Monthly Archives: April 2014

Carbon Monoxide and Your Garage

I am studying ‘The Residential Ventilation Handbook’ by Paul Raymer. Mr Raymer has worked with residential ventilation, design, consulting, teaching for over 30 years.

I just reached the Chapter on Garages. I’ve known for several years the potential problems with an attached garage. Two years ago, I did some recommended work in my garage because of these issues. I carefully sealed the wall between the garage and the house, and I installed a mechanical ventilation fan.

lawnChemWhy is the attached garage important to the Indoor Air Quality in your home? OK! What is in your garage? Mostly stuff you don’t want in the house. Like fertilizer, bug spray, weed killer, gas for the lawn mower. Cars, and other vehicles are usually there also.

Mr Raymer includes a table of Carbon Monoxide levels and comments or the potential for harm to people. I knew some of these, and others I did not. Carbon Monoxide is a colorless, odorless gas that is a byproduct of burning fossil fuels, like gasoline, natural gas, or propane. Carbon Monoxide (CO) is measured in parts per million (PPM)

Here are some entries from the table:

1-2 PPM Normal from gas range, traffic etc.

9 PPM Maximum Allowable Level for 8 hour period in any 12 month period. EPA and ASHRAE. Normal after using an unvented gas oven.

15 – 20 PPM Impaired performance in time discrimination and shorted time to angina response

30 PPM UL standard that detectors not sound an alarm unless exposure is continuous for 30 days.

35 PPM Maximum allowable outdoor concentration for any one-hour period within a 12 month period. EPA – ASHRAE

50 PPM Maximum allowable 8 hour work exposure (OSHA)

150 PPM UL Listed detectors must sound full alarm between 10 – 50 minutes of exposure.

500 PPM Car started from cold in garage with door open, and allowed to run for two minutes

800 PPM Dizziness, nausea, and convulsions within 45 minutes.

6400 PPM Death in 10 – 15 minutes

70,000 PPM Typical tailpipe exhaust concentrations after cold start during the first minute the engine runs.

NOTE: After running for 17 minutes, these concentrations finally drop to 2 PPM

tailpipeI think the above table is worth serious consideration from every home owner, every father and every mother.

Flags: The First of the Flowers to Come Inside!

Flowers are nice. They indicate that spring is here, winter is over and we can spend more time outside.  The birds chirp, the bees buzz around and the colors are wonderful.  I have memories as a child of flower gardens and ponds in them.  I don’t remember much detail, except they were always fun.

We moved to the Southern Nevada Desert early on.  I lived there until I left for college.  I went back east from Nevada to Kansas.  My flower journey has me getting married and joining into my wife’s Kansas family traditions.  The flower tradition is rooted in Decoration Day.

  Known to most as Memorial Day, I learned Decoration Day.  My wife’s folks were quiet farm types.  They had many opinions, and occasionally would even state them.  Most of the time they listened.  They remembered that God gave us two ears and one mouth.  I  have to continually remind myself of that. They taught me all about Decoration Day, by doing, not by talking.

It was a day to visit the various cemeteries and the graves of family members. You made sure the grave stone and appearance was acceptable.  You didn’t wait until the actual Memorial Day. I started this when Memorial Day was May 30; not always on a Monday. That came later. You started the weekend before Memorial Day.  The goal was to make sure when the ceremony started on the Memorial Day, or those from out of town came to visit the cemetery, you graves looked good.

In the yard around the house, my Mother-in-Law, Eda (Roberts) Greenfield, had lots of flowers.  She had a green thumb, and could keep her African Violets blooming year round. In the first years as I learned about Decoration Day, she would have a number of jars ready. Jelly, mayo, etc. Ready meant cleaned out and covered with aluminum foil.  Final preparation was to cut flowers from the farm yard and put them in the containers in water.

Then off we went.  They would go to two different cemeteries. There was the Princeton, KS Cemetery. This is where the Roberts side of the family was buried.  Her folks, and grandparents, and others.  Then we went the other way, to the Williamsburg, KS cemetery. There were the Greenfield family members. Parents and others, including their baby son.

In time, we added more cemeteries. Last year, my wife and I visited 7 cemeteries. Three of those have been added to our list from my start, because life goes on and ends. So people I knew were buried, it was not just about people that I had heard stories about.

