:: Reducing carbon dioxide emissions in a a 35 year old home ::

I currently reside in a 2,600 square foot single story 100% masonry home that is 35-years old.  The home and roof are heavily shaded by Oak and Pecan trees.  I’ve been considering ways in which an older home can reduce carbon dioxide emissions (and energy loss via upgraded insulation), a threat as great as that of vehicles to the atmosphere in advancing global warming. 

We just replaced the complete heating and air system with the highest rated one on the market (or available in Texas anyway).  This also prompted me to begin considering our inexpensive leaky aluminum frame windows, many of which have broken seals and which are single-pane.  Plus, as a cost-cutting measure, these are what were selected at the time the house was built.  It’s time they were replaced.  Recycled aluminum, double paned, UV rated, UL rated, etc. windows which are better looking as well.

According to UK sources, cost-cutting and energy savings, as well as emissions reduction can occur in older homes as well as those built today.

Residential energy saving measures could cut millions of tonnes of carbon dioxide emissions and save householders billions in fuel bills, a new Government report has shown this week. The initial report from the Review of the Sustainability of Existing Buildings found that practices as simple as cavity wall insulation could help contribute to the green benefits if implemented on a widespread basis.

Up to 7m tonnes of carbon per year could be saved from household emissions by introducing measures with the ‘fastest payback’ such as cavity wall insulation and boiler replacement, states the research.

“This research suggests our existing homes and buildings could offer some of the most cost effective ways to cut our national emissions over the next few years. After all, many of the measures needed to cut carbon from our homes also help cut our fuel bills as well,” commented Yvette Cooper, Housing and Planning Minister, in a speech to the All Party Parliamentary Group on Climate Change.

“To make the difference we need by 2050 we will need radical changes to the way we heat and power our existing homes as well as new ones. Whether it be turf on the roof, wind turbines in the garden, heat pumps below the basement or micro CHP boilers, the homes of the future will need to be powered in a completely different way. And we need to develop the technology to support our Victorian terraces and sixties tower blocks as well as our modern new homes,” added the Minister.

An acqaintence out of California also told me of a new roofing product which has the appearance of vaulted tile roofs that are solar collecters.  Some days, I just love technology.  Unfortunately, we recently replaced our roof at great expense.

Back to windows.  The Green Consumer Guide also has straight forward answers about windows:

Typically double glazing using Low-E glass has energy conservation properties as good as normal triple glazing but without the 50% increase in weight.

The advantages of using Low-E glass are:

• Better heat insulation
• You save money with reduced heating bills
• Reduced carbon dioxide emissions into the atmosphere
• Reduces condensation on your window frames internally

Installing argon gas within the sealed units instead of air can have even greater energy savings. Argon is an inert gas, which has better thermal properties than dry air. In the UK we express the rate of heat loss in ‘U values’. The lower the U value, the greater the thermal insulation and savings on your fuel bill.

Typical U values:
The U value of single clear glass is 5.4
With ordinary double glazing this is improved to 2.6
With Low-E glass the U value is reduced to 1.8
If argon gas is used to fill the air gap, the U value will reduce to 1.6

Let’s check U.S. Sources. 

According to Green Sage, these window manufacturers create LEED eligible widows:

		Accurate Dorwin Windows Fiberglass window frame system of high-effiency insulating glass. “Pultruded,” continuous strands of glass saturated in thermoset resin pulled through a heated die. Performs well in extremes of temperature and humidity. LEED eligible.
		Andersen Windows, Inc. Energy efficient with low-e coatings and argon gas-filled glazing. Series 200 features a streamlined selection of their most popular sizes and options. Series 400 features extensive sizes, shapes and styles. Andersen’s replacement window program produces “renewal” windows from remanufactured old windows they’ve replaced. LEED eligible.
		Pella Corp. Solid wood construction from pine or fir, weatherstripping and air infiltration exceeding industry standards make Pella a solid energy efficient choice for both windows and doors. Glass options for different climates,with low-e coatings. Energy Star® ratings on many of Pella’s products. “SmartSash®” wood windows and doors with removable glass panel. LEED eligible.
		Thermotech Windows, Ltd. Energy-efficient fiberglass frame windows with triple panes, low-e glazing and argon gas infiltration. 4 different insulating glass options. Promotes use of different glazings on different orientations to optimize energy performance. LEED eligible.

Whole Building Design Guide: 

In 1990 alone, the energy used to offset unwanted heat losses and gains through windows in residential and commercial buildings cost the United States $20 billion (one-fourth of all the energy used for space heating and cooling).

In recent years, windows have undergone a technological revolution. High-performance, energy-efficient window and glazing systems are now available that can dramatically cut energy consumption and pollution sources: they have lower heat loss, less air leakage, and warmer window surfaces that improve comfort and minimize condensation. These high-performance windows feature double or triple glazing, specialized transparent coatings, insulating gas sandwiched between panes, and improved frames. All of these features reduce heat transfer, thereby cutting the energy lost through windows.

This Resource Page covers basic concepts for specifying window and glazing systems, particularly energy-efficient windows.

I won’t provide the entirety here, suffice it to say, this is a very thorough guide and has similarity to the UK information but is a more precise and detailed display of window data.

I have some choices to make.  I also better check my financial resources.  It’s going to hurt, one way or the other.