Category Archives: Air Conditioning

What Happens After You Finish Your Part of the house, and Then The House Is Finished?

images-2Modern home building takes a lot of people. Concrete, Carpentry, Heating and Air, Paint, Drywall, Insulation, Electrical, Plumbing and many others. These professionals work on the house at various times. Usually there is a sequence, the foundation is done before the framing, the roof is done before inside work gets very far. Toward the end, it can get somewhat hectic. Everyone is trying to finish. The deadline is looming. Painters, trim carpentry, flooring, plumbing, final electrical installations are all happening.

One of the last things is the final work on the Heating and Air Conditioning system. This cannot happen until after the electrician is finished, and if you have a gas furnace, the plumbing must be there. Some of the work by the HVAC contractor was completed before the drywall went up. The duct work was installed and the inside unit of the system was probably put in place and hooked up to the duct work.

If the home is built on a 120 – 150 day schedule, the initial work, rough-in, on the duct system would happen about 1/3 of the way. Then about 2/3 of the waywall_duct, the Heating and Air techs are back to install the thermostat, the outside unit, hook up the electric and finish the job.

Last week, I went out to complete a rating on a new home. I had completed some testing on the duct system at rough-in. I used a Duct Blaster unit and testing the duct system for Total Leakage. I got a great number. There is a professional standard, issued ACCA (Air Conditioning Contractors of America) for this test. It is based on the size of the amount of air flow pushed through the system by the fan; in this case it would have been about 1,200 cubic feet per minute.

The standard is 10% of system air flow or in this case 120 CFM. In a previous blog post, I discussed a test where the system leaked over 100% of system air flow. This is an important test, because it can be compared to the test done at rough in.ACCA_5

The rough in test for Total Duct Leakage came in at 4.8% of system air flow. This is a very good number and typical for this HVAC contractor. Now at final, the total leakage was 16%. Wow! What happened?

I cleaned up and left the house about 6:00 for the weekend. Sleeping on the ‘What Happened?’ seemed like a great idea. I did just that.

Tuesday, I went back to take another look. I would conduct some additional testing to see if the leak(s) could be isolated. I started by removing the grills that fan the air out through each room. That would be easy and fast. So, the first few looked pretty good. It was going fast, I kept going and half way through I found one that showed some problems. At the end 1/3 of these grills had a significant problem.

Duct BootAs you can see the vent in the wall, had the drywall cut too large for the duct. The openings ranged from a quarter inch to over an inch wide, all around the opening. The air instead of 100% leaving the duct system into the room, was being pushed back into the wall. The idea of the duct system is to put the hot or cooled/dehumidified air into the room where the people are. A grill can do a great job of sending the air into various parts of the room. A good grill for one place may be absolutely the wrong grill for another place. Grill manufacturers refer to this as ‘Throw’. If you have the wrong throw on your grill, you aren’t getting much comfort from your system.

The infrared image, below, shows the outside of a wall in the winter (It was 20° F that morning). The hot area below the window is from the grill directing the heat up the wall, not out into the room. I found this condition on an audit last winter and made two alternate recommendations for the home owner. The cost was less than $20.00 for either one. The problem was fixed the same day by the homeowner.exterior_wall

Back to fixing the leaks! I filled the cracks and gaps in the poorly cut openings, replaced the grills and then set up to re-test the duct system. The leakage was back to the original number.

This shows the value of testing your work. We work with Quality Control Systems in our everyday work life. As consumers we depend on the quality of the products we buy. We see how companies respond when they are faced with a quality issue. A number years ago a lot of Tylenol was recalled. A few bottles had been tampered with, not really the manufacturer’s fault. They recalled anyway and their customers were well served. In the past few years, several auto manufacturers have had some problems with their cars, and they did not promptly recall the cars to fix the problem.

qcApplying good quality control lets the customers and the management of a company know the level of quality. The company can make drugs, cars, or install your heating and air system. In this case the quality work done by the Heating and Air techs was changed by another person working on the job. Good quality control found the problem. The fix took only a few minutes. Now the home buyer will not experience the discomfort from a badly installed duct system. I will not get a call in a few years because the home owner is not comfortable. The heating and air techs will not have a lot of call backs.

