Do all Low-E coated glasses look the same?
No, they do not. Color differences between various low-e coatings are due to the use of different coating materials, the thickness of the various coating layers, as well as differences in manufacturing processes.
Will Low-E glass work only in northern climates?
No, low-e coated glass can work in all climates.
Low-e coatings reduce heat loss from the interior through windows, thus reducing the energy used to heat buildings and associated heating costs.
And, low-e coatings also offer solar control that reduces heat gain due to both the transmitted solar energy and conducted heat caused by indoor – outdoor temperature difference. This reduces cooling loads and consequently the energy and costs associates with cooling the building.
What is required to maintain a PPG Low-E glass product?
Since all PPG MSVD low-e coatings must be sealed within an insulating glass unit, no maintenance is required. If Sungate 500 low-e glass is used in a single glazing application, or as a storm window, then normal cleaning with a mixture of 50% water and 50% isopropyl alcohol is recommended.
Do Sungate Low-E coatings work as well at night (when the sun isn't shining)?
Sungate Low-E coatings work 24 hours a day. In the winter, they reflect the heat (long-wave infrared energy) back into the interior, day and night. Low-E coatings do not differentiate between furnace heat and heat created by solar energy, as they are both absorbed and re-radiated as long-wave infrared energy.
How do SUNGATE and SOLARBAN coated glasses reflect the heat?
First, heat is transferred in three ways: Conduction, convection, and radiation. SUNGATE and SOLARBAN coatings directly affect only the radiated component of the heat transfer. The coatings incorporate an extremely thin metallic layer that reflects the radiated energy (heat), similar to the way a mirror reflects light.
How can PPG Low-E work both in the summer and winter?
Winter
- In the winter, PPG Low-E glass keeps more heat inside by reducing the amount escaping though the glass and therefore reduces heating bills.
- Some heat (long wave infrared) is not permitted to enter the home, but this is outweighed by the benefits of the amount of extra heat kept inside (much less heat escapes).
- Some short wave infrared is still allowed to enter the home and is converted into heat.
Summer
- In the summer, PPG Low-E glass reduces the amount of heat that enters through the glass thus reducing the solar heat gain and decreasing cooling costs.
In General
How much does PPG Low-E glass reduce the transmission of ultraviolet (UV) energy?
The reduction in the transmittance of UV energy is dependent on the specific PPG low-e coating and the make-up of the insulating glass unit, i.e., glass thickness, glass type, etc. Please refer to the product performance charts elsewhere on the PPG Website for specific information.
Will PPG Low-E glass affect my plants?
First, in addition to the glass and low-e coating, other factors such as the available solar energy and angle of incidence (season of the year, latitude) and specific plant type need to be considered. Also, environmental factors such as temperature, relative humidity, and potential contaminants are important factors. A horticultural specialist is best suited to address specific issues and plants.
However, the following is offered to help with your decision:
The wavelength of radiant energy used during photosynthesis is between 320 and 700 nm.
The maximum % energy transmitted by SOLARBAN 60 coated glass, for example, is between 400 and 700 nm, the same energy range as that primarily used by plants. For comparison, the total visible light (380 to 770 nm) transmitted by a 1” clear insulating glass unit (2 lites of ¼”clear glass with a ½” airspace) is 79% versus 69% for a similar unit with a SOLARBAN 60 coating. While this is a decrease in useful solar energy being transmitted, it is less of a decrease than going from unobstructed outdoor growth to growing behind clear glass, or the reduction that may occur simply by placing plants further from the windows.
In general, most plants that can be grown behind a clear glass window would also be expected to grow behind SOLARBAN 60 coated glass units.
What is the payback on PPG Low-E windows?
The amount of time that it takes to recover the cost of using low-E in windows from heating and cooling fuel bill savings varies. A number of factors affect the period of time:
- The quality of installation of the window
- The quality of workmanship of the window
- How warm or cold the seasons are compared to usual, especially winter
- Whether windows are kept open in the winter
- The amount of shading from large trees or from blinds
- Geographic location
- One thing that you can count on is that PPG Low-E windows will make the home a more comfortable one.
