Category Archives: Industry Best Practices

Quality Installation and Maintenance of HVAC Equipment

The news this month has multiple stories about Heating and Air Companies being very busy with units not cooling or not cooling enough.Screen Shot 2016-06-24 at 8.49.56 AM Driving around town, I see most of these contractors have a sign out front looking for help. The wait time is up to two weeks.  In the 7 homes I’ve been in this week.  One had no working AC, one home was on it’s last legs, and two other homeowners were very concerned. For the 1st time in 7 years, I’m getting calls from my website asking if I can fix their AC unit.

This morning I found a report on HVAC Problems, Problem Identification and Repair.  I have scanned this 27 page report and these are the things that jumped out.

Background:  California has some of the toughest energy requirements for buildings, both new and remodeling of existing buildings. These is a direct result of the problems they had 15 years ago, with not enough electricity.  They resulted to black outs, (Utilitys were allowed to shut off electricity to various geographic areas).  and brown outs, (Utilities were allowed to provide only part of the electricity needed to a geographic area).  Both are not good.

These energy codes are generally referred to as Title 24.  A large part of the work in California the last few years has been testing and measuring how well the requirements are being met.  This report is just one small piece of that process.

Title 24 refers to the problems, their identification and repair as “Fault Detection and Diagnosis” or “FDD”

Screen Shot 2016-06-24 at 8.51.18 AM

The Report was working on the answers to these questions

  • Is FDD worth the investment, and what is the savings potential?
  • How effective are available FDD methods and what do they cost to implement?
  • What training is needed for effective FDD and is it being provided?
  • Are codes and standards working?
  • What are the major gaps and how can they be addressed?

This particular session and reporting was limited to:

 

  • System Types–new and existing residential only
    • Air conditioners
    • Heat pumps
    • Furnaces and air handlers
  • Fault Types
    • Low airflow
    • Refrigerant system charge, restrictions, and contaminants
    • Mechanical and electrical faults and faulty installation
  • Repair vs. Replacement Issues
    • Cost-effectiveness of FDD
    • Replacement refrigerants for R-22
  • Human Factors
    • Training and quality of maintenance
    • Homeowner knowledge and expectations.

The reporting included tests applied with standard AHRI methods. The tests were designed to determine the impacts on efficiency and capacity of a variety of conditions, including:

  • Airflow of 250 cfm/ton reduced energy efficiency ratio (EER) by 12% and has the potential to produce a false overcharge diagnostic due to freezing of the coil (the asterisk denotes an unofficial EER)
  • Liquid line restrictions (e.g. due to clogged filter-dryer or metering devices) reduced EER by 30% to 36% for non-TXV and TXV systems respectively
  • Only 0.3% Nitrogen in the refrigerant reduced the EER  by 18% with no TXV and 12% for the TXV-equipped system

Discussion pointed out that California Title 24 charge verification methods, which only measure superheat (for non-TXV) and sub-cooling (for TXV) systems, and ACCA Standard 4, for which only 3% of the procedures are related to energy performance. Also covered were  how improperly maintained vacuum pumps, test instrument error, and poor service practices such as use of rules of thumb contribute to the introduction of non-condensables, improper charge, and other faults.

John Proctor, PE presented a case for making improvements to California’s Title 24 standards, John worked with a team to inspect a large number of recently built homes to identify HVAC installation and performance issues. He began his presentation by defining an “incremental effectiveness ratio” that divides benefits of maintenance by the incremental cost to diagnose, repair, and ensure quality, which is fundamental to the question of the value of HVAC service. He proceeded to show a series of graphs from his experience and other studies that illustrate the deviations from the ideal for airflow, charge, duct leakage and efficiency, and non-condensables, as well as the incidence of occurrence of these defects.

For example, his graphs show:

  • 50% reduction in airflow reduces EER by 25%.
  • A refrigerant charge that is 70% of the recommended charge reduces EER by about 55%.
  • Leaving Nitrogen in the line set and coil at 20 psig before charging with refrigerant reduces the sensible EER by about 45%.
  • From his 2003 survey, more than 60% of the houses checked failed on refrigerant charge, airflow, and duct leakage, and more than 95% failed overall.