My thanks today goes to the crew at Cooks Heating and Air in Wichita. They did the quality work and deserve the credit. I am lucky to be able to work with people like this.

Those Pesky Directions

How many times have you started into a project and had to stop and redo some steps?  How many times have you finished and then realized that you had extra parts?  So what do we do?

Insulation RulerWe go back and read the directions! The manual!  It is so common there are several acronyms for reading the manual.  Directions written by the manufacturer serve several purposes. Some of the cynics around, including myself, realize there is a bit of self promotion and defense in these instructions.  We should also realize that the manufacturer has probably tried to put a few of these together. He may be sharing his wheel with us, so we don’t have to invent it ourselves.

Most importantly, the manufacturer knows how the piece was engineered. The directions take that knowledge and apply it to how the equipment is set up, used or installed. Equipment changes over time. New features are added, materials change and the way it used to be done, is not a good idea.  So, read the manual.

See the attic rafters above. This is the top of a vaulted ceiling, and the insulator has properly placed an insulation ruler.  In a few weeks, blown insulation will be installed and the tech needs to measure how much. The use of the ruler and blowing the insulation level are two of the biggest helps to installing blown attic insulation.  And Yes! They are in the manual!

The choice of this picture isn’t the insulation ruler, it is the nail grid on the ceiling joists. Machine applied in the truss shop, it is fast easy and effective.  Notice the upper right hand corner of the grid.  That is a sharp edge. Be careful, it will cut things.  Hands, pants, shoe tops. Yes! All of those and don’t ask me how I know that!  My wife makes me carry a first aid kit with lots of bandaids for a reason.Duct 1

The house I finished a rating on yesterday had these nail grids on the floor trusses between the basement and the main floor. It also had the HVAC Ducts run between and through the trusses.  The contractor on this job uses sheet metal supply plenums and take offs. He uses the flex duct to form the return air side of his duct system. Yes!  Flex duct gets torn also. Especially with a nail grid.

Two weeks ago, I tested this home. The duct system was very leaky.  According to the Quality Installation Verification Standard written by the Air Conditioning Contractors of America, it was leaking 100%. Wow!  I’ve tested this contractors work before. He always does better than this.  So I ran the test again. Checked my set up.  No change. So I called him.  Shon came right out.  He looked over the system and immediately saw a couple of problems. Including this section of flex duct.

ZeroNow, two weeks later, his crew has reworked their ducts. I’m back to test it again.  I run the same test and scratch my head.  What leakage –  I can get the readings right. The picture left shows no air flow, on the right side, and a very low pressure difference, on the left side of my manometer.  The procedure is to have the Blower Door depressurized the house. Then you depressurized the duct system with the duct blaster to equalize the pressure.  When the pressure difference comes down to Zero, you read the leakage to the outside of the house.

So I checked my set up and tested again. Still no readings.  So ….   I read the manual.  In this case a Field Guide from the Quality Folks at my RESNET Provider and The Energy Conservatory that makes my equipment. I read it twice.  Then it hit me.  This line: Check the duct pressure. A negative duct pressure indicates leakage to the outside. If the duct pressure measure Zero with the Blower Door running, then the leakage to outside is Zero CFM.

As you can guess, the leaks when I tested two week previous prevented this result. What changed?  The crew had found a small tear in the flex from one of the nail grids. Did you see it in the picture up above?  I can see it because I know it is there.  So I enhanced the image and that one is posted below.  To get around all the reflections of the silver colored coating, I placed a piece of white plastic inside the flex so the hole would show.Duct 2

So reading those pesky directions on a test that I routinely run, gets me the right answer. What about the Heating and Air Contractor.  Shon does good work on his jobs, because he follows the professional guidelines and tests his work.  In this case he knew the test, he knew what it meant and immediately saw how to fix it.  What would have been the result if this basement had been finished out and then he had to remove drywall to fix it?

Why is ZERO duct leakage to the outside important?  I don’t want to pay money to heat or cool the outside. If your ducts leak very much to the outside or don’t distribute the air properly, then you are spending more than you need to.  Installing ducts with no leakage to the outside in a new home is an easy process for the contractor. It give the home owner a much better value.

