Air Sealing a House-Ventilation and Air Changes

House Systems

A House Is A System:

A house is a system and is made up of interconnecting parts both mechanical and physical components. If all the parts are working together correctly your home will have the following attributes associated with it.

1. Comfortableness

2. Safety

3. Efficiency

4. Durability

So by looking at your house as one complete system of interconnected parts your savings can mount up and well create a safe and healthy environment.

Air Sealing and Proper Insulation:

If your home is properly air sealed and insulated it can greatly lower the heating and cooling load of your home. Along with a properly insulated and sealed home comes benefits.

For Example: 

If you wanted to replace an existing furnace with a smaller furnace, you will spend less money and your long term operating cost will be a lot less.

See back in in the olden days people believed that their homes had to breathe, so they left them loose which they thought it would create good indoor air quality in both the spring and fall months, which it did at the sacrafice of increased heating and cooling cost during the summer and winter months.

With advancements in building supplies and technology the improvements people are making to their homes today are finding out that “tighting up their homes” is more beneficial now than ever and by doing so they are not only creating good indoor air quality throughout the year but also reducing their heating cost in winter months and the cooling cost in summer months.Sealant for Holes

Plugging Holes or not Plugging Holes:

A home that is correctly air sealed and mechanically ventilated will have great air exchange all the time.

So what holes are we to plug?

1. Attic:

a. Seal up any small holes that you might see in the attic floor which can be found at pipe areas, wire areas, and or the
chimney chases, by doing so this will not allow heated air from the below living spaces to enter the attic.

b. Make sure the living space is properly insulated while at the same time the roof remains the same temperature as the outside air, thus stopping cold air that is traveling from outside through the attic space area into the living space area. This can be done by having a great venting system which is a must in order to vent the roof correctly making sure that there is no obstructions seen that will stop the air flow entering through soffit-intake vents and out through ridge vents, gable vents and or louver vents.

c. Prior to installing any insulation in the attic make sure you seal attic-to-home air leaks. You must know that insulation does not stop airflow.

d. Always look to see if the attic ceiling shows no water stains or marks. This is an sign that there might be current or past leaks. If any moisture is on the insulation it can cause future problems that can damage a home and affect the air quality of a home.

e. Install metal flashing for heat-producing equipment (fire-safety clearance requirements are usually 3 inches) around flues, chimneys, exhaust fans, and light home fixtures but if the homes light fixtures are insulation contact rated, they are airtight and can be covered with insulation.Metal Flashing Tape

2. Chimney Chases:

a.  The worst place to have a vertical hole in a house is around the Chimney Chase especially from an Energy Perspective. A unsealed Chimney Chase’s heat will cause the air column around it to suck air from the basement and pressurize the attic. The humid air drawn from the basement into the attic space can cause roofs to prematurely fail. Make sure the air seal from the chimney to the ceiling below is completed.

b. Seal around chimney and framing with a high-temperature caulk or
furnace cement.

3. Additional Holes To Seal Up:

a. Leaky recessed light fixtures in the ceiling will increase heat loss and gain, which inturn can cause ice dams and
moisture problems damaging the Roofing System of the home.

b. Underneath tubs and kitchen sinks is a good place to look for sealing up plumbing penetrations through the floor or wall cavity areas.

Proper Insulation Makes a Huge Difference!!Proper Atic Insulation

Heating and cooling costs can be reduced by up to 20% per year by correctly insulating the home. The attic space should be the number one place when it comes to stopping heat loss. Because heat rises, there can be a large amount of heat loss from the living areas of the home. Heat that is trapped in the attic during summer months can reduce a home’s ability to stay cool, forcing the occupants of the home to utilize their air condintioning unit much more than needed.

What To Look For?

Think about these things before installing the insulation, proper preparation of the attic will ensure that the insulation is applied correctly to prevent hazards and to achieve ultimate effectiveness.

1. Ensure that there is a free flow of outside air from the soffits to the roof vents, inadequate
ventilation in insulated attics is common.

2. Look behind the baffles to see if there is insulation obstructing the natural air flow while
checking the roof vents to make sure that outside air is exhausting properly.

3. Check for a moisture barrier underneath the insulation.

4. Check for look for any locations where the insulation is compacted or missing completely.

Mechanical Ventilation Is Essential!!

Today’s homes should have a good balance of indoor air quality and energy conservation. Homes that are not tightened up enough can lead to moisture intrusion and no odor control. Improperly installed Mechanical Ventilation does waste energy and leads to bad indoor air quality.

Some Types of Mechanical Ventilation include the following:
Bathroom and Kitchen Fans,Clothes Driers and
Central Heating and Cooling Systems, depending on the type installed and used will determine Proper Ventilation and Atmospheric Air Changes .


Homes and buildings are built very differently than those built 30 to 40 years ago. Our economy is moving towards
tighter houses along without the safety of the occupants in mind. Depending on how tight a house is will determine how individual components react with one another.

If you ever have any questions, feel free to leave them below and I will be more than happy to help you out.

All the best,

Troy Halstenson (Founder of Performance Air and Heating)


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