Energy Efficiency and what to look for in hurricane windows
If energy efficient windows are important to you, you can go the whole nine yards and have vinyl impact windows insulated with argon gas with Low E installed. However, depending on the manufacturer you choose, these can cost you 30-50% more than good aluminum impact windows or doors. Also keep in mind that in warm climates like South Florida the SHGC is much more important to keep the heat out than the U factor to keep the heat in.
Looking for Strength?
If strength is your priority, you can upgrade to SGP Interlayer by DuPont. This impact glass boasts five times the strength of a normal PVB interlayer but maybe a little overkill unless it is important to you. SGP is used for federal buildings mainly for ballistics and comes with a cost of around 20% more.
PVB (Polyvinyl Butyral) layer installed between two panes of glass 5/16 or 7/16 thick will provide adequate protection and is rated for Category 5 hurricanes. This will save you money, and it is best to put your money into energy-efficient windows and doors or upgrade to a new look like French doors or casements if that is the style you like. Whether it is 5/16 or 7/16, does not indicate the strength of the window; that is determined by the psi rating not the thickness of the glass. Some manufacturers offer heat strengthening which adds to the strength of the glass. This is not necessary unless you’re in a condo unit above five stories or in Zone 5 (within 5% of the end of the building).
Vinyl or Aluminum?
Keep in mind that aluminum impact windows are stronger than vinyl impact windows and can cover larger spans. Vinyl frames are a little more energy-efficient, but most experts, including the Florida Building Department and Florida Solar Energy Center, agree that in South Florida it is better to put your money in more energy-efficient glass, specifically Low E. Vinyl is used more often in northern climates to help keep heat in. Vinyl can also be beneficial for people living adjacent to the ocean or Intracoastal Waterway. Vinyl windows usually come with a lifetime guarantee, but the cost of the warranty is actually built into the price of the windows, thus increasing the cost.
Solar Heat Gain Coefficient (SHGC) Ratings
The National Fenestration Rating Council (NFRC) provides standards for energy efficiency in impact and other types of glass. Keep in mind that just because a window has an NFRC certification label does not mean a window or door is energy efficient. Rather, it provides information about energy performance that users can then use to determine if the product is efficient for the region or situation. You’ll note the label contains other information as well, including company name, framing material, product type, etc., so be sure to compare products.
In Florida, the Solar Heat Gain Coefficient (SHGC) rating is the most important since the main goal is typically trying to block the most heat from coming in to the home. The lower the number, the greater the heat-blocking ability. Here are some of the ratings from some of the most popular impact window options:
- Clear, non-impact glass (single pane:) SHGC 0.090
- Clear, impact window: SHGC 0.060
- Tinted gray or bronze impact window: SHGC 0.050
- Impact window adding Low-E: SHGC 0.0
- Low-E will usually cost around 5-10% more depending on the manufacturer but is usually the best value.
- Impact windows, with insulated glass with argon gas: SHGC 0.022
- Typically costs around 12-20% more depending on the manufacturer)
- Impact windows, vinyl frame, insulated glass with argon gas, with Low-E: SHGC .020
- Typically costs 30-35% more for windows.
- Can cost up to 50% more for sliders and french doors.
We at Assured Storm Protection offer you the best impact windows and doors. All the manufactures we use will do the job, but we try to bring you the best quality at the best price. We often do this by mixing brands since frame styles can be different even within the same manufacture meaning that when youre upgrading to casements, fixed windows, or French doors there can price difference of 10% to 15% among them.
Thousands of our customers have provided feedback See why our customers selected the manufacturers below by product:
Impact windows: CGI was selected as best for both single hung and horizontal. (PGT bought out CGI in mid-2015 because CGI was gaining ground is sales and CGI provided a nicer looking impact window. CGI is picked over PGT 8 out of 10 times mainly for the cleaner look and because they lock when closed with no sill sticking out and the price is the same.
Fixed Impact Windows: Cosmetically all were close, but when looking at prices ECO and EAS came out on top.
Impact Sliders: CGI holds the spot for single-family homes because they open easily and are less expensive. EAS has a 6000 series which is about 10% less and is still a good choice if you want to save a little money. The main difference is that the track screws do not have covers and can be seen. In condominiums where a higher pressure is needed on any buildings over 50 feet or in Zone 5, EAS has the best price with its 8100 series and overall is one of the nicest looking slider lower steep over sill riser but its cost about 10% to 15% more
Impact French Doors: ECO wins by far in price ,cosmetically, and is the only French door with a five-point locking system ( both doors have two operable handles with 5 bolts as an option priced at $450 each three point $300 more for single door
Impact Casement Windows: All look good, but when price comes in play ECO rises to the top again priced up to 20% less
Energy efficiency hurricane Impact Window would have been more important than ever in South Florida. An update to the Florida Building Code 5 Edition in July 2015 has made significant changes to the hurricane window industry. The code changes were to require more stringent requirements in relation to energy efficiency and specifically new and retrofit window installations.
But all cities in South Florida voted and rejected it mainly because it would cost 30 to 50 percent more to homeowners to have new impact windows installed and it would only increase the energy efficiency by 10%. To be protection for hurricanes is more important than energy efficiency for homeowners in South Florida.
There are two major criteria that needed to be improved to meet the new 2015 Florida Building Code:
The U Factor is a measurement of how much indirect heat transfers through the window and is generally found in a range of 0.25 to 1.25 Btu/h ft F with a lower value indicating a better insulating property. Essentially the lower the U Factor the better the window will perform at keeping the heat out and the cooler air in your home. The 2015 Building Code in Florida now requires a lower U Factor than in years past.
Solar Heat Gain Coefficient (SHGC)
The SHGC is a measurement of how well a window blocks direct heat from the sun. The SHGC is unique in that higher or lower values may be beneficial depending on where you live. For example, in the north, a higher value of SHGC is preferred in order to reduce heating costs in the winter (by letter the sun heat the home). In contrast, here in South Florida, a lower SHGC is preferred in order to reduce the amount of direct heat from the sun in order to reduce cooling costs. The Florida Building Code in 2015 would have required a window to block more direct heat from the sun than past requirements in order to increase energy efficiency.
What Would It Have Meant For Your Impact Window Purchase?
There was a lot of confusion in the industry about these code changes. There are many rumors about cities not enforcing the new code due to the increased building costs, or that the changes may disappear altogether. In order to meet the revised 2015 code as it is written, retrofit window installations now require the use of insulated Low E glass. These are windows that typically contain argon gas in order to reduce the solar heat gain resulting in greater efficiency in Florida. Interestingly enough, aluminum frame windows are still acceptable to meet code requirements in Palm Beach, Broward, and Miami-Dade counties. The bottom line is that it is not required to install insulated Low E hurricane windows with either a vinyl or aluminum frame in order to meet the code. But it may still be a good idea to keep your home a bit cooler and cost you a little less per month in your bills.