DuctLeak2 copyYes!  I have found duct leakage behind drywall also.  Here is an infrared image of a finished basement ceiling. The homeowners complaint is there is no air flow into his bedroom and it is cold in the winter and hot in the summer. To get this image I turned the furnace up to about 80° F. It was usually about 73° F.  I stretched out on the basement floor and waiting for the heat from the furnace to leak into the cavity between the main floor and the basement ceiling.  In a couple of minutes I had heat patterns showing.  You can see where the duct is running up and down next to the floor joist. Interesting heat spot to the right next to the other joist. Also across the joist and over to the left joist. So we are seeing the duct and hot spots on each side 16 inches away.  Lots of lost heat not getting into his bedroom.

The home with the infrared picture had the leaks on the supply side of the duct system. The one I tested yesterday had the leaks fixed on the return side. I could not have tested with the infrared in the same way yesterday.

So, on this Independence Day, we celebrate!  We celebrate our freedom to be in a business we love, where we can do some good, and make a difference.  And yes, where we can make a living for our families.  We also celebrate the freedom to know our job, to continue to learn as things change and to utilize our professional standards to keep our customers happy and satisfied.

Have a Safe and Happy 4th of July!

Credits:  Photos, myself.  Insulation Ruler –  Northstar Comfort Systems Install.  Duct system install tested yesterday with no leakage to the outside — Shon Peterman and Midwest Mechanical.  The audit providing the infrared image, my customer Craig. The new home tested yesterday courtesy of Sharon and Wade Wilkinson of GJ Gardner Homes. It is in Fontana.

 

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

What percentage of residential new construction cost do you think a high efficiency HVAC system should be? 5%, 10% ,15%???

This question was raised this morning on one of the professional discussion forums. Below is my response. Included is a link supplied by Richard McGrath in another response.

Let’s use a water bucket and a faucet for an analogy.

Take a page from the British Navy a few hundred years ago. They learned to tar the joints of their wooden hulled ships. Perhaps that’s why British Seamen are called ‘Tars’.

If you build your bucket with wood, you do something to stop the leaks. To use the bucket, you have a faucet to put water into it. If you put less money into the bucket stopping the water loss, you will need to put more water into it all the time, and need a larger capacity faucet. That will cost more money. The reverse is also true.

The question is ‘what should our faucet cost’? Most people would look at it and say not much! For a half million dollar house you might get answers from 2-4%. Some would say less. ??A faucet system is not just the part you see sticking out of the wall? The system includes pipe from the source of water to the house, to the various rooms where water is needed. You can’t buy a $10 faucet and claim to have a faucet system.

For this question, you can’t buy a furnace and AC unit and claim that is the system. You must have a Thermostat and some way to get the heat and cool to the various rooms of the home. For an effective faucet system, you put some thought and effort into the design. The same goes for an HVAC system.

What is the bucket in our house? Sometimes it is called the thermal envelope, sometimes Thermal Enclosure. It is formed by a continuous thermal boundary that is aligned with a continuous air barrier. ??Pretty simple in concept, Not as easy to execute. ??Put some time and effort into the design; then put some effort into the execution. If you are building with 2x4s use 24 inch centers, ladder connections for interior walls and 2 stud corners. Fill the extra room with insulation not wood. NAHB pioneered this in the 1970’s because of the high cost of framing material. ??You can install R-13 batts in those 2×4 walls, or you can use a blown in system. If you get the correct density and verify it, you can get R-15. You can choose a hybrid system with a 1 inch flash of CC SPF and blown in FG or Wet Sprayed Cellulose. R-17 or 18. ??Insulate the basement walls, crawl space walls and the above ground walls. ??Properly flash and seal the openings for windows and doors. Specify the U-factor and SHGC for the windows. Calculate the correct overhang for the eaves. You want to have them cast a shadow over the whole window at noon on June 21st.

Properly air seal the home. Install your WRB (water resistant barrier) correctly. That means following manufacturer’s directions. Wrap types mean gasketed nails, properly lapped and taped with approved products. You can use factory applied WRB to the OSB or a site applied liquid to the house. ??Air sealing doesn’t stop there. Fill each 1 inch hole the electrician drilled with caulk or foam, most wires running through those holes are about 1/2 inch. ??Then seal the joints of the wall and ceiling drywall on the attic side. Caulk or froth pac work. You can flash 1 inch of CC SPF also.

