutants.
The likelihood of immediate reactions to indoor air pollutants depends on several factors. Age and preexisting medical conditions are two important influences. In other cases, whether a person reacts to a pollutant depends on individual sensitivity, which varies tremendously from person to person. Some people can become sensitized to biological pollutants after repeated exposures, and it appears that some people can become sensitized to chemical pollutants as well.
Certain immediate effects are similar to those from colds or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution. For this reason, it is important to pay attention to the time and place the symptoms occur. If the symptoms fade or go away when a person is away from the home and return when the person returns, an effort should be made to identify indoor air sources that may be possible causes. Some effects may be made worse by an inadequate supply of outdoor air or from the heating, cooling, or humidity conditions prevalent in the home.
Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure. These effects, which include some respiratory diseases, heart disease, and cancer, can be severely debilitating or fatal. It is prudent to try to improve the indoor air quality in your home even if symptoms are not noticeable.

Sometimes, a foundation problem is obvious such as when a large crack develops in the walls of your basement. However, there can also be other signs that your foundation is having issues that may not be as obvious. Knowing what to look for is important, and here are a few signs of trouble with your foundation that you should be aware of and pay attention to:

1. Sloping or uneven floors in the basement. This can be a sign that the walls and basement floor are starting to separate or pull away from each other. It is a serious issue and one you should deal with promptly by calling in a foundation repair expert.

2. Cracks or shifts in your crown molding. Crown molding is molding between your sealing and your wall. If your crown molding begins to pull away at the sides (i.e. in corners or where two pieces meet) this is a sign that your home is shifting and your foundation might be in trouble. This is especially true if the crack begins in the wall and continues up into the molding.

3. Cracks or gaps between the walls and ceiling. If your home does not have crown molding, then you may notice gaps developing between the wall and ceiling. This, too, is a sign that the foundation of your home is shifting and that your foundation needs attention.

4. Cracks on your home's exterior in the brickwork, or the walls separating form your home. This is an extremely serious sign of foundation problems and it means that you must contact an expert right away to preserve the structural integrity of your home.

5. Separation at the windows, doors or garage door. Essentially, like most of the other signs, shifting and pulling away of parts of your home that used to be tight are all indicators that your home's foundation is beginning to develop problems.

6. Inability to tightly or properly close windows and doors. If your foundation begins to sink, door frames may begin to sag and you may be unable to properly open or close doors. Likewise, a sagging or shifting foundation can cause your windows and doors to become out-of-square and more difficult to open or close.

If you begin to notice any of these issues with your foundation, it is very important that you contact an expert. The longer you wait, the worse the problems in your home may become and the more expensive it may be to fix all of the issues that have developed due to your sagging, shifting or damaged foundation. Don't hesitate to take action. With the right expert, you may be able to find a simple and easy solution to your foundation issues.