One of the cemeteries we added, was my father-in-law’s mother. Glenn was born in 1907, his mother, Myrtle Irene Lightle, died in childbirth in 1917.  She is buried in Hall’s Summit, KS Cemetery.  If you find the intersection of I-35 and US 75, (BETO Junction) south of Topeka, you are close. It is actually 5 ½ south on US 75, then 3 East and ½ south. You will see the ATT Long Lines tower before you get off 75.  My brother-in-law, Paul would not find it that way.  He is a Geologist by training and works for the Nuclear Regulatory Commission.  He would tell you how far is is from the Wolf Creek Power Plant. (About the same as from BETO junction.)

This grave had a large plot of flowers growing behind the grave stone. Perhaps a circle 20 feet in diameter. The few that were blooming were a pale yellow. They were Iris.

Eda always liked these ‘Flags’ as she called the Iris.  This cemetery had a number of graves with Flags planted nearby.  Both entrances to the  cemetery were marked with plantings of Flags.  Through the next few years as we drove in and out different ways, we found the country roads were spotted with Flags growing in fence lines, hedgerows and farm yards.

We could see them on this weekend before Memorial Day because they were in bloom.  All the bright Yellow, Purple, and mixed colors were there.  Watching them over the years gave me an appreciation for them.

Each year at Halls Summit, we would remove a few from that large circle. As we did so, more would bloom the next year.  Some years just one or two Rhizomes, some years we might get 30. Last year the circle was closer to 10 feet in diameter.  Those Flags have populated a lot of places. We just didn’t throw them away. They went to churchs, yards, a school that I can think of.  One Boy Scout used them in his Eagle Project.  I’m sure some of those have been thinned and have moved on.

So when I think of flowers, I think of Flags. I think of Road Trips, cemeteries and family.

– – –

I am reposting this post from my old blog.  I picked the first batch of my flags to bring inside, after dinner.

What Types of Buildings Does a HERS Rater Work On?

I had an question last week.  ‘What types of homes can you put a HERS Rating on?”  A second question came along with it, “What types of buildings can you certify as Energy Star?”

These are great questions!  We usually think of homes as being a house in a subdivision or older neighborhood. It usually houses one family.  These are referred to in the trade as ‘Single Family Homes’.  Not everyone lives in one of these.  There are duplexes, four-plexes and all sorts of high rise apartment houses.  These are referred to as ‘Multi-Family Housing’. There are also buildings that have retail shops or other non-residential areas, with living units on the upper floors. These are referred to as ‘Mixed Occupancy’.

A HERS Rating is applied only to residential units. The ‘Home Energy Rating System’ was developed by the Residential Energy Network, commonly called RESNET. This non-profit organization provides guidelines for training, maintains the standards for the HERS Rating process, certifies the software used to IRS Standards, and finally enforces a Quality Assurance Program on all Ratings issued.

There is an organization that is developing a similar set up for commercial structures called COMNET.

The HERS Rating results in a score on the HERS Index. This score can be used by home buyers, realtors, appraisers, and many others in the property sale transaction. This rating is a private transaction usually between a HERS Rater and the property owner. Many HERS Index Scores are specifically used to market a property.  A HERS Rating may be completed for a new or an existing home. Lenders in some cases are requiring HERS Rating.

The HERS standard does not specify any specific products, methods or other requirements. The resulting Index Score reflects different levels of energy efficiency between rated homes.  A home with a higher score will use more energy than a home with a lower score. The index starts at Zero and goes up.  The highest score I have personally completed was 384.  Most existing homes score between 95 and 150.

A HERS Rating can be completed for single family or multi-family homes. The limitation applies to buildings that are 3 stores or less. In the trade these are referred to as ‘Low Rise Residential buildings.

Energy Star is a Brand that is promoted by the Federal Government since 1992.  It is designed to designate the top 20% of a product line with the most energy efficient features built in.  Every product line has standards for energy use. Specific tests are required on the different products.

Refrigerators are a great example.  A 25 cubic foot refrigerator is only compared to similar size units. A 10 cubic foot unit designed for a smaller apartment is not compared to larger units. there are a large number of refrigerator classes available.

Some products do not have an Energy Star qualifying standard.  Examples here would include clothes dryers and ranges, ovens and cook tops.

Energy Star Homes use a set of mandatory requirements that must be followed and a HERS Rating that must be earned. The requirements are detailed, covering 7 pages of checklists. They require specific energy related items, for example, continuous insulation. They also require things such as flashing of windows and doors for durability. It makes little sense to build an energy efficiency home that would allow water to enter the wall and destroy the insulation.