Now your house, bucket, is not very leaky. So you don’t need a big faucet. ??Big faucets relate to size of the HVAC system, they also directly relate to the cost to install. You also have the cost to operate.

After you have a well built air leakage controlled envelope, then you can consider the HVAC system. ??Two choices to start with: Hydronic or Forced Air. Forced air is most common in this area, we will persue that route.

After choosing Forced Air, you can choose gas fired heat or an electrically driven heat source. Again 2 choices. ??With a gas fired heat source you will have conditioned air leaving the ducts at 100 – 110° F. With an electrically driven source the air will leave the ducts at 85 – 95° F noticeably cooler. That will make or break many people on their choice and ultimate satisfaction with their HVAC system.

Gas fired comes in primarily Natural Gas and Propane. Availability is the key here. ??If you choose a gas fired system – go sealed combustion on the furnace and either sealed combustion or fan assisted drafting on the DHW.

If you choose to go with an electrically driven system, you can choose a Heat Pump or an electric furnace. If you choose an electric furnace, IMO you will not be pleased with your operating costs. They will be through the roof and you will invest any capital cost savings in operating costs very quickly.

That leaves a heat pump with Two Choices. You can choose an Air Source or a Ground Source. ??With a well designed and built duct system, meeting the standards for leakage and design for the Energy Star 3.0 program; a ASHP with variable speed ECM motor (which may be overkill) including actual Manual J, S, and D work ups around here will cost between 9 – 15 K. A gas fired system will be very similar in price, as would a dual fuel system.

If you opt for a typical closed loop Ground Source set up, including all of the above, wells and piping your capital cost will run between 25 – 35K. (noted for the next 27 months a 30% tax credit is available, but not considered in this article.)

In this area new construction homes range from 125,000 to 7 million. ??So the lower end is in the 7 – 12 % range. The more reasonable price of 500,000 for a high end spec home in the area results in the 3 – 7% range.

The question of percentages is silly. Builders may like them, but most homeowners will have their eyes glaze over if you bring this up. The goal is to sell homes, not HVAC systems. A home is supposed to be comfortable. Many new ones are not. This link goes into depth on this issue. http://www.healthyheating.com/Thermal_Comfort_Working_Copy/comfort.htm#.Uj9kLr7D_5o

The equation of importance is capital cost to operating cost. Those are best approached with some modeling. I recently completed a model for a 3K sf home with R-25 ICF V 2×4 16OC construction. The operating costs were in the $1,500 range for our utility rates. The HERS Score was 54.

Substituting a GSHP brought the operating costs down by $200 per year and increase the capital costs by 10K. ??The customer opted for the ASHP and ICF over the GSHP and typical construction. He chose where to put his money.

I see a trap in logic using percentages. I provided new construction pricing around here. My cousin in California deals with homes on the bottom range in the neighborhood of 500,000. That makes a hugh difference in the % equation. ??So try rephrasing the question to get some more accurate results. Leave out the percentages.

What Tools do you carry in your Tool kit?

I have all sorts of small items in mine; a list would include flashlight,  screwdriver, hammer, tape measures, wrenches, my blower door and infrared imaging camera.  Plus a bunch of flashlights. Yep!  A bunch of flashlights.  I like those everywhere, usually two at a time.flashlights

What kind of tools do you carry?

furnaceAn HVAC Tech might have the first part of my list, and a set of pressure gauges and thermometers instead of my specialized equipment.  Yes, I don’t really need his specialized equipment.

An Install Tech for an Insulation Company would probably have the general stuff and some specialized tools like an insulation blower, staple guns, and an air compressor.

Yes, the work you do requires certain tools. Most tools are fairly general and found in almost everyone’s tool kit, some are specialized to the work we do.

Now that I have pointed out the obvious, everyone maybe wondering why I’m thinking about tools and home performance. So lets connect the dots a little.

First, what happens if you get to the job and you can’t find a screw driver?  It has happened to me more than once!  I just hate that!  How many knife blades have we broken on our pocket knives when we find ourselves in that position?  We still have a job to do and the wrong tool takes longer, sometimes with banged knuckles.

