Icing the Cake

When dressing my seven year old son to play in the snow, I always remind him to where his hat. It's what my Mom always told me.  And the truth is that it's the most effective way to stay warm.  By keeping one's head warm, you're insulating your largest source of heat loss.

2x8 rafters leave little space
to add insulation

Now what does this have to do with home energy efficiency? Well, it's the top of the home that is one of the largest heat loss sources. Wouldn't it be great if we could fit attics with knitted caps?

Probably the single most discussed issue when it comes to improving energy efficiency in rehabbed homes is how to effectively insulate their attics.  This is especially true when occupied attics have complicated configurations.

I don't have all the answers, but here are some quick lessons learned:

To ventilate or not to ventilate... that is the question

There doesn't seem to be a wrong answer to this question as long as your decision is accompanied by the appropriate details.

If You Decide to Ventilate the Roof

Sometimes abandoning a formerly
occupied attic and filling with
insulation is the most cost
effective solution

1. Entirely abandon occupied attic spaces.  This allows you to fill the entire attic floor with insulation to as great a depth as possible.  By placing the attic outside the thermal envelop, you can avoid the whole issue of how to insulate the cathedral ceiling.  The attic now has plenty of space to breath.  Remember to use baffles so that ventilation flows from eave (low point) to ridge (high point) as code requires.

2. Insulate between the rafters. Attach rigid insulation to the rafters and fill the cavity with cellulose or fiberglass.  But remember to again use baffles in order to maintain a small 1" ventilation space between the insulation and the underside of the deck.  The space should be continuous from the ridge to eave. If moisture should enter the space, it now has a way of drying out without doing damage.

If You Decide to Install an Unventilated Roof 

3. Provide an air barrier on the underside of the roof deck and then insulate.  This is achieved by securing rigid foam insulation between rafters and filling gaps with foam (Notice we are not using spray foam only because historic preservation rules prohibit its use within walls and/or ceilings).  Now the space between the rafters and under the rigid insulation can be filled with dense packed cellulose or fiberglass.   The layer of rigid insulation creates an air barrier which prevents the dew point from moving into the dense packed insulation.    The challenge lies in squeezing as much insulation as possible between rafters that are only 8" deep or less.

4. Provide the air barrier on the top side of the roof deck.  This allows you to reduce if not eliminate the amount of  insulation being stuffed under the deck, but it has consequences for the outside of the building.  Fascia and eave profiles will be modified and the roofing contractor is now responsible for installing a layer of rigid insulation and sheathing.

Rehabilitating old houses is an art.  And seeing icicles forming on the eaves of recently insulated attics (see attached pictures) is disheartening.  The icicles are an indication of heat loss.  The good news is that with experience comes improved techniques and more effective solutions.




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For more detail and discussion checkout:
"Insulating Cathedral Ceilings", Fine Homebuilding Magazine, June/July 2012 (#228), pg. 66.

House Entrance Exam

Here's a new term home buyers should learn.  It's called a HERS rating and I just spent the morning witnessing all the exams required to provide an East English Village home with one.  HERS stands for Home Energy Rating System.  A score of 100 means that the home's energy performance is equal to that of a home built to minimum energy code standards.  A score of 85, which is required for any home meeting Energy-Star standards, means the home will perform 15% better.  In other words, the lower the score, the better energy performance.

Minneapolis Blower Door
Source

The data collected in the series of tests performed today will be input into modeling software, which will generate the home's HERS rating.  The following tests were performed today:

The Blower Door Test

To perform this test, the home is de-pressurized by sealing all openings except one, typically the front door.  A fan is placed within this opening.  When the fan is turned on, it pulls air out of the house.  The fan pressure is raised to 50 Pascals (Pa) and using the gauges attached to the fan, the amount of air being pulled into the house through cracks and openings is measured.  The rate of leakage is measured as the number of air changes in an hour, or ACH.  Current energy code requires all new homes to have a maximum of seven (7) ACH.  For a typical home, like mine which was built in the 1960s, this number is typically around 14 ACH.  Today's renovated home performs well with 8 ACH.

Duct Leakage Test
Source

The Duct Blaster Tests

Part 1 - Pressurized Duct Test

Next we move to duct performance.  To perform this test, covers are placed over all supply registers sealing the entire duct system.  The furnace cover is removed and a fan pushes air into the ductwork.  Hoses attached to the fan and to nearest supply register measure pressure.  The difference between the two pressures is converted to a leakage rate.  The higher the pressure, the more accurate the measurement. Typically, the pressure must be raised to at least 25 Pa to get the most accurate measurement.