A maximum HERS Index score  is set, based on the size and number of bedrooms of a home.

Commercial buildings also qualify for an Energy Star Rating. Existing building qualify by reducing energy usage. This process, like most Energy Star certifications, is voluntary and as a HERS Rater and Thermographer, I am qualified to assist with, or to complete.

New commercial buildings qualify for Energy Star, by design and verification of the actual design being present in the completed building.  I can help with this also. Since most of these buildings have architects and other professional engineers involved in the planning, my role is more in the verification process. In the commercial area this process is called Building Commissioning. I would work primarily with the Thermal Enclosure and some of the HVAC issues.

Common Approaches to Heating Your Home: Part III

This is Part III of a 3 part Series.  Part 1 is here; Part 2 is here.

Hybrid Heat Pump

This choice is sometimes referred to as a Dual Fuel Heat Pump. It utilized both gas and electricity to heat your home. The efficiency of a heat pump is because at most heating temperatures, it moves heat from outside to inside.

Think about your refrigerator. When the inside warms up to 40•, the food risks going bad, so the fridge finds the heat and pumps in out.  Your food stays refrigerated. At 40• outside, a heat pump can find heat and efficiently bring it inside. This costs less than consuming natural gas, propane or electricity to produce heat in a furnace.

At much lower temperatures, a heat pump will need a boost to maintain the heat. This is an electric resistance strip heater. It is used in emergency and back up situations.

A hybrid heat pump uses a conventional furnace for emergency and back up. This is less expensive than electric resistance heat.

Your Choice

In our climate zone; I believe the rank of these approaches should be:

  1. Geothermal
  2. Hybrid Heat Pump
  3. Traditional Furnace / AC
  4. Air Source Heat Pump

This ranking is based primarily on Efficiency Issues with overall comfort issues second.  This rank considers only long term operating costs. It does not consider capital costs (installation).

There are two primary considerations for all of the installation and ultimately comfort issues.

  • The home must be ready for an efficient heating/ac equipment installation.  This means the thermal envelope must be sealed and well insulated. Your thermal envelope is defined as the basement walls, or crawl space walls, the wall above ground, the ceiling.
  • The calculations for equipment size, and selection must be done professionally. The use of a recognized computer program authorized by the ACCA (Air Conditioning Contractors of America); showing the Manual J calculations of the improved home for determining heat loads; and the Manual S calculations to select the equipment. You may wish to have your ductwork reviewed and perhaps resized.  This would call for calculations with ACCA Manual D.

The choice to go with Geothermal or ASHP would mean very little gas usage, only the hot water heater. That could be converted to electric with the ASHP. With a Geothermal Unit, you could utilize a system of hot water that is known as ‘de-superheating’.  It uses otherwise wasted heat from the Heat Pump unit to heat water.

The capital costs of these units in the Wichita area are estimated at:

  • Geothermal:               15-25,000+ (open or closed loop)
  • ASHP:                           7 -12,000
  • Hybrid Heat Pump:    7 – 12,000
  • Furnace/AC                 7 -12,000

The Geothermal unit is considered to be a renewable energy source and carries a 30% tax credit, with no limit.  It is available through 2016. Before giving much thought to a geothermal system, a homeowner should discuss the location with a driller to determine the depth of wells and the quality of the water. Do not install an open loop (also known as pump and dump) without a water quality test in your possession. Consider a closed loop system, if there are any concerns about water quality or the amount of water needed. Drought is a reality in Kansas. A well designed and installed geothermal system will last many years.  I have audited homes with systems that are 30+ years old. I have audited homes with failed systems, of 10 years or less, that were not well planned.

Comfort Note: Conventional Furnaces blow heated air into the duct work at temperatures from 105 – 150; depending and the design factors of the furnace.  If you have come in from the cold and stood neat the supply register of a forced air furnace, you feel the heat.  A heat pump type of heating does not create heat to be blown into the duct work at these high temperatures, a heat pump typically blows air into the ducts at 85 – 95 degrees.  This change can cause people to not like a heat pump; air source or ground source. A hybrid heat pump would provide the same range as a furnace with lower outside temperatures.

Please post your questions below as comments!

Common Approaches to Heating and Cooling Your Home: Part II

The Traditional Furnace and Air Conditioner Approach

Part I of this article can be found here.