What happens when the products or services we provide to our customers, can perhaps meet their need, like the blade on a pocket knife, but do not meet the need like a screwdriver?  That is the position many in the building performance are find themselves in.  They have a customer that is uncomfortable in their own home or a business with uncomfortable employees and customers.  How does the management design a solution for their techs to implement and thus satisfy their customer, making them comfortable again.  As a business, we each try to provide the solution to the customer from our stock.  That is how we get paid. You don’t pay the mechanic that fixes your car, when the plumbing needs to be fixed.  You pay the plumber, after the drain works again.

So you have a room that is Hot in the Summer and Cold in the winter?  Who do you call and what solution do the problem do you implement?Insulation Blown

If you call a Heating / Cooling contractor, they have equipment on the shelf, probably not insulation. So you will have a proposal to change your equipment for bigger units or perhaps to add a unit. The proposal will certainly involve equipment.  After all, if your mid size car gets you to the store, a larger car will get you there with more comfort.  Would you expect your HVAC contractor to recommend insulation?

What is the actual answer to to your comfort situation? Larger equipment with more punch or some insulation?  What if your solution does not involve either equipment or insulation?

Now we are back to the tools of our Trades!  What tools do you have?  Equipment, Insulation, Air Sealing, Windows?  The solutions you provide must involve the tools of your trade. That is why a savvy homeowner might consult with more than one contractor.  That is a great argument for savvy contractors to partner with contractors and others that work on changing the energy use in your home or business. Why should a good contractor limit themselves to providing only part of the solution.

Air SealingThis is happening in many areas of the country.  Contractors are partnering with others in their area to build home performance teams. There are contractors in Wichita that are moving in this direction.  I think that is great!

Deciding on the measures that will solve your comfort concerns, while bringing down your energy costs, involves a team that includes all of the contractors and a Energy Specialist that does not have a product on the shelf to sell you. The ability to recommend, without having a financial interest in the products, has been valued by many home owners. An Audit by Efficient Energy Savers, provides you with the independence in evaluation, and recommendations needed to get the answer you are actually looking for.

 

Some Results from Energy Improvements

When doing a Home Energy Audit, I always tell people that what I find is not good or bad. I tell them that what I can recommend for improvement depends on  the cost of their Utility Bills.

If you have a water leak, we all know that paying the price to a plumber to fix it, will cost us when the plumber comes. We also know if we don’t fix it, we can pay the water company that amount over 1 or 2 or 6 months. How long depends on the amount of the leak and the cost from the Utility for your water. And then we still have to pay the plumber. so we make a choice.

Blowing insulation into the walls!

Blowing insulation into the walls!

Wendy stuffing insulation into the hopper!

Wendy stuffing insulation into the hopper!

Some choices are easy, for improving the efficiency of a home.  Most homes with a tank type hot water heater inside the home, in a balanced or cooling climate (south of the Kansas / Oklahoma border) will benefit from installing a water heater insulating blanket.  They cost about $25.00 and typical savings just north of the above line can run from 6 – 8 dollars per year. So at $6 bucks a year, the blanket pays for itself in about 4 years. And most people can afford $25.00.

Other choices are somewhat tougher.  Instead of $25.00 to invest in the improvement, cost can run $2,000 to insulate a basement.  If you spend time down there, you know it is a little colder in both the winter (brrr) and the summer (nice), then upstairs.  Again, using some Wichita area numbers a homeowner could save in the area of $350 per year. Each house is different, so I am using some averages from various audits. If you apply this  savings over 6 years, the insulation is paid for and you still save the money. The hitch? It is harder to come up with $2,000 instead of $25.00.

In 2011, I had an Energy Efficiency Project approved under the Efficiency Kansas Program. They loaned some cost, I paid some costs and we added some (a bunch) of insulation, air sealing to cut the infiltration, replaced a 18 year old furnace and air conditioner. I also added an Energy Recovery Ventilator.

Wade in the attic! Fixing a dropped soffit in the kitchen! You can see the 3:12 pitch on my roof.

Wade in the attic! Fixing a dropped soffit in the kitchen! You can see the 3:12 pitch on my roof.

