Tuesday, June 11, 2019

Guest Article About Energy Efficient Replacement Windows

Guest Author Luis at Enerpro Windows of Denver takes issue with "payback analysis" regarding your new window decision. Welcome and thank you Luis!

Why High-Performance Windows Are Worth Every Penny
Are you a homeowner or someone in the process of building a brand new house? If the answer is yes, then you already know that your windows are one of the primary components of your residence. Not only do you want windows that look nice, but you need those that provide energy efficiency to save you on heating and cooling costs.

There are critics out there that say investing in high-performance windows, that certainly will come with a higher price tag than a lower quality window, isn't worth it. Some have come up with calculations that they feel show that the energy savings over time aren't any more significant than the initial cost of the windows. However, several factors and an entirely different math calculation prove they are what every homeowner should have in their residence. Those living in unusually cold climates are likely to see the biggest savings. Even if you don't live in a northern region, discover how a new set of high-performance windows will pay for themselves over the time you live on your property.

Understanding Your Home's Energy Use and Efficiency

Every home, whether existing or a new build, is going to have an R-value. Frequently the roof, walls, and slab all have varying R-values depending on the materials used. The higher your R-value, the better the insulation of the structure. When your property has a decent R-value, it's a sturdy construction with minimal airflow. The less air going in and out of your home, the less often your heating and cooling systems have to work. As a result, you're saving money on energy costs.

You can add to your R-value by adding in insulation to the basement, attic, or walls. You can also add to your R-value by putting in new energy efficient windows. Depending on the work you do, you could be eligible for a federal tax credit. Already, before you've even explored high-performance windows, you have the potential to make money back on your home improvements.

Checking the U-Factor in New High-Performance Windows
To ensure your new window installation is going to improve your R-value, you have to understand the U-factor. Every window that comes from the manufacturer comes with a U-factor sticker on it.

Take note: If you're working with a professional window contractor and they rip the sticker off before you can see it, you should be suspicious of what they're covering up.

The U-factor tells the consumer how much heat is lost through the window after it has been correctly assembled and installed. The lower the number, the higher the insulation properties. For the best insulation, you should look for a window that has a 0.40 U-factor rating or less. If it doesn't, then you aren't purchasing high-performance windows and you aren't going to see much if any in your energy savings. What you're going to see on your U-factor sticker includes:

  • Resistance to heat flow - non-solar heat flow
  • Solar heat gain coefficient (SHGC) - sunlight hitting the window and penetrating the home
  • Air leakage - expressed in cubic feet per minute the amount of air that goes in and out of the window when properly installed

Check these numbers carefully, or have a trusted contractor do it for you. Shop around for Low-E coatings that improve the U-factor. Some have higher SHGC which are more beneficial in colder climates.

Doing the Math on Energy-Efficient Windows
After doing the calculations and determining that new energy efficient windows will improve your R-value, then you know that you will be saving at least some money on heating and cooling costs. That's where the debate begins. Is what you're going to control in energy worth the initial cost of the windows?

Think about it this way: If you get a loan for $3,000 at 5% interest and you add that onto your home mortgage payments, you're going to be paying an additional $195 annually. When you're saving anything over $195 a year on energy costs, you're already on your way to a payback of your initial investment.

The actual savings that you're going to see depends somewhat on where you live. The type of windows that you're replacing will also have an impact on your savings. The experts at Energy Star say that in a typical home, replacing single-pane windows with higher performance ones will save homeowners anywhere from $126 to $465 each year. If math isn't your strong suit and you're working with a reputable window installation company, they will be able to show you your exact figures before you invest. More often than not, it's going to result in at least some savings.

Other Factors to Consider When Calculating Savings
Besides what the gains are right now, there are other factors to keep in mind when deciding on high-performance windows.

Remaining Comfortable Throughout the Entire Home All Year

Have you ever sat in front of an old window during a snow storm? If you have, then you know just how uncomfortable that can be. The wind whips in and out, almost like there isn't even a window there. That means, any part of your living space in front of a window is going to be abandoned for part of the year, or you'll be purchasing additional heating equipment to keep that particular space warm. You can't necessarily put a price tag on the square footage of space you're losing in the winter, but at the very least it's an inconvenience to you and your family.

Energy Efficiency Remains in Place During Power Outages
In the event the power goes out at your home, either in the winter or the summer, the air is instantly going to start escaping through every crack and crevice in the structure. With high-performance, energy-efficient windows, you'll be able to maintain the temperature for a much lengthier period. When the power does come back on, your heating and cooling systems won't have to work quite as hard to catch up, therefore saving you money again. Not to mention the peace of mind knowing you and your family can stay put and comfortable in extreme weather conditions.

Potential for Frost
If you've ever spent any amount of time in home or business with drafty windows in the winter, you've likely seen the frost buildup on the inside. Frost creates an entirely new set of issues. Not only does it make the home chillier and cause you more work cleaning it up, but when it melts and drips, it can stain materials around the window or even lead to harmful mold growth.

Rising Fuel Prices Are Always A Possibility
Looking back at the calculations from Energy Star on the savings for high-performance window installations, you have to keep in mind that they are using the current energy and fuel prices. You can pretty much guarantee that these numbers will continually rise over the years. However, your initial cost on your windows will remain the same, because it's already been paid. Therefore, your overall savings will increase with the rising prices for heating and cooling.

Attachments for High-Performance Windows Add Thermal Resistance
Many models of high-performance windows have attachments that can be added on for even more thermal resistance like shades, quilts, and Low-E storm windows for winter. Not only do the accessories give you a lower U-factor and higher R-value, but you also gain additional benefits like controlling the glare on sunny days, increasing privacy, and even getting solar energy, depending on what you use.