The traditional furnace burns fossil fuel, either electricity or gas to create heat. The air conditioner is a one way heat pump. Air conditioners are almost exclusively powered by electricity today. It has not been that long since there were many gas powered air conditioners and refrigerators. Burning fossil fuel; either coal or natural gas is the primary source of electricity in Kansas. Less than 10% of our power is nuclear or wind generated, as of 2010.

The efficiency loss of a gas furnace can be as much as 50 percent of the heat literally going up the chimney. The most efficient gas furnaces are sealed combustion types. They utilize a condensing flue to achieve an extremely high efficiency. These units usually do not have a chimney through the roof. They exhaust out the wall near the ground. The temperatures are low enough, to allow plastic flue piping.

Their efficiency rates from 92 – 95 percent. In 2011, the Federal Income Tax Credit allowed home owners that purchase a 95 AFUE condensing furnace. An added feature of these furnaces is the sealed combustion chamber. They require no make up air from inside the home, and they cannot back draft deadly flue gasses into the home.

Electric furnaces are generally considered to be 100% efficient in the home. The electrical transmission system, does see a loss that amounts to about 35%. The generator burning fossil fuel also has less than 100% efficiency.

Air conditioners, available at this time, at a minimum are rated at 13 SEER. Most existing units vary from 6 – 11 SEER. You can purchase units with a rating of 18 – 20 SEER. A rating 15 SEER is the most common available High Efficiency Unit. Some manufacturers have a 14.5 SEER that is certified to use less power than a 16 SEER unit.

CompressorWhat is that trick? It is not a trick, but is part of the tool kit available for selling heating and ac units. An air conditioner consists of two parts. The outside unit, referred to as the compressor or the condenser, and the inside unit referred to as the evaporator. These must be matched correctly each other and the furnace (the blower fan is there) to achieve a specified SEER Rating. SEER is Seasonal Energy Efficiency Ratio.

For a user friendly description on the magic of Air Conditioning, a link to Energy Vanguard’s Blog Post on the subject.

The American Heating and Refrigeration Institute (AHRI) certifies furnaces, and air conditioners. Here are 3 entries with the same condenser/evaporator match with different furnaces.

AHRI Number      Model No Cond.        Model No Evap        Furn No              SEER

4137591                 24ABC630A**30       CNPV*3621A**        58HDV040–12        15

3630546               24ABC630A**30       CNPV*3621A**       58CV(A-X)090-16    16

3630606              24ABC639A**30        CNPV*3621A**       58CV(A-X)0110-16  15.5

As you can see here are 3 different furnace units partnered with the same outdoor unit and indoor coil. They are rated for different efficiency levels.

If you would like to look up your units, the information is on the data plates. You need the model numbers.

  • The evaporator coil plate is on the inside unit, usually the easiest to find. The evaporator will be either above or below the furnace, appearing to be in the ductwork.
  • The condenser unit is on the outside unit, usually it is on the side by the copper tubing. The furnace data plate is usually found in the burner compartment of the furnace.
  • If you have the original paperwork for your units, the model numbers may be there. After collecting these numbers go to AHRI Directory

If you are buying a new HVAC system, ask your contractor for the AHRI certification numbers and look up for your self, the efficiency ratings.  Unfortunately I have seen many new systems the Home Owner was told is a High Efficiency Unit, only to find the matching process did not meet the Sales Hype!  If you would like some help in this process, The Energy Guy can help. Contact me for details.

For Part III

Common Approaches to Heating and Cooling Your Home Part 1

Homes in Kansas are heated by several methods. These range from wood stoves to various types of solar heating.  The most common method is a central forced air unit. These are found both as a sole method and sometimes in combination with other methods.

Forced Air Heating and Air Conditioning

Forced Air units have several things in common. Duct work to distribute the conditioned air to various parts of the house; a blower fan, known as an air handler; and a source of hot air and a source of conditioned air.

FurnaceTraditionally, the warm is created by burning a fossil fuel, either electricity or a gas (natural gas or propane). The cool conditioned air is created with an electric compressor and outside condenser coil with an evaporator coil in the plenum.  These relatively common units have been updated in terms of efficiency over the years.

During the past 20 years homes are starting to use one or another type of heat pump to do the work of these units.  Moving heat is more efficient than burning a fossil fuel to create heat.  All homes have one or more heat pumps; these are known as a refrigerator or freezer.

Instead of converting energy in the form of gas or electricity to heat by burning a fossil fuel, as a furnace does; the heat pump uses electrical energy to move heat. It moves the heat in or out of your home.