My payment over the 15 year loan is 870 per year, due monthly on my Utility Bill.  So the question is, how did I do with saving some money?  I have been tracking my Natural Gas and Electric billings, with numbers going back to 2009. When I changed HVAC systems, I went to an electric Heat Pump with a gas furnace for back up or emergency heat. As a result, my gas bill dropped and the electric bill, which includes the loan repayment amount is higher than I can remember.

To account for the change, I had to do something with the natural gas, billed in MCF (1,000 cubic feet) and the electricity, billed in KWH (kilowatt-hours).  I decided to convert the gas usage to KWH for ease in comparing before and after.  I also wanted to be able to compare usage against the weather.  Some summers are hotter than others and some winters are warmer then others.

The National Weather Service tracks our weather very well.  You can get an F-6 Report from most airports around the country. In Wichita, we have a choice of 3.  There is Mid-Continent, the primary commercial airport; there is Jabara Airport, a smaller facility that specializes in private airplanes.  And we have McConnell AFB.  All have weather observations and reporting.

The F6 NOAA Report for March, 2011 at ICT. The 2 columns between the red lines show the HDD and CDD.

The F6 NOAA Report for March, 2011 at ICT. The 2 columns between the red lines show the HDD and CDD.

How did I compare the before and after?   Excel works great for prototyping number crunching and charting the results.  I collected my data on usage, cost and Degree Days from the Weather Service.  I built two charts. First one covering January 2009 through present. After looking at this chart, I built another showing January 2011 through present.

The charts show three (3) lines. The Blue Line represents Heating Intensity by month.  I took Heating Degree days, multiplying by 5.  The Red Line represents Cooling Intensity by month. I took Cooling Degree days, multiplying by 3.5.  The Green line represents Energy, show in KWH.  I converted my gas usage to KWH by ” MCF x 293 “. Then I added the KWH from Electric and Gas to chart the Green Line.4 years

2009              2010                     2011                  2012                 2013

If you look at the top peaks of the Blue Line – you see the cold months. Imagine a level line averaging those tops. Somewhere between 4000 and 5000 on the Y-Axis. Look at the Red Line Peaks – you see the hot months. Imagine a level line on the Average of those peaks, just a little over the 2000 on the Y-Axis.

Now look at the Green Line, it goes up in the winter, and summer, down in the spring and the fall. This line doesn’t really run level on the peaks. If you pick about 6500 on the Y Axis in 2009 and 2500 in 2013, the line slopes down.  The Red vertical line shows when the improvements were made. This chart shows 3 years prior to the date of improvements and 1 year after.

The Chart below just shows one year before and 1 year after.  So the horizontal spreads out a little. I think the point is made in either chart.  The improvements require less energy to be purchased.

How much less in dollars, instead of Energy Usage? I’m saving my 870 annual repayment amount plus enough to repay myself over 15 years for what I kicked in.  And a little extra.

2 years

2011                                    2012                                   2013

Some one will ask why did I adjust the HDD and CDD numbers.  I did it to match the scales on the charts.  I first set it up with direct numbers. When you looked at the chart you could not make out any significant ups or downs to compare. So I reworked the numbers with multipliers, to make the charted numbers line up better.

In September, 2011 the chart shows 155 HDD, 591 CDD, the energy usage in KWH is 2261.  In September, 2012 the chart shows 0 HDD, 960 CDD with 1217 KWH used. Using the same Y-axis scale required some changes. So I used a multiplier to move from direct Degree Days for Heating and Cooling to an intensity measure for heating and cooling.

Thanks for following along.  I will make another post with more of this story.

Build Your Own Home Energy Audit

A comprehensive Home Energy Audit takes time and covers a number of areas. It provides lots of information and recommendations.  A homeowner may choose to limit the inspection to those items of their concern.

The energy efficiency of each home combines an analysis of the components of the home and how well they are installed.  Think of a bucket of water, the bucket is the walls and ceiling of your home. A pinhole in the bucket will drain the water from the bucket and the heat from your home!

A Home Energy Audit looks at the ability of each building component to resist the transfer of heat. The air tightness of each component is also reviewed.

This post covers a description of each part of a comprehensive Home Energy Audit.

Pricing, previously contained in this post, is posted separately.