Today's test indicates a leakage rate of 2350 cfm, but at only at a pressure of 3 Pa. The fan is unable to raise the pressure above 3 Pa.  In other words, the system is very leaky. 2350 cfm of air is being lost through leaks within the home's ductwork system.  Unfortunately, these results are more the norm than atypical.

Infrared camera KT-384
made by Sonel
Source 

Part 2 - Pressurized Ducts & House Test

Next, the ducts are pressurized at the same time the blower door fan pressurizes the house.  This requires reversing the fan direction so that air is blown into the house. The pressure within both is equalized and a gauge at the blower door fan measures the difference between the two fan rates.  The difference is converted to the rate of air leaking from ducts outside the thermal envelop.  In other words, this test measures the rate of air being leaked from ducts within unheated spaces like attics and crawl spaces.

Today's test indicates 186 cfm of air is being leaked through ducts that are located out side the thermal envelop.

Thermogram of two buildings.
Darker colors indicate
 cooler temperatures.
Source

Part 3 - Direct Measurement of Supply Register Pressure

The final test again pressurizes the supply duct system and pressurizes the entire house using the blower door fan.  In this test, however,  the difference in pressure between the blower door fan and the pressure taken at various supply registers throughout the house is compared.  For a good duct system, the differences will never be more than 2 Pa.

Today's home performs well.  The pressure difference at two 1st floor supply registers is measured at no more than 0.8 Pa.

Foam used to seal air infiltration
points at the rim board

Identifying Leakage Points

During the performance of the blower door test, a thermal imaging infrared camera is used to locate areas of air leakage. Pointing the device at surfaces within the home, the camera measures surface temperature differences.  On a cold winter day, where outside temperatures are hovering around 20 degrees and indoor temperatures are around 68 degrees, the camera reveals temperatures below 68 degrees in varying gradations of dark colors.  The darker the color, the colder the surface.  The colder the surface, the more likely the location is a source of cold air leakage.

Poorly sealed fireplace doors were a
 major source of air infiltration

Today's test reveals the fireplace doors, doors to an attached sun room and the headers over basement glass block windows as the greatest source of leakage.

Conclusion

With the ultimate goal of improving home energy efficiency, improving homeowner comfort and reducing homeowner utility bills,  more and more homes are going to be tested for air and duct leakage. Homeowners will expect architects to use tests as described above to push contractors to raise their own standards.  And let's be clear, the savings that can be achieved by a homeowner are significant.  And the same way buyers use MPG (miles per gallon) to gauge the fuel efficiency of cars, HERS ratings will begin to educate home buyers on home energy performance.

American Radiator & Standard Sanitary Corp.

I discovered this original cast iron boiler in the basement of an historic Detroit home.  Curious about how it operated, I did a little research.

Boiler systems operate simply:

1. A fuel like natural gas or oil is mixed with air and ignited inside the boiler.  (This boiler probably was fueled by coal and later converted to natural gas).

2. The water circulating through the boiler's heat exchanger is heated by the flame and combustion gases.

3. The heated water is circulated to radiators which heat the house.

Photo Credit



In order to maximize efficiency, the correct air and fuel mixture must be found.  In other words, finding the correct ratio between the amount of air and fuel added to the boiler will maximize the amount of heat transferred to the water. Three gases are generated during combustion: Carbon Dioxide (CO2), Carbon Monoxide (CO) and Oxygen (O2). Too much air generates unburned oxygen, which will carry heat up the chimney. Too little air means incomplete combustion which generates poisonous CO gas and soot (which will clog the heat exchanger). The correct ratio will transfer all the combustion heat to the water and generate only CO2.

Modern boilers are rated by their annual fuel utilization efficiency (AFUE).  In Michigan, code requires all boilers to have a minimum AFUE of 90%.  The above boiler's efficiency was probably between 56% and 70%.

Imprinted on the door of the boiler are the words "American Radiator and Standard Sanitary Company ".  Per the brief history recounted below, this dates the boiler to at least 1967 when the company renamed itself "American Standard", but my guess is that it is probably much older.

 Planning your home for health and comfort with American Standard heating equipment and plumbing fixtures. (1950)
Source

Brief History of American Radiator and Standard Sanitary (ARSS)

The history of ARSS begins in 1886 when Clarence Mott Woolley and his partner formed the Michigan Radiator & Iron Company of Detroit.  They would become makers of cast iron (rather than the more expensive steel) radiators.  The business immediately took off, introducing the world to radiant heat.  In 1891 the company merged with two other leading manufacturers of cast iron radiators, the Detroit Radiator Company and the Pierce Steam Heating Company of Buffalo, New York.  Woolley was only 28.