Many of these issues result from a lack of training and a lack of follow up by supervisors.

They had some specific things that could be done by builders, HVAC Contractors and home owners to ensure these items do not get missed.

I will read the report in more detail and have further comments.

You may read the entire report.

What is an Energy Audit Worth?

Hose and bucketSeveral years ago, I wrote a post about the value of an Energy Audit.

The story behind that audit was one side.  Improved Comfort. This time it is about the other side.  Decreased Cost of Operation.

An home energy audit reviews the ability of your home to retain the heated air from your HVAC System in the winter and the cooled air in the summer. The best metaphor I’ve seen is to compare the Thermal Enclosure to a Bucket of Water. The picture above is a good example.  The hose is like the HVAC System. It fills the house with hot air in the winter and cool air in the summer.  The Bucket allows the conditioned  to leave the home.

The result of the energy audit is to prioritize which holes to fix first, second and third. Some of this is about how big a thermal leak the hole is, and some of this is about cost.

Attics are less costly to insulate than walls.  There is room for more insulation, it is not a lengthy process, and there is nothing like patching holes after you have insulated.

This home had the improvements made as recommended by the audit, in February 2012.  The energy usage for 36 months prior to and now 36 months after the improvements is now available.

The 3 year average for annual energy use before the improvements is 34,972 KWH.

The 3 year average for annual energy use after the improvements is 18,940 KWH.

A decrease of 45% in energy used.  The bills are paid in dollars, so why refer to an energy measure.  Using energy measures means future increases in Utility Rates are not considered.  Will those increases happen?  Yes! Not counting on them is important. Did they happen during this 6 year period.  Yes, several times. So the results are about actual savings.

IMG_1272 copy

Here is Brian, blowing insulation into the walls. The walls before the work started were uninsulated. If this home had been stucco or brick, this step would not have been cost effective.  The material is cellulose, providing an R-13 in the wall. Cellulose is easy to install in this application. This crew had done this many times and the experience is worth a lot.

IMG_1340 copyThe image on the right is the attic. As you can see there is a little insulation in there before work started.  That meant the crew could do the air sealing first.  Fibrous insulation like the rock wool you see, or the cellulose that was added, does not stop air movement.  Warm air from inside easily goes up into the attic and outside. Good crews air seal before they insulate. They are already up there.  A caulking gun is not hard to carry along.  See those wires,  the electrician drilled a one inch hole to put the wire through.  Lots of air leakage.

Here is a picture I took last winter.  New snow the night before  on the roof of this house. Note the hole near the edge of the roof in the snow cover.  That hole in the snow is right over the outside wall and there is a light switch, or outlet on the wall below it.  Air Leak copy

 

Indoor Air Quality – Guideline Revision Public Comments Requested

imagesATLANTA – Public input is being sought into a proposed revision of ASHRAE’s residential indoor air quality guideline.

ASHRAE Guideline 24-2008, Ventilation and Indoor Air Quality in Low-Rise Residential Buildings, is the companion guideline to ANSI/ASHRAE Standard 62.2-2007, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings.  Guideline 24 provides information on achieving good IAQ that goes beyond the requirements contained in Standard 62.2 by providing explanatory and educational material not included in the code-intended standard.

Read Entire Article

 

Be Proactive for a Green Appraisal

greenlightbulbWhen it comes to getting an accurate appraisal for a high-performance home, it’s easier and more practical to take the right steps up front than to try to get a low appraisal revised after the fact.

Appraisal expert Sandra Adromatis, a featured speaker at the High Performance Building Zone during the recent International Builders’ Show, offered advice for securing an accurate appraisal of a high-performance home.

First and most important is documentation, especially of features behind the walls and other items that aren’t immediately obvious.

A good place to start is by taking a close look at the Appraisal Institute’s Residential Green and Energy Efficient Addendum. This is particularly important if the home is built to a nationally recognized program like the ICC-700 National Green Building Standard or includes additional high-performance features that should be documented within the appraisal.

This article appeared on the NAHB Blog.