Air Source Heat Pumps are the most common heat pumps found in homes today.  This can be an efficient way to heat and cool your home. ASHPs are more common south of Wichita than north, since they are not as efficient in cold weather.  The other type of heat pump that has been gaining in popularity  is the Geothermal Heat Pump. The cost to install a Geothermal system is dropping.  Geothermal uses heat from the Ground and is more properly referred to as a Ground Source Heat Pump.

The Geothermal Approach to Heating and Cooling Your Home

Geothermal is the popular name for a Heat Pump using a Ground Source for heat transfer.  During times when the air outside your home is cooler than you choose to have your home, this heat pump transfers heat from the ground, below the frost line, into your home.  During times when the air outside your home is warmer than you choose to have your home, this heat pump transfers heat from your home, into the ground, below the frost line.

What is the temperature of the ground, below the frost line?  It is very close to the average annual temperature of your area. In Wichita, that is about 54° F.

A Ground Source Heat Pump, can be very efficient, because it transfers energy.  It does not convert energy from electricity or gas to heat.  In the winter, it moves heat from the 55 degree source to warm your house.  In the summer it discharges the heat removed from your home into the 55 degree source.

The Traditional Heat Pump Approach

An Air Source Heat Pump transfers heat to and from the air outside your home. During times when the air outside your home is cooler than you choose to have your home, this heat pump transfers heat from the outside air into your home.  During times when the air outside your home is warmer than you choose to have your home, this heat pump transfers heat from your home, to the air outside.

The ASHP is an air conditioner with a reversing valve for winter usage. There are some small technical differences. You can use this concept to understand how it works.

This approach works great and yields great efficiency when the temperatures vary outside between  a low of 40 and a high of 80. In climates with lower or higher temperatures the ASHP has to work much harder to find heat in 20 degree or lower air outside in the winter to heat your home. These units are usually set up with electrical resistance heating for lower temperatures. This can be expensive.  In the summer the ASHP is trying to discharge heat from your home to a much warmer outside, this reduces the efficiency.

These disadvantages cause some people to bypass the ASHP.  Others have had bad experiences with some of the early units.  They have improved over the last few years and make a strong showing.

This is Part I of a III Part Article.  Here is Part II

The Energy Guy Opens for Business

Derby Chamber LogoThe April Derby Chamber Newsletter published this announcement. Thank You, Mark Staats, and the staff, and for your help and support over the years.

John Nicholas has rebranded from Efficient Energy Savers to the Energy Guy! His services include: Home Energy Audits for existing homes, HERS Ratings for new home construction, Infrared Imaging for both Residential and Commercial markets, and certification of Energy Star for new residential construction. He can still be reached at 641-5258 or his new website, 

Earth Day 2014

Everyone seems to have something good to accomplish on Earth Day this year.  Twitter and Facebook have had regular comments all day. Energy Star had a Tweet Up going online with people from all over the country.  GE donated some LED lamps for a give away.  So to get in the spirit, here is what I  accomplished.

image001Wichita Habitat for Humanity builds Energy Star new homes.  One of the requirements is to limit duct leakage, by strictly following Wichita City Code and all manufacturers instructions for materials.  The professional standard established by the Air Conditioning Contractors nationwide is 6% of system air flow. Energy Star requires 6 cfm (or less) of leakage with a duct pressure test for each 100 square feet of floor area.  This home tested at 50% of the Energy Star Requirement.  The system tested at 5% of system airflow.  Great work!  The mechanical contractor on this house is Cook’s HVAC of Wichita.

BDThis afternoon, I did a Blower Door Test. This test measures the energy loss due to infiltration.  This again, was new construction and the first HERS Rated Home in Wichita for the season. Wichita / Sedgwick County have not adopted the Energy code. If they were enforcing the 2009 version, this home would have exceeded the requirement by almost 50%. It is 20% above the requirement for an Energy Star New home.  Great Work! This shout out goes to a number of contractors.

1 Inch HoleAir Sealing has many pieces.  Framers, electricians, plumbers can all cause many problems for this test.  So when they cooperate to help achieve the end result, it is a good thing. Fibrous insulation (Rockwood, Fiberglas, Cellulose), by itself does not effect infiltration. Air will move through all of them. The insulators must install the insulation correctly. They must caulk many places. I observed much of this during my pre-drywall inspection.

