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Understanding Window Issues and Energy Efficient Options

Understanding Window Issues and Energy Efficient Options

Even the most optimistic among us must now expect rising costs to have a dramatic impact on our utility bills in the near future. As oil, natural gas and coal prices rise, the cost of utilities also goes up, due to increased operating costs.

It is fast becoming a matter of financial necessity for everyone (governments, institutions, businesses, and home owners alike) to be able to identify energy inefficient problem areas throughout our structures. While the promotion of energy efficient appliances and lighting has become popular and is a good starting point, the single largest consideration regarding energy efficiency is our building envelope.

The Building Envelope

(what is it and how does it work?)
Your building's "shell" or envelope is made up of windows, outside doors, walls, foundation, floor, roof, and skylights. The envelope is the barrier between the carefully controlled, temperate indoor environment you maintain inside your building and the fluctuating outdoor environment. By allowing or blocking certain amounts of light, fresh air, heat, cooling and humidity, the envelope functions like a selective filter to make the indoor environment more comfortable. If the envelope works well as a barrier and as a filter, you will use less energy in your lighting and HVAC systems to control the light, temperature, humidity, and fresh air levels.

The Cost-Saving Objective

Even with a very good envelope, a building will still loose heat in cold weather and gain it when it is hot outside. Your basic cost-saving objective is to minimize the cost to correct these loses and gains. In the book "The Energy Efficiency Guide for Businesses, Industry, Government and Institutions" Third Edition on their segment titled "Envelope", the objectives to minimize energy costs caused by unwanted heat loss and unwanted heat are clearly stated.

These objectives are to; stop infiltration, reduce heat transfer, control humidity, and control sunlight.

  • Stop Infiltration. Prevent the leaking in of outside air, and likewise prevent the leaking out of inside air you have paid to heat or cool, through openings such as cracks in walls around windows, and where doors don't fit or close properly.

  • Reduce Heat Transfer. Minimize the transfer of heat through materials in the building envelope by conduction and convection. Heat always flows from a warmer environment to a colder one. All materials conduct heat, but some, such metal or a single pane of window glass, conduct it faster than a substance such as fibreglass, which is a poor conductor and therefore a good insulator.
    "R" value is a measure of resistance to heat flow; the higher the "R" value number, the higher the resistance. There are various ways you can increase the "R" value of your roof, walls, floor, and windows, to reduce the transfer of heat from one side to the other.
  • Control Humidity. Control the movement of water vapour in and out to achieve appropriate humidity levels. For health, comfort, and protection of materials such as wood, relative humidity should range between 30-60%. Vapour barriers and ventilation can prevent condensation and associated rot and mildew problems.
  • Control Sunlight. By letting in the sun's light and heat or blocking them out when not wanted, you can reduce levels of artificial light, heating, ventilating, and air conditioning loads.

The Truth About Windows

Windows are the weakest part of the building envelope and account for heat gain in the summer and heat loss in the winter. The transfer of heat inside (heat gain) through the windows in the summer raise's cooling costs and the transfer of heat outside (heat loss) through the windows in the winter raises heating costs. In reality windows are thermal holes. Single pane clear windows are 20 times less energy efficient than the wall area they replace and double pane Low-E windows are 10 times less energy efficient than the wall area they replace. What that means is that an average building (home/office) can lose more than 30% of its heat or air conditioning energy through its windows. And while the amount heat loss or heat gain through windows depends on whether the windows are single pane glass, clear double pane, Low-E coated, or gas filled, the fact is if you have windows you have heat gain and or heat loss every day of every year.

Typical Window Performance in the summer

In summer windows provide desirable daylight and a view, but also allow infiltration, unwanted glare, heat gain, plus damaging UV rays to enter buildings. The damaging results include increased greenhouse effect, increasing interior temperatures, and cooling costs, decreasing comfort, and productivity in work environments, not to mention the UV damage to furniture, carpets, etc.