For the complete article

Ms. Adomatis also presented at the RESNET Conference after the IBS Show. I furnish the Energy portion of the AI Energy Efficient and Green Addendum for every new home rating I do for a builder.  If you would like to see one or see how it would help your building plans, give me a call.

Passive House Verifier Training Part 1

PHIUSPHIUS (Passive House Institute United States) is one of two organizations in the US that promote and issue certificates for completion of a home that uses extremely small amounts of energy to heat and cool a home. The other organization is an affiliate of the German PassivHaus Institute.

This organization is based in Illinois. The goal is to make passive building principles the mainstream best building practice, and the mainstream market energy performance standard.

prosocoWhat is a Passive House? It is a home that people want to live in. It must be comfortable for the occupants and it must use very small amounts of energy to heat and cool; and for total energy use as well. RIGHT: A Passive House under construction.

Design for a Passive Home emphasizes energy efficient features that are installed during the construction of the home which do not have moving parts. The design relies on all parts to be installed to manufacturers specifications. These details are verified after they are installed.

Smith HouseThe idea is that insulation and air sealing are very cost effective compared to large and sometimes complex new technology in HVAC Systems. Instead of buying the expensive technology, use the money, that would usually spent on upgraded HVAC system, to increase the insulation levels. The details of how much insulation, what type and where are certainly of interested to  the builder and others involved in planning and construction. These details are less important to the home buyer, they just want things to work at a lower cost.

I am writing about Passive House construction since I just finished the training and testing to become a Passive House Verifier with PHIUS. You will hear more about the Passive House concept and how it might apply to any home.

The First Clothes Dryers to Earn the Energy Star Label Now Available Nationwide

ES DryerEnergy Star Press Release Date: 02/10/2015

Contact Information: Jennifer Colaizzi, colaizzi.jennifer@epa.gov, 202-564-7776, 202-564-4355

WASHINGTON –The U.S. Environmental Protection Agency (EPA) announced today that Energy Star certified clothes dryers are now available nationwide through major retailers. At least 45 models of dryers earning the Energy Star label, including Whirlpool, Maytag, Kenmore, LG, and Safemate, are at least 20 percent more efficient and now available at prices comparable to standard dryers. 

“Dryers are one of the most common household appliances and the biggest energy users,” said U.S. EPA Administrator Gina McCarthy. “EPA’s Energy Star certified clothes dryers offer Americans an opportunity to save energy and do their part to combat climate change. By working with industry, we are bringing innovative technology to market that’s good for the planet.”

Clothes dryers consume more energy than any other appliance in the home, and 80 percent of American homes have dryers. But unlike clothes washers, which have seen a 70 percent drop in energy use since 1990, the energy efficiency of most dryers has not improved. If all residential clothes dryers sold in the U.S. were Energy Star certified, Americans could save $1.5 billion each year in utility costs and prevent greenhouse gas emissions equal to the electricity use from more than 1.3 million homes.

The efficiency specifications were developed with extensive input from manufacturers, retailers, the U.S. Department of Energy, and environmental groups. Manufacturers meet the specification requirements by incorporating advanced sensors that more effectively detect when clothes are dry and stop the dryer.

Energy Star certified dryers include gas, electric and compact models. The Energy Star label can also be found on dryers that feature new advanced heat pump technology and are 40 percent more efficient than conventional models. Heat pump dryers recapture the hot air used by the dryer and pump it back into the drum. By re-using most of the heat, a heat pump dryer is more efficient and avoids the need for ducts.
For the complete Press Release:

Poll: Energy Efficiency is America’s No. 1 Housing Concern

Safety, affordability and privacy – it’s no surprise that these were some of top housing needs identified in a recent national survey of more than 10,000 households. But the No. 1 unmet housing concern, which the Demand Institute that carried out the poll defined as the “satisfaction gap” between what respondents actually have and what they said was important, was not as easily expected: energy efficiency.Insulation

Survey respondents were given a list of 52 housing and community concerns and asked to rank them, on a scale of 1 to 10, by how important they felt the issues were and how much their current home satisfied these needs. The result: 71 percent of U.S. households polled placed a great deal of importance on energy efficiency, but only 35 percent felt their homes were very energy efficient with low monthly utility costs (the respondents making up percentages answered these questions with an 8, 9 or 10 ranking).