Utility Analysis

The actual usage over the last 12 months of Electric and Gas is compared to the home size and evaluated. This requires information from the Utility Companies.

Infiltration Testing                 

(Multi-point Blower Door Testing with Thermal Imaging and Indoor Air Quality Analysis)

Everyone has felt a cold draft at one time or another. Since the air blew in and the house didn’t pop like an overfilled balloon, the air blew out somewhere else.  This test simulates a 20 MPH wind on all four sides of the home at the same time. It allows an actual measurement of leakage and it identifies the leaks. This allows a specific plan for the leaks in your home to be fixed.

The recommendations will include effective measures to improve indoor air quality, not just install what the salesman has in-stock. If you have de-humidifiers running this Testing is important.

Ceiling Evaluation:

The ceiling and attic areas are examined for insulation, ventilation and thermal bypasses. This is done from the outside of the home, the inside in all rooms and from the attic. It may involve remote camera usage. If Infiltration Testing is part of the package, information from the Thermal Imaging portions are applied to the ceiling Evaluation.

Foundation Wall Evaluation (below grade):        

In most homes a major source of heat loss is from the crawl space, the slab or the basement walls. There are generically referred to as the foundation of your home. Traditionally, builders have confused the thermodynamic principles involved, with hot air rising and heat loss, to falsely assume that basements cannot be kept warm.

Wall Evaluation (above grade):

Homes over twenty years old, or homes with a major insulation failure may benefit from a specific wall evaluation for walls above grade.  It is part of a comprehensive  energy audit. All wall evaluations are conducted with Non-Destructive-Test Methods to start. Depending on the home, the type of construction, access to various areas, further testing that involves minor holes being drilled will be discussed with and approved by the homeowner before the end of the evaluation.

The condition and energy efficiency of your exterior siding is done at this point.            

Equipment (furn. AC, hot water):                    (Includes safety checks on Gas Fired Equipment)

Your heating and cooling equipment is a large investment. What are the efficiency ratings on your existing equipment and what is available on the market? How does a home owner sort out fact from sales pitch.  This inspection includes safety testing for gas fired equipment. Furnace, Heat Pump, AC, Hybrid Heat Pump, are included.

Windows and Door Evaluation:           

Windows are advertised everywhere.  On the Radio, TV, the newspapers and other print media all carry large volumes of sales pitch for replacement windows. The FTC has fined some window companies for outlandish claims on energy savings.

Are your windows an energy problem? Can those energy problems be fixed or should the windows be replaced? What is the best for my home?  Low E, argon filled, double pane, triple pane? How does a double pane window save energy?  All these questions and more are answered. And you get the answers from someone that does not have a financial interest in your purchase or non-purchase of a product.

Windows and Doors are both holes in the wall.  From an energy loss standpoint there is not much difference. Doors are not as heavily advertised, but they are pushed after the salesman gets to quote your home.          

Computer Modeling and Reporting

The Comprehensive Home Energy Audit provides a complete energy usage model and reporting of problems, recommendations and solutions. Interactions between building components are considered in the computer model. You can go from the report to soliciting firm prices from a contractor or doing it yourself with this report. This reporting will qualify for applying for and Energy Improvement Mortgage if you are buying a home, or refinancing your current home.

If you choose various parts of the Home Energy Audit, written reports and recommendations will also be provided. These will all you can go from the report to soliciting firm prices from a contractor or doing it yourself with this report. The reports are limited to the selections made. Interactions between building components are not considered.

Duct Leakage Testing Not included in the comprehensive audit.

Some comfort and energy loss issues involve improperly installed ductwork. Testing is easy. Fixing these problems can vary in complexity depending on the home.      

Lighting and Appliances Not included in the comprehensive audit.

Incandescent, halogen, CFLs, LEDs, which is best for your home?  Not every fixture needs a high efficiency light! Should I get a new fridge or other appliance?  All these are part of the Lights and Appliances.

Bonus Room (over the garage, or in the attic) Included in the comprehensive audit.

Rooms placed over a garage or in the attic are a special case. They are part of a comprehensive audit. They can be an individual item, with infiltration testing, due to the unique construction problems with them.

For more information or to schedule a Home Energy Audit:  

V / T  316 641-5258  or  email:  info@efficientenergysavers.com