/

The Ideal fitter : American Radiators & Ideal boilers (1910)
Source

The company would weather the economic depression of the 1890s by expanding into European markets.  By the 1920s, 40% of its revenue was generated overseas.  After World War I, Woolley hired architects John Howells and Raymond Hood to design and oversee the construction of his new world headquarters which still towers over Manhattan.

American Radiator Building - NYC 2012
Jean-Christophe Benoist

By 1929, Woolley planned a merger of the four largest building products corporation in the US: --H.W. Johns-Manville, Otis Elevator, Standard Sanitary, and American Radiator.  He was only able to complete a merger with Standard Sanitary, the nation's leading supplier of plumbing products.  Hence the name American Radiator and Standard Sanitary was born.

During the Great Depression, the company's sales were challenged by new forced-air heating technology.  The company met additional challenges as World War II cut into its European profits and new "direct-to-you" stores sold products directly to the consumer.  But the storms were weathered aided by a building boom that began after World War II.

Planning your home for health and comfort with
American-Standard heating equipment and plumbing fixtures. (1950) (pgs. 26-27)
Source

But the company's survival also meant diversification into new markets such as industrial controls, plastics, heat-transfer equipment, and nuclear reactor construction.   To reflect this, the company changed its name in 1967 to "American Standard".

By the 1970s, the company was now moving away from its original heating business concentrating more on its railroad, truck brake, and mining equipment operations.

 First step to better plumbing and heating for your home. (1947)
Source

Finally during the 1980s, the company returned to its plumbing and air conditioning roots by selling off most of its unrelated businesses.  In 1983, it completed a merger with the Trane Company the largest commercial air conditioning products company in the United States.

In 2007, American Standard announced plans to break up its three divisions – plumbing, air conditioning and automotive products – keeping only The Trane Company. American Standard’s plumbing products – and its name – were sold to Bain Capital Partners, LLC, and the original American Standard changed its name to Trane. Later that year, Ingersoll-Rand Company Limited acquired Trane for $10.1 billion.

Quite amazing roots for a small Detroit radiator company that began in 1880s.

 

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Source: History of American Standard at Funding Universe

 

 

The Nation's First Hospital

I've spent the last week in the City of Philadelphia visiting the nation's first hospital, Pennsylvania Hospital.  Founded by Benjamin Franklin and Thomas Bond in 1751, most of the original building remains intact and has been incorporated into a new hospital campus that is part of the University of Pennsylvania health system.

Pennsylvania Hospital, 1811
William Strickland

 In 1800, the accomplished American painter Benjamin West, now living in Britain, was requested to create a painting honoring the new hospital.  He agreed and entitled his painting "Christ Healing the Sick in the Temple"  It was completed in 1811, but because of its popularity, West was forced to sell his painting to Britain's National Gallery for the largest some ever paid for a modern painting.

Christ Healing the Sick in the Temple, 1811 (Version 1)
Source 

Still wanting to forfill his original commitment to Pennsylvania Hospital, West recreated the painting with improvements.  The most prominent change is the addition of a "demoniac" in honor of the new hospital's treatment of the mentally ill.  The new painting was delivered to the hospital in 1817 and is currently prominently displayed in a modern wing connecting the original and new hospital buildings.

Christ Healing the Sick in the Temple, 1817 (Version 2)
Source

 

See if you can find the differences between the two paintings.

 

Timken Silent Automatic

Surveying the dark basement of a Boston-Edison historic home, I stumbled across a rusting indoor oil storage tank.  Stamped boldly on its front are the words "Silent Automatic Detroit".

With some research, I discovered that this was probably an old storage tank that accompanied a Timken Silent Automatic Oil Boiler system.  Equipped with the famous Wall-Flame Oil Burner, the oil fueled system was designed to out perform its hard-coal fired rivals. 

Timken 1946 Mailer (page 1)

A Schenectady Gazette advertisement from March 10, 1931 proclaims eight buying points:

1. A Product of a Great Engineering Organization 

2. Low Purchase Price 

3. Cheaper Grade of Oil (use #1 or #2 oil) 

4. Fuel Economy 

5. Save Cost of a Gas Pilot (with the slight up charge for an electric ignition) 

6. Hot Water Supply (system can supply both heat and domestic hot water) 

7. One Model for any Site Home (models for "modest homes" are the same as those installed in "more wealthy neighbors") 

8. Installation By Only Factory Trained Men 

Complete installation is listed at a depression era $335 (oil storage tank extra).