To read more continue here

What Counts? Product A or Product B

Blower Door Testing & Weather Resistant Barrier

Tyvek TopThe practice of covering sheathing with asphalt impregnated papers has given way to the use of synthetic fabrics, known as house wrap; or spray on coatings. There are factory applied coatings on some brands of sheathing and some types of coatings are field applied. Along with the discussions of fiberglass / cellulose in the insulating of homes, there has been plenty of discussion about the merits of one form or another of WRBs.

As with any step in the building process, I believe it is less about the product and more about the people. Products that are hard to install will be less successful then others. Installers that are not properly trained; work that is not verified in some manner can defeat the proper performance of the best products.

WRBWhat does the WRB do for a home. First it provides a drainage plane behind the siding to divert rain and other weather related moisture from wetting the sheathing. Second, when all manufacturers install instructions are followed it can act as an air barrier, reducing infiltration. For the house wrap type fabrics, this means properly lapped, using capped fasteners, and then taped. Finding house wrap installed according to manufacturer’s install directions is rare.

When all three of these directions are not followed, not only are the potential qualities of an air barrier not present, the potential for water to run behind an uncapped fastener, or an incorrectly lapped joint, which is also untaped. Repeated wetting of the sheathing over time, will eventually result in rot and the accompanying problems.

Country HollowA local Wichita Home Builder, G.J. Gardner has just finished two homes based on the same floor plan. These homes went through the independent verification process involved in obtaining a HERS Rating. These homes utilized the same sub-contractors and types of insulation. The only difference in construction was the use of a job site applied spray on WRB, in place of a house wrap type fabric.

One part of this verification process is a Blower Door Test. This test simulates the effects of a 20 mph wind on all sides of the home at the same time. Blower Door testing has been completed on homes since the late 1970’s. Energy efficiency programs and building codes have consistently recognized the value of a Blower Door test on each home.

BlowerDoorThe value of doing a Blower Door test on each home is primarily to check the work of all subs has not compromised the Builder’s plan for an energy efficient home. Many existing homes, have a test rate of 7 – 12 or higher rates of air exchange during the test. The 2012 code requirement is 3 on this scale, and lower is better.

The use of 4×8 sheet goods for sheathing and other simple, and inexpensive techniques have brought the infiltration rates down. This reduces the cases of cold drafty homes, and significantly lowering the energy use of a home.

The Blower Door test can verify the quality of work involved with installing the WRB, specifically the degree of sealing of the outside of the sheathing. In the case of the two homes involved in this comparison, there was a change of 20% in the measured infiltration rates of the two homes.

In completing the Blower Door tests, we used the ANSI / RESNET published standard of a Multi-point test. These results were entered into a software package provided by the maker of the blower door, The Energy Conservatory, Below is a comparison screen between the two Blower Door Tests.

Tectite 2 Bldg Comp Data

I would like to thank Wade Wilkinson, with GJ Gardner of Wichita; his subcontractors and their technicians for building quality energy efficient homes. I enjoy being able to verify the quality of their work.

If you would like to see this home, it is currently in the Fall 2014, WABA Parade of Homes.  It is located in the Country Hollow Development.  Between Kellogg and Harry on 127th and East to Glen Hills Court, on the corner.  Find out also about the HERS Index earned by this home. It will save you operating costs on your Energy Bills.

Passive House Work in Wichita

In the last two weeks, two national groups that certify construction for Passive House Standards conducted their annual conferences.  PHIUS was held in Portland, OR; and PHI was held in Maine. Locally, I have completed the first of 3 planned Blower Door tests for a passive concept home under construction; discussed the planned construction with another builder to start later this year; and discussed passive building concepts with another builder planning his first homes next year.

PassivhausDarmstadtKranichstein-300The Passive House concept started in Germany, with construction starting in 1990 on several homes. In German, it is Passiv Haus,  PHI for Passiv Haus Institute.  The standards followed by this concept require an attention to detail in design and construction of the thermal enclosure.  Historically referred to as the envelope, the thermal enclosure involves the exterior bottom, sides and top of the structure.

