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Green Energy Services - Residential - Certified Energy Audits

Mechanical Air Service has been involved in the energy related servicing and auditing since 1976.

Mechanical Air Service, Inc. provides energy audit services to improve the energy performance of homes.  An energy audit helps to identify measures that reduce the energy use and associated costs of heating and cooling a home.  

Some of the services provided during an energy audit are:

1. Collect and analyze historical energy consumption for the past year.
3. Conduct site inspection of the heating and cooling systems and measure operational performance
4. Conduct a whole house Blower Door test to determine the amount of air leakage into the home and their locations.
5. Conduct a duct system air leakage test to determine if your duct system is leaking too much air. The California Energy Commission indicates residential duct systems leak an average of 30-50%.
7. Develop an action plan for economically viable measures

Blower Door Tests
Our Professional energy auditors use blower door tests to help determine a home's air tightness.
These are some reasons for establishing the proper building tightness:

  • Reducing energy consumption due to air leakage.
  • Avoiding moisture condensation problems.    
  • Avoiding uncomfortable drafts caused by cold air leaking  in from the outdoors
  • Making sure that the home's air quality  is not too contaminated by indoor air pollution.
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How They Work
A blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings. The auditors may use a smoke pencil to detect air leaks. These tests determine the air infiltration rate of a building.

Blower doors consist of a frame and flexible panel that fit in a doorway, a variable-speed fan, a pressure gauge to measure the pressure differences inside and outside the home, and an airflow manometer and hoses for measuring airflow.
Diagram of a blower door. The parts of the blower door are labeled as follows: exterior door frame (around the outside edge of the door), temporary covering (over the surface of the door), and adjustable frame (just inside the exterior door frame). An air pressure gauge, a small vertical rectangle with three round gauges inside, is alongside of the door. The top gauge is connected by a tube to the temporary covering, and the bottom two gauges are connected to a fan sitting at the bottom of the door. The caption reads: Diagnostic Tools. Testing the airtightness of a home using a special fan called a blower door can help to ensure that air sealing work is effective. Often, energy efficiency incentive programs, such as the DOE/EPA ENERGY STAR® Program, require a blower door test (usually performed in less than an hour) to confirm the tightness of the house.
There are two types of blower doors: calibrated and un-calibrated. It is important that auditors use a calibrated door. This type of blower door has several gauges that measure the amount of air pulled out of the house by the fan. Un-calibrated blower doors can only locate leaks in homes. They provide no method for determining the overall tightness of a building. The calibrated blower door's data allow the auditor to quantify the amount of air leakage and the effectiveness of any air-sealing job. Mechanical Air Service only uses calibrated blower doors.

Preparing for a Blower Door Test
Take the following steps to prepare your home for a blower door test:

  • Close windows and open interior doors
  • Turn down the thermostats on heaters and water heaters
  • Cover ashes in wood stoves and fireplaces with damp newspapers
  • Shut fireplace dampers, fireplace doors, and wood stove air intakes.

Ventilation
When creating an energy-efficient, airtight home through air sealing techniques, it's very important to consider ventilation. Unless properly ventilated, an airtight home can seal in indoor air pollutants. Ventilation also helps control moisture —another important consideration for a healthy, energy-efficient home.

Purpose of Ventilation
Your home needs ventilation—the exchange of indoor air with outdoor air—to reduce indoor pollutants, moisture, and odors. Contaminants such as formaldehyde, volatile organic compounds, and radon can accumulate in poorly ventilated homes, causing health problems. Excess moisture in a home can generate high humidity levels. High humidity levels can lead to mold growth and structural damage to your home.

To ensure adequate ventilation, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) says that a home's living area should be ventilated at a rate of 0.35 air changes per hour or 15 cubic feet per person per minute, whichever is greater.

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Ventilation Strategies
There are three basic ventilation strategies:

  • Natural ventilation
    Uncontrolled air movement into a home through cracks, small holes, and vents, such as windows and doors. Not recommended for tightly sealed homes.

  • Whole-house ventilation
    Controlled air movement using one or more fans and duct systems.

  • Spot ventilation
    Controlled air movement using localized exhaust fans to quickly remove pollutants and moisture at their source. Typically used in conjunction with one of the other strategies.

Air Sealing
Air leakage, or infiltration, occurs when outside air enters a house uncontrollably through cracks and openings. Properly air sealing such cracks and openings in your home can significantly reduce heating and cooling costs, improve building durability, and create a healthier indoor environment.

It is unwise to rely on air leakage for ventilation  because it can't be controlled. During cold or windy weather, too much air may enter the house. When it's warmer and less windy, not enough air may enter. Air infiltration also can contribute to problems with moisture control. Moldy and dusty air can enter a leaky house through such areas as attics or foundations. This air in the house could cause health problems.

The recommended strategy in both new and old homes is to reduce air leakage as much as possible and to provide controlled ventilation as needed.

Insulation
Properly insulating your home will not only help reduce your heating and cooling costs but also make your home more comfortable.

How Insulation Works
You need insulation in your home to provide resistance to heat flow. The more heat flow resistance your insulation provides, the lower your heating and cooling costs.

Heat flows naturally from a warmer to a cooler space. In the winter, this heat flow moves directly from all heated living spaces to adjacent unheated attics, garages, basements, and even to the outdoors. Heat flow can also move indirectly through interior ceilings, walls, and floors—wherever there is a difference in temperature. During the cooling season, heat flows from the outdoors to the interior of a house.

To maintain comfort, the heat lost in the winter must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease this heat flow by providing an effective resistance to the flow of heat.

An insulation's resistance to heat flow is measured or rated in terms of its thermal resistance or R-value.  

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