Low-E and Your Replacement Windows

When you're doing your research on replacement windows, you will come across a whole lot of crazy terminology.  One of those terms is something called "low-e".  Let's take a look at what this means.

Low-e stands for "low emissivity".  Emissivity is a measure of the effectiveness in emitting radiant energy.  You can also think of it as the inverse (i.e. opposite) of reflectivity.  If something has low emissivity, it means it emits more radiant energy.  This would mean that it reflects more radiant heat.

In most modern replacement windows, low-e coatings are applied directly to one (or more) of the panes of glass.  On double and triple pane windows, the coatings are applied to the inner side of the glass.  In the summer, this helps keep the radiant energy outside of your house.  In the winter, this helps keep the radiant energy inside your home.

 Most new windows come with "soft coat" low-e.  This is a newer technology compared to the older "hard coat" low-e coatings.  On double pane windows, there is usually just one coat of low-e in the window.  On triple pane windows, there may be one or two coats, depending on the quality of the window.

Most people in the US live in an area where they need low-e glass.  So when doing your research, make sure to consider this vital criteria.  And as always, if you're considering replacement windows in Cincinnati, make sure to give us a call directly.  We'd be glad to answer any questions.

All the best!
Mike G.
The Window & Door Guy

How to Understand Window Ratings

So you're shopping for replacement windows, and you keep hearing all different types of numbers and figures being thrown around about them.  From energy efficiency to strength ratings, these things can get overwhelming.  

So what I've put together is a straight-forward guide to window ratings.  What they are, what they mean, and how to read them (is a lower U-factor better, or a higher one?).  

So here are the most important window ratings:

U-Factor

• The lower the U-factor, the better.
• The lower the U-factor, the greater a window's resistance to heat flow and the better its insulating value. It is a number between 0 and 1.
• Industry standard windows usually have a U-factor of 0.30 or lower.

Design Pressure (DP)

• The higher the DP, the better.
• The design pressure measures the strength and resiliency or a window, specifically how much pressure it can withstand without suffering breakage or damage.
• The higher the number, the stronger the window, the less air infiltration, and the longer it will perform to specifications.

Air Infiltration

• The lower the number, the better.
• A measure of air leakage per minute around a window, which is expressed as cubic feet per minute, or CFM. The lower the CFM, the better its air tightness.
• Industry standard is 0.30 CFM or lower.
• One CFM equals 7.5 gallons of air per minute leakage.

Water Penetration

• The higher the number, the better.
• Measures the ability to withstand water pressure in pounds per square foot, or PSF.
• Industry standard is 4.0 PSF or better.

R-Value

• The higher the number, the better.
• The R-value is simply the inverse of the U-factor. Meaning the R-value = 1/U-factor.
• As in the U-factor (above), this measures heat conductivity.

Solar Heat Gain Coefficient (SHGC)

• The lower the number, the better.
• The fraction of solar radiation admitted through a window, both directly transmitted, and absorbed and subsequently released inward.
• Expressed as a number between 0 and 1.
• The lower the SHGC, the less solar heat it transmits.

Visible Transmittance (VT)

• The lower the number, the more light the window blocks.
• It is the fraction of light transmittance through the window, measured between 0 and 1.
• Personal preference and circumstances my determine the desirable VT for you.

Condensation Resistance

• The higher the number, the better.
• Measures how well the product resists the formation of condensation.
• Expressed as a number between 1 and 100.

I hope this helps.  If you have any questions, please feel free to leave a comment below.  And as always, if you're interested in talking to the best replacement window company in Cincinnati, you can reach out to me directly by giving Windows Plus a call.  

Thanks for reading!

Mike G.

The Window & Door Guy

Welcome to the Window & Door Guy

Welcome to the Window & Door Guy blog!  Here I will be discussing all types of things windows and doors.  From energy efficiency to design, construction materials to glazing options, this blog will be your source for windows and doors.

But a little about myself first.  I am the marketing manager of a Cincinnati window company called Windows Plus.  I also work in sales here, so I really have two (completely) different jobs here.  But I love working for this company.  Windows Plus has been offering replacement windows, storm windows, entry doors, and glass patio doors in the Greater Cincinnati area since 1982.  It's a privately owned, locally owned, and debt free company.  It's also steadily becoming one of the biggest window companies in Cincinnati.  Something I'm proud to be a part of!

I'm going to be talking about all types of things on this blog.  But most importantly, I'm going to try to focus on what the average homeowner wants to know:

• How to tell the difference between different windows
• What makes an energy efficient window
• How to choose the right window for your home
• Different construction materials
• Differences in multiple glass panes
• What makes an energy efficient door
• ... and more!

So I hope this blog proves helpful to anyone wanting answers.  I will happily be taking up topic suggestions, so leave a comment if you want me to cover a specific topic.

Thanks for reading!

Mike G.

The Window & Door Guy