  • Higher than commonly used levels of insulating material,
  • windows meeting specific standards and very
  • Effective work on air sealing
  • Attention to the Solar Orientation of the home to maximize the use of solar heat in the winter

PHIThis results in an extremely low energy bill.  How low? In the Wichita area, this would translate to an $88 – $110 annual natural gas bill, instead of $500 – $900 bills that I routinely see on Home Energy Audits.

The passive term comes from the idea of using insulation and construction techniques to create a significant energy savings instead of relying on fancy machinery to create that savings. Dr. Wolfgang Feist of Dahrmstat, Germany founded the Passiv Haus Institut in 1996.

Smith HouseThe passive house concept arrived in the US in 2003.  Katrin Klingenberg, a licensed architect in Germany, She built a home meeting these standards, 2 hours south of Chicago.

 

Most countries have a local organization that trains and certifies homes and commercial buildings to the Passive Standard. Yes, passive concepts apply to buildings other than homes. These groups train people to apply and measure the standards. They also review the reports on specific buildings and accept or deny actual certification for a specific building.

PHIUSIn the US, this organization has been known as PHIUS.  Passive House Institute, US. Ms Klingenberg has been the leading light of this group, which was founded in 2007.  There are some things in each country that differ from the original German model of Passiv Haus.

The experience of the professionals working with PHIUS in the US has resulted in some changes to how the concept is applied in the US. For example, the metric units used in the German (and most others in the world) have been translated to the Imperial units used in the US. The collaborative nature of US business groups has been essential to moving the passive concept from being used by a relative few to becoming a market force in the US.

Because these adaptations by PHIUS to the US market, were not acceptable to the original PHI, a divide between the approaches has occurred in the US.  It is mostly technical, and both groups agree the concept is still primary.  Effective building resulting in low energy use.

Some claims have been made that these concepts are two expensive for the US market. The original Passive House in Illinois was built at a 2003 cost of $94/ sf.  That is very favorable with current US construction costs. Since additional people are using the concept and the resulting products that manufacturers are producing, the mass production will bring some drop in costs.

If you wish to read more about the two national conferences for both the PHI and the PHIUS organizations that just finished, you may use these articles.

The 9th annual North American Passive House Conference (PHIUS)

Report from the Passive House Conference in Maine

I will keep you updated on activity in this area about Passive House building activity, as it progresses.  Three projects is a great start.  I’m glad that builders are willing to try new concepts and that home buyers are willing to step up and buy these homes.

In the introduction of this post, I mentioned a house under construction with the Passive House concept. I conducted the first of 3 Blower Door Tests last week.  This test was after the framing and exterior sheathing was completed.  Insulation, plumbing, electrical and trades had not started.  The second test will be in a few weeks after these trades have done their initial work and put holes in the enclosure.  Electric wires, plumbing, HVAC and other necessary conveniences of our lives will be installed in passive concept homes. The third test will be done at the end of construction.

The PHI/PHIUS standard for Air Infiltration as measured by the Blower Door Test is 0.60 –  The current 2012 recommended code requirement for this is 3.0 — Wichita/Sedgwick County does not have an energy code in place, but the Kansas City area does. They enforce a 5.0 standard.  Typical homes built from 1980 and prior are in a range of 10 – 38 from my testing.

The goal of the builder on this passive concept home was to reach 1.5 on this first test. Then using the Infrared Camera to find areas to caulk, and fixing the penetrations mentioned above, have the next test come in lower.

Blower Door62This test, actually came in at 0.62 —  almost the standard.  Much better than the expected 1.5 .   While the blower door was running, the Infrared found some places that could be fixed.  Dan, the carpenter, was right there with a caulking gun.  We also found some leakage with biometrics. A back of your hand that is wet, will show you extremely small amounts of air movement.  Most builders like to use expanding foam to seal the actual window to the rough opening.  We found some of these foamed openings were still leaking. Again the caulking gun was a good answer.