Lower Your Cost with the Style of Window You Use
When considering high-performance energy-efficient window replacements, take into account what style of window you want to use. Stationary windows, for example, are significantly less expensive than a double hung, awning, or casement window.

For homeowners that are building from the ground up, you should contemplate using more big windows and fewer small windows. Just because the window is bigger doesn't mean that it's necessarily more expensive. With fewer window cutouts in your home, there are fewer opportunities for air flow from the inside to the outside and vice versa. Whatever style you choose, be sure it has an insulated frame as well for even more energy efficiency.

Hire a Trusted Window Installation Contractor!
Nightmare stories about dishonest window installation contractors are out there, and that makes most consumers nervous about hiring someone. While not all window companies are the same, some will quote a price and promise a particular product. Then, they will order and use a cheaper product to increase their profit margin. When it happens, it's fraud, and it can leave homeowners unwilling to trust another home improvement expert. You also won't see the changes in your energy savings if they promise a particularly high-performance window and then install something of lower quality.

Before deciding on any window installation contractor for your new high-energy windows, do your research to ensure you are selecting a reliable one. Check their licenses and insurance, years of experience, and previous customer reviews. Explore several options and get a few quotes before settling on one. The last thing you want to do is pay for high-performance windows and receive something less. As long as you take the proper precautions, you shouldn't have any issues with your home improvement specialists.

Saturday, July 15, 2017

Super Quick Payback Now Possible with LED light bulbs

In a previous article, we showed that an average LED bulb will save $10.69/yr.

I just bought dimmable A19 bulbs at ACE Hardware for $0.99 each.   Even if I use this lighting half as much as the estimate, the payback period is under 3 months.

Here's a link to finding those 99 cent bulbs


Thursday, August 18, 2016

Solar Power Now Worth up to Triple the Cost of Grid Power in CO

This is big news for photovoltaic solar customers in Colorado.

I first proposed this in 2007.  Xcel then tried Smart Grid City which they bungled.

Xcel is finally letting us benefit from the advantages of:


"Net Metering Time of Use (TOU)
COSEIA and other solar parties scored a win with the agreement that  extra energy generated by solar systems in a given month can be rolled over as a monetary credit that recognizes the value of the energy at the time it was generated. The credit will be used to offset the bill for consumption the next month and can continually roll over. Those who have elected to cash out extra production will still have that option. "

(From a COSEIA email announcement of the settlement)

Time Periods:
On Peak:       2 PM through 6 PM (weekday, non-holiday)
Off Peak:       9 PM through 9 AM
Shoulder:      All Other Hours

Price per kilowatt-hour (kwh): 
                                Summer                     Winter
On Peak:                  $0.13814                   $0.08880
Shoulder:                 $0.08420                   $0.05413
Off Peak:                  $0.04440                   $0.04440

For example, if your PV system generates 10 kwh between 2 pm and 6 pm, Xcel must give you a credit of $1.38.
But if you can use the same 10 kwh during off peak hours, it will only cost you $0.44.

Some of the takeaways:

1.  Solar systems will earn more money if they face to the southwest instead of due south.
2.  Homes in Colorado can now benefit from smart timers and products like the Tesla Powerwall.
3.  The demand peak for power occurs at 4pm, which doesn't align with peak solar production. Battery storage is the key to solving this problem, hence the Gigafactory and V2G.

Note that there are a bunch of fees and charges on your utility bill that make it difficult to see your actual cost per kwh.  This issue killed TOU rates the first and second time around.


Thursday, June 16, 2016

Now You Can Affordably Tell if the Air in Your House is Healthy

Nate Adams has tested some of the affordable consumer grade indoor air quality (IAQ) monitors:
http://energysmartohio.com/blog/which-indoor-air-quality-monitors-are-best-and-why

UDATE:  I bought the Foobot, and it will go into our new homes to see if the initial air quality is acceptable. 

With all the new materials and paint, etc., the initial air quality can be suspect.

Monday, June 6, 2016

Low Energy Carriage House Under Construction

After a painfully long permitting process, GBID's "Tandem House" at 2268 S Acoma (off the alley) is under construction.

Design Highlights:


1.  Double stud "Shirley Wall" construction to meet superinsulation goals.


2.  Insulated forms for stem walls.


3.  No natural gas needed for the house.


4.  Heated and cooled with one ductless minisplit heat pump.


5.  Passivhaus air tightness goal, (0.6 ACH 50)


6.  Fluid-applied Vapor Permeable Air Barrier.


7.  Grid tied PV system for net zero yearly energy usage.


8.  Induction range for cooking.


9.  Ductless heat recovery ventilator.


10. Ventless heat pump clothes dryer.


11. Complies with Denver's new Tandem House zoning form.  The home can be legally sold seperately from the home in front.






Sunday, May 8, 2016

Tiny Houses and Sustainability

A new study is out on the topic of tiny house feasibility for urban settings.

Tiny Houses could be a large part of the solution to affordable housing in Denver.

Here at GBID we are continuing to gain experience in the low cost housing sector by renting out fiberglass egg trailers parked in back yards.  These trailers have full utility hookups.

We just rented another one for $450/month after a tenant moved out.  Here's a one-minute "exit interview" with Dave after his 6 month stay in the Scamp.   https://www.youtube.com/watch?v=bvH-ufaR4u4

This price point makes it one of the few solutions for someone trying to survive on minimum wage or Social Security alone.

Sunday, April 10, 2016

LED Lighting is evolving quickly

Conturrent puts low energy LED lighting into a less expensive total package.

This is starting to deliver on LED's potential to deliver a lower first cost as well as using a fraction of the electricity of older systems.

"Conturrent uses so little energy that it doesn't need all the protective hardware of traditional lighting systems to keep you safe from dangerous (110v) AC voltage."