Posts Tagged ‘insulation’

Is Your Thermal Envelope Robbing You Blind?

Tuesday, December 1st, 2009

Is your home’s envelope robbing you blind?

Many homeowners conclude that their home is indeed robbing them. To solve this problem, homeowners can secure their home’s thermal envelope with energy tax credit- approved insulation, windows and doors. By improving the thermal envelope of the home you’ll stop the highway robbery that occurs through excessive energy bills each month– and you may qualify for an energy tax credit if the improvements come on line during 2009 or 2010.

The envelope of the house is comprised of the windows, doors, skylights, ceiling, roof, walls, floors and the insulation that covers these surfaces, vents and outlet boxes. Energy efficient windows, doors and insulation provide the critical barrier to the transfer of heat needed for a proper thermal envelope around the living quarters.

Think of the thermal envelope like the outer wear that family members put on in the frigid winter months. Without an adequately insulated coat, hat and gloves heat loss can occur. Exposed skin can freeze inside of minutes.

Similarly, a house that has gaps or inadequate levels of insulation within the thermal envelope will leak energy and make the home uncomfortable and expensive to operate.

Insulation is a major component of this protective barrier between the outside elements and your family’s comfort. Unfortunately, most builders will only add insulation to the ceiling, walls and floors to the level required by local building code. This is usually inadequate to meet modern energy efficiency standards.

According to the Energy Star insulation value chart the R values (or level of heat transfer resistance for insulation) should be between R-25 and R-49 for walls; between R-30 and R-60 for ceilings and R-13 and R-30 for floors. The exact amount will depend on your climate zone.
When you add insulation your family will notice that temperatures within the house will even out during all seasons. Energy Star says that you will save up to 20% on heat and air conditioning bills each month. The other benefit is that if you add insulation to the appropriate R value for your area, you may qualify for the energy tax credit for 2009 or 2010.

The other major culprits robbing your home of its heat and cooling power are your windows, doors and skylights. Energy Star says that as much as 25% of energy loss occurs through the windows.

Framing around doors must also be tight in order to keep the envelope secure from heat transfer. Doors should be flush with the frame and there should be seal pads on the inside of doorstops. It is more the framing than the door itself that determines energy efficiency in the doors.

As of June 1, 2009 the federal government tightened the rules on window energy efficiency in order to qualify for the energy tax credit. Prior to that date any Energy Star window qualified, but for windows put into service after June 1, 2009 the windows must have a U-factor and a Solar Heat Gain Coefficient (SHGC) of less than .30. These are measures of heat loss and amount of sunlight blocked respectively. Windows and doors approved for the federal tax credit must also be certified by the International Energy Code Council (IECC) to qualify for tax credit.

Making a home improvement of the thermal envelope has lots of benefits that will last for years to come. Your family will be more comfortable. You will save $100 or more per month on energy bills in most cases. Imagine, after 10 years a total savings of $12,000 or more! That could put a kid through college for a year or take care of several months of expenses in retirement. In addition, the home improvements put into action in 2009 or 2010 may qualify for an energy tax credit of 30% of the cost of the project (less installation) up to $1500. Last, but not least, you’ll be helping the environment by cutting down on the use of fossil fuels.

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