IMG_6793I am sure Wade will pipe in here for a comment and a shout out for these subcontractors.  Wade Wilkinson is principal of GJ Gardner Homes of Wichita.  This home will be their entry in the Wichita Area Builders Association’s Spring Parade of Homes. You can read my Post on the WABA Parade of Homes




Verifying good workmanship by builders and contractors is a great part of being a HERS Rater.  What did you do for Earth Day?

Dr. Mario Medina, PE of KU appointed to the RESNET Training and Education Committee

This is a point of Pride for Kansas, having a member of the KU faculty appointed to the Education Committee of RESNET.  His experience with Energy Modeling will be of great value.

As the HERS Index becomes the standard by which new homes across the nation are provided with a Transparent measure of the quality built into them by the builder and the subcontractors; the Training and Education Committee becomes more and more important. Important to home buyers, home builders and HERS Raters.

Below is the RESNET Press Release, compliments of Steve Baden the Executive Director.



Dr. Mario Medina of the University of Kansas has been appointed to the RESNET Training and Education Committee.

Dr. Medina is associate professor in the Civil, Environmental, and Architectural Engineering Department at the University of Kansas.  He also has an appointment in the Mechanical Engineering Department.  He joined the faculty in 1998.  Dr. Medina holds a Ph.D. in mechanical engineering with a specialization in building physics.  He has extensive experience in the modeling and experimentation of building enclosure systems.  His research involves the development and experimental verification of thermodynamic and heat transfer models used to study building energy dynamics as a result of enhanced insulation systems and the thermal performance of building mechanical systems.  He has published over 70 technical articles in the area of building energy efficiency alone.  He has written over 100 reports detailing energy conservation procedures from assessments in industrial manufacturing plants.  He received an “Outstanding Service Award” from the Office of Industrial Technologies of the US DOE for work related to promoting energy conservation. Dr. Medina has been involved in the experimentation and simulation of the performance of insulation systems since the late 1980’s.

Dr. Medina’s focus on the committee will to draw the design committee into RESNET through the development of training and designation opportunities.

The RESNET Training and Education Committee is responsible for issuing interpretations on Chapter Two of the national rating standards, maintenance of the national rater test, approval of all RESNET education programs, and maintenance of RESNET rater certification categories.  For more information on the committee go to RESNET Training and Education Committee

© 2014   RESNET

Residential Energy Services Network


Features Most Likely to Show up in Typical Single-family Home in 2014

The National Association of Home Builders has a great research department.  I’ve learned a lot about building technology and marketing from some of their reports. They published another one today.

You can see the original on NAHB. 

Guess what The Energy Guy picked up on?  Only one guess now!

Features 2014


Five of the 18 items relate to Energy Efficiency. That is 27%.  One more study that shows the importance of Energy Efficiency to Home Buyers. The article is fairly clear there are many more features surveyed that ranked below this, these are the features a builder needs to provide and point out.

The last one lists ‘Insulation higher than required by code’  –  Since Wichita/Sedgwick County has not adopted an Energy Code this is up for grabs.  Until last year the recommended code for Attic insulation was R-38.  Most builders in the area only install R-30 or even less.  I’ve had several builders tell me they put R-38 in the attic and when I get to the attic, I see the Insulation Company’s Attic Card showing R-30.  One reason that Independent 3rd party Verification is important.  This is an important part of a HERS Index on a new home. The current code recommends R-49 in the attic. As energy prices go up, it makes more sense to have additional insulation.

There are two window items of interest.  First is the desire for Low E  windows.  This is a type of coating on 1 side of one of the panes of a double or triple pane window.  Which side and which pane it is on is very important.  On the wrong pane, the window is designed for Brownsville, TX not Wichita, KS.

Second is the desire for Energy Star certified windows.   Window requirements change with the climate.  If you are in Minnesota, your weather requires a different window specifications than the weather in Kansas. Keep in mind, that Oklahoma is a different climate for certification than Kansas.  I have found a number of new homes in Wichita, that are built with Energy Star windows, if you are in Oklahoma.Climate zones

Finally,  a Lo-E coating on the window helps in the summer time with solar heat gain.  Lo-E is part of the recipe for building a window. Residential windows are certified to Independent Standards and should carry an NFRC Sticker.  Again, checking the NFRC sticker for specifications is part of the Independent Third Party Verification that is part of the HERS Index.

Ask to see the HERS Rating on all new homes you look at.  If there is not a HERS Index, ask the Builder to place a rating on their work.