 

A Healthy Home Part 3 — Well Ventilated

Fresh AirA Healthy Home is well ventilated.  Everyone knows fresh air is important. This should be easy.  Well ventilated in more than just bringing in fresh air. The concepts are certainly easy, the details on the other hand take some thought and planning.  A new home ventilation strategy is fairly straight forward to design and implement. An existing home needs the input from the occupants and good analysis to address the problems. An effective ventilation strategy should address these issues in either new or existing homes.

  • Remove humidity, odors,, or significant problems from specific areas.
  • Remove stale, musty or other objectionable air.
  • Allow the occupants to choose fresh air sources that can be filtered or treated in other ways
  • Allow the occupants to choose to open windows when outside weather is appropriate
  • Allow the occupants to operate a system that can provide the amount of fresh air, to the appropriate places, in adequate amounts when needed
  • Provide fresh air when the outside air creates potential problems, such as Ragweed season or when other allergens are active
  • Provide air movement within the home, without the use of the expensive blower on the furnace or heat pump.
  • Allow minimal use of heating or cooling equipment during the shoulder seasons, when temperature changes are minimal, while keeping the home comfortable.

Billings QuoteHow much fresh air is needed?  Going back to the 1890’s, the number has been pegged at 30 CFM (cubic feet per minute) per person. This number was validated in a number of different studies and with the public health authorities in larger cities, dealing with large apartment buildings and recurring respiratory diseases.  I was pointed to the quote at the left by Allison Bailles. he located the original book on Google Books, page 20.

Beginning in the 1930s, research into changes in building techniques began to show the optimal number was closer to 15 CFM per person.  Some of the changes in construction included the increased use of forced air heating, moving from balloon framing to platform framing, increasing square footage, and the use of insulation in walls and attics. The formula changes from time to time and everyone has an opinion on details. The common point remains, fresh air is needed in every house.

Part of the Ventilation is removing air with a problem. Where is that?  Humidity is found in rooms that use hot water and basements.  Showers, tubs and cooking are the large sources of humidity.  The smells from food preparation and cooking can be very mouthwatering.  When the meal is finished and the refrigerator is full, the lingering smells become odors.  The answer is some spot ventilation in these areas. If your basement has a humidity problem, you can tackle that with a fitted sump pump cover to contain the humidity, and work to eliminate any water seepage.

vent fanSpot ventilation is a window that opens and an exhaust fan. The size of these fans is part of the formula that is specific to each home. The features of the fan are common to all homes.  It must be quiet. Builder grade fans are noisy. Noise in fans is measured in ‘Sones’. The Sone is a linear measurement of noise, compared to the decibels used by OSHA and others which is an exponential measurement.  Linear is better for quiet sounds, and decibels is better for loud noises. Fans should be less than 3 sones, and preferably less than 1 sone.  Reasonably priced fans are available that rate a 0.3 sones. A 1 sone fan is very quiet.

UnknownFans are certified for air flow and noise levels by the Home Ventilation Institute. HVI certification is very common and includes both the Sone rating and CFM rating.  When installing a fan, you must consider the duct losses that will occur in meeting the required air flow.   The rates for bathroom air flow  are 50 CFM, and 100 CFM for a kitchen.  Do not expect to buy a 50 CFM fan for a bathroom and connect it to 6 or 8 feet of duct work, and obtain 50 CFM.  I have measured 30 CFM routinely in these set ups.

Most people understand that various parts of their body are just a part of the whole.  If you start some type of therapy, there may be a side effect. Physical Therapy starts and you end up with some sore muscles, aha!  Side Effect!  Start a therapy for cancer and your hair may fall out, aha! Side Effect!  Your home works the same way.  Each part is just part of the whole. Change something, aha! What is the side effect?

House-System-imgAll of the items in the list above are part of the whole. For an existing home, some specifics of that house may indicate concentration on one or another of those areas.  A home built in the 1920’s will benefit from a different approach then a house built in the 1980’s.

A new home should have the ventilation system that meets the general points above.  The natural ventilation provided when windows and doors are opened, or the mechanical ventilation system that allows filtered and perhaps treated fresh air brought in from specific places and in specific amounts, allow the occupants to make the system work as they need.

 

This post is part of a Series on A Healthy Home