Typical Window Performance in the winter

Winter Windows
While windows allow daylight and solar gain which we want in the winter they also allow the sun's damaging UV rays to enter through the windows. Additionally, heat escapes through the windows at night and daily through windows when it is colder outside than inside. There is also heat loss due to exfiltration (air leakage).

The Solution
The Advantage Window Systems research and development team found only one product world wide that effectively addresses the energy inefficiency problem of heat transfer through windows, and subsequently offers the ability to reduce utility consumption.

"In-Flector", is a "see through radiant heat barrier window insulator", and the 1st line of defence against the transfer of heat in and out of buildings through windows.

In-Flector Window Insulators are pioneers in window efficiency. The patented one way heat transfer reversible In-Flector is an engineered solution which addresses more than just the reflectance of solar heat gain. In-Flector Window Insulating material was designed to address all deficiencies of the building envelope pertaining to windows by effectively giving you beneficial control over reflectivity, emissivity, absorption, radiant heat gain, solar heat gain, privacy, infiltration, condensation, heat loss in the winter, as well as being a passive solar collector, absorbing sunlight and radiating free heat into building.

The reversible In-Flector window insulating material puts three useful properties to work for you: reflectivity, emissivity, and absorption. The key is the product's design.

The reflective silver side (aluminum side) was chosen for two reasons;

  1. to reflect solar heat gain back out through the window;
  2. and most importantly aluminium has a low emissivity of between 0.03 and 0.05. This means that only 3% to 5% of radiant heat is emitted through the aluminium; reflecting the heat in the direction the aluminum side is facing;
  3. absorption, the reverse side (black side) of the patented system is a passive solar collecting one way heat transfer material absorbing the suns rays and radiating heat into the building thus reducing the amount of heat the heating system is required to generate.

In fact In-Flector Window Insulators address all of the seasonal changes throughout the year keeping the heat in the building during the winter, while keeping the heat from entering the building during the summer.

"In-Flector" "See Through Radiant Heat Barrier Window Insulator"

Summer Benefits and Value

Summer Benefits
In the summer the In-Flector Window Insulator are positioned so that the silver side faces out and reflects 72% of radiant heat back out through the window (reducing the greenhouse effect in buildings). It also reflects 65% of solar gain back out through the window (reducing overheating in buildings); and reflects 92 % of damaging UV rays back out through the windows (reducing fading & sun damage); controls glare (especially for computers & televisions); provides daytime privacy (one way vision); provide cool day lighting with a view; reduces the load, wear, & maintenance on HVAC units. It reduces cooling requirements which reduces energy consumption, saving you money.

Winter Benefits and Value

Winter Benefits
In colder climates in the winter the In-Flector Window Insulators are reversed so that the silver side (aluminium) is facing inward, reflecting the thermal heat back into the building reducing heat loss through the windows. For windows that have direct exposure to the sun the black side of the In-Flector faces outward and acts as a passive solar collector absorbing the suns rays and radiating the heat inward. As an example, a 4 X 4 window in direct sunlight can produce 2096 BTU's of heat per hour, which is equivalent to a 600 watt electric heater. Meanwhile the damaging UV rays are reflected back outside. Here the In-Flector Window Insulators reduce the load, wear, & maintenance on HVAC units. It reduces heating requirements, which reduces your heating costs, and saves you money.


Reducing heat gain through the windows in the summer reduces energy consumption for cooling and reducing heat loss through the windows in the winter reduces energy consumption for heating.

Energy inefficiency with windows should be a concern to everyone. The fact is utility costs are going to keep rising; at what point and time does reducing the consumption of utilities become a priority.

Contact your Local Representative to arrange for an "In-Flector" product demonstration. Representatives can also provide current and previous residential, business, and government installation photographs, plus testimonial letters.

Ken Crooks
Radiant Barrier For Windows
5102 Indian Trail Ct.
Colleyville, TX  76034-3099
Phone: 817-437-9497
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