Does a window with PPG Low-E glass appear any different from a regular window?
There is a slight difference in appearance, but this difference is extremely difficult to see between windows in different parts of a home or building. If you install a lite of low-e glass directly next to a lite of clear glass, you will most likely notice a slight difference. If you install all low-e glass on a particular building, it is a low probability that the typical observer will know that it is any different than clear glass.
Will I notice a difference in the amount of sunlight through my windows if I replace clear glass with Low-E glass?
Initially you may be aware of a slight reduction in the intensity of light coming into your building compared to your old windows. When sunlight is coming directly through windows in which clear glass has been replaced with low-e glass, most people say that the low-e is more comfortable because they feel less heat and glare from the sun. An insulating glass unit with Solarban® 60 solar control low-e glass, transmits about 13% less visible light than an insulating unit with all uncoated clear glass, and about 48% less total solar energy.
What is ultraviolet (UV) light?
The sun’s energy, or solar energy, includes ultraviolet, visible, and infrared energy. Ultraviolet light or UV is short wavelength energy with wavelengths from 290 to 380 nanometers. It is invisible and accounts for approximately 2 percent of the solar energy that reaches the earth. A 1” insulating glass unit with Solarban® 60 solar control low-e glass allows only about 14% of the UV that reaches the earth to pass through the insulating glass unit.
Do blinds, shades, trees, and awnings affect the way that my windows perform?
The answer is yes and no. These items may restrict the amount of heat and light that enters the home through the windows, but they do not change the functional properties of PPG low-e glass.
Should I put PPG Low-E glass in my windows on all exposures and not others?
- PPG Low-E glass can improve window performance for all exposures all year round.
- In the winter, PPG Low-E is a benefit because it retains heat no matter which direction the window is facing.
- Therefore, PPG Low-E is especially useful on north-facing windows in winter because they resist heat loss.
- PPG Low-E is useful for east, west, and south facing windows because it will reduce solar energy transmission.
- At the same time, the PPG Low-E is a benefit for these exposures because at night the window is saving money by preventing heat from escaping
Can tinted glass be used with Low-E glass?
Yes it can. Tinted glass can be used as the outdoor lite in an insulating glass unit, with PPG Low-E as the indoor lite. The low-e coated glass improves the insulating properties of the insulating glass unit, while the tinted glass reduces the influx of solar energy through the insulating unit.
How effective is tinted glass with PPG Low-E coatings?
- Tinted glass is very effective when used in conjunction with PPG Low-E glass. This combination will reduce excess heat gain and lower cooling costs.
- The tinted glass reduces the amount of excess heat gained on east, west, and south exposures
Is it any harder to clean windows that contain PPG Low-E glass?
No. If your windows have PPG low-e glass, the low-e coating is glazed inside a sealed insulating glass unit. The coating is not exposed to the atmosphere. The indoor and outdoor surfaces of the insulating glass in your windows are plain uncoated glass surfaces, and will clean like normal glass.
How do I know that my window actually has Low-E glass?
Low-e glass is plain sheet of glass that has a coating put onto one of its two surfaces. To improve the insulating properties of windows, that plain sheet of glass is put together with another piece of glass to make a sealed insulating glass unit. The low-e coating goes inside the insulating unit.
You can test for the low-e coating in a window by doing the following:
- Hold a match or a pen light up in front of the window. You will see four reflections of the flame from the match or the light from the penlight when you look at the glass.
- If you have low-e, one of the images will be a different color than the rest of the images.
- If your window has no low-e, the four reflected images will be the same color.
How does argon gas work?
Insulating glass can be made with air between the lites of glass or it can be made with other gases between the lites of glass. Putting argon inside the insulating glass in a window improves the insulating value of the IG unit and the overall window. The bottom line is, less heat flows through a window with argon between the lites of glass than through a window with air between the lites.
Is Argon Gas Dangerous?
Argon gas is an inert gas and it exists in small quantities in the atmosphere around us. We breathe it everyday, and it is harmless. It is not toxic nor is it poisonous to humans. However, you could not breathe only argon. Your body needs other components of the atmosphere to live. Argon gas that is inside insulating glass units is not dangerous.