March 10, 1931 Schenectady Gazette Timken Advertisement

The boiler's only moving part was the Mono-Roto.  It "whirls tiny droplets of oil outward against the chromium-steel flame rim... In a few seconds after the burner starts, the flame rim becomes glowing hot ...[as] a blue-hot flame...  blankets the fire box walls for the quick transfer of heat."

Timken 1946 Mailer (page 2)

A division of the Timken-Detroit Axle Company, the 32 acre main manufacturing plant was located at 100 Clark Street in Detroit, Michigan.  Other plants were located in Jackson, MI, Oshkosh WI, Utica, NY, New Castle, PA,  Ashtabula, OH and Kenton, OH.

Abandoned Poetry

It can be strange sometimes stepping into empty homes that seem to be frozen at the time they were abandon.  I've come across furniture, photographs, record collections and even breakfast left on the range.  But one of the most interesting surprises are the notes and drawings that are scribbled on walls.

Last Thursday, I ran across this poem written on the bedroom wall of an abandon Detroit home...

-11-8-10 -

you can try to hide

the pain from your

friends and to make

others believed you

moved on.  But you

can never deny the

truth to the person

who has hurted

you the most is

still the person

you will always

choose to love

Robert + Cedies

4 eva till the world blows

Reviving Detroit's "Potato Patch Plan"



A seated Hazen Pingree 

overlooks Grand Circus Park

Detroit is in the midst of the worst depression in its history.  Its city treasury is almost empty.  Some 25,000 Detroit men are unemployed.  Huge swaths of land sit vacant after a predicted real estate boom instead becomes a bust.


The people elect a Republican mayor who promises to reform City government.  He promises to end corruption in city paving and sewer contracts.  He promises to reform a corrupt school board.  He dedicates himself to fighting privately owned utility monopolies by creating the municipally-owned Public Lighting Department.  He fights to reduce streetcar fares by threatening to also create a municipally owned streetcar system.  But chief among all of the new Mayor's accomplishments is a welfare program known as the "Potato Patch Plan" that launches him into national prominence.

Michigan's 24th Governor
Hazen Pingree in 1885
photo credit

Now at this point, you might be confused about exact what period in Detroit history I'm describing.  It's the year 1894 and Mayor Hazen Pingree continues his first term, serving a City deep within the grip of the Panic of 1893.  During this second summer of the panic, Mayor Pingree executes a plan which will systematically use vacant city land for gardens which will produce food for the city's poor.  He auctions his $1,300 prized horse for $387 to raise funds for the securing of 430 acres of vacant land.

The location of the Detroit's "Potato Patches"
from an 1894 government report
Image credit

The City's clergy and aristocracy vehemently opposed the program claiming that "unemployed men were too lazy to work", "they would steal one another's crops" and "potato bugs would invade the city".

A group of women heading out to a potato patch circa 1890
Photo credit

In the first year, 3,000 families applied to participate, but only 945 were accepted.  Each of these first lucky families was given a one-half acre plot.  By the end of the first year, roughly $14,000 worth of food was harvested.  In 1895 and 1896, 1,546 and 1,701 families were respectively accepted into the program.  In 1896, the value of food grown by participating families was estimated at $30,998, significantly more than the amount paid out by the City's poor commission.  The program was an unprecedented success and immediately silenced its critics.  That same year, Mayor Pingree cashed in on his political successes and won a campaign to became Michigan's 24th governor.

It seems clear that as urban agriculture grows in popularity as a way to re-activate Detroit's 4,484 acres of publicly owned vacant land, that Detroit's history can act as a guide.  Mayor Hazen Pingree has proven success.  Mayor Frank Murphy, whose 1931 Thrift Gardens program (modeled after Mayor Pingree's) has proven success.  In 2010, researchers at Michigan State University concluded that modern urban farming efforts "could supply local residents with more than 75 percent of their vegetables and more than 40 percent of their fruits—a boon for a city where many residents live in food deserts."

The difference between today's efforts and those of the past lies in their permanency.  Where in the past agriculture efforts subsided after economic conditions improved, today's urban farms may prove to be fixed in Detroit's landscape as economic conditions and population loses are unlikely to change.  But no matter what role urban farming plays in Detroit's future, Detroit's past contains stories of success that can be effectively used to silence today's critics and skeptics.

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1. Follow this link for more details on Mayor Hazen Pingree's "Potato Patch Plan."
2. Follow this link to Michigan State University's 2010 study Growing Food in the City: The Production Potential of Detroit’s Vacant Land (PDF)
3. Follow this link to more more information on Mayor Frank Murphy's "Thrift Gardens."