Saving Energy Costs

Earlier this month, Ron Zmyslo visited Huntington to present “It’s not the 1970s Anymore: How to Really Save Energy Costs in Your Historic House.” As part of the workshop, he also conducted a blower door test demonstration at a house being rehabilitated by Pathfinder Services, Inc.

About Ron Zmyslo

Ron has been in the building industry for over 45 years and is an alumnus of Ball State’s Master of Science in Historic Preservation program. He now is Construction Manager for the Indiana State Museum and Historic Sites. There he oversees the restoration and maintenance of the state’s 11 historic sites, which include over 100 structures, both historic and non-historic. As a consultant, his firm Preserve Restore Maintain Indiana has developed a number of workshops to equip historic and vintage building owners. He is also a certified weatherization auditor proficient in blower door and other energy efficiency testing.

Take-Aways from Ron’s Presentation

Ron began by talking about how most of our conventional wisdom about energy savings stems from efforts in the 1970s when things like dropping ceilings to reduce volume were promoted. Since that time, the field of building science has demonstrated that much of the conventional wisdom does not produce the desired cost savings–and just as bad, much of the conventional wisdom promotes the destruction of features important to the integrity and charm of historic structures.

Ron highly recommended Joseph Lstiburek’s website, Building Science Corporation (BSC), as a resource for quality information related to building science, including energy savings.

The Stack Effect

Ron spent quite a bit of time describing and demonstrating the physics of the Stack Effect. The BSC describes the Stack Effect as air movement caused by warmer air rising and colder air falling, which generates small but steady pressures in direct relation to the size of the temperature difference and the height of the column of air. The resulting pressure differences can lead to air leakage and generate unplanned air flows that result in indoor air quality problems within buildings.

Simply put, the stack effect creates a phenomenon in which air transfer occurs most predominantly at the bottoms (basements and crawl spaces) and tops (attics) of buildings. This goes against everything the replacement window industry would have you believe.

Source: http://heimlerheatcoolplumb.com/images/photos/stack_effect_grey_scale.jpg

With this knowledge, homeowner’s can focus on eliminating air infiltration in basements, crawl spaces, and attics to produce the greatest energy cost savings. These efforts may include weather-stripping windows, using a product such as Great Stuff to fill gaps and cracks, and adding insulation.

Ron also described how eliminating leaks at either the top or the bottom will prevent the stack effect–so if you do not have the ability or resources to do both, focusing on just one area (the attic or the basement/crawlspace) will do much to save energy.

Ron stressed that eliminating leaks first is important before investing in other important energy saving systems, such as high efficiency furnaces.

Comfort vs. Cost Savings

Another thing Ron emphasized is that there is a difference between loss of comfort and loss of energy. He used the example of a drafty window. The discomfort we feel from a window that is perceived as “drafty” is caused by the cold surface of the window pulling body heat off our bodies–and has nothing to do with energy loss! This discomfort can be easily remedied by simply adding a storm window or even a window treatment such as curtains.

Practical Steps to Save Energy Costs

1. Do this first! Eliminate leaks, especially at the top and bottom of the building. Close crawl space vents. Look for leaks at bypasses into attic (like plumbing chases) and side attics (usually found in houses with dormers). For balloon-framed houses, seal the top of all walls, both interior and exterior. Air seal band joist in basement/crawl space. Seal ducts and “bring inside” if possible by placing in insulated areas.
2. Insulate the attic, especially any side walls.
3. Install storm windows and weather-strip existing windows.
4. Replace low efficiency furnace with high efficiency unit.

Understand that good weatherization averages about a 25% savings in energy costs.

Visit the Energizing Indiana website to find out what programs are available to Duke Energy customers.

Blower Door Test Demonstration

The BSC describes a blower door as a machine used to test the air-tightness of buildings. A blower door is mounted in an opening and then uses a fan to pressurize or depressurize the measured space. The more airtight the space, the less air is needed from the blower door fan to create a change in air pressure.

For our demonstration, Pathfinder Services donated the use of 444 Henry Street, a house they are currently rehabbing in the Drover Town National Register Historic District.

444 Henry Street in the Drover Town Historic District

Ron set up the blower door in the front door opening. The fan is connected to an air pressure gauge, which is connected to a computer program that generates a report.

The blower door machine installed for the test.

Computer program generates a report detailing energy loss.

As the air is depressurized, it is possible to walk around and physically observe air being sucked in, around, and out of the house. Our test supported the theory behind the stack effect–demonstrating that air infiltration was mostly taking place in the basement/crawl space and attic.

In the basement, we found three major culprits of air infiltration:

A pane of glass had slipped in this basement window, sucking air into the house.

A huge stream of air could be felt traveling through this chimney clean out.

One of the places Ron recommended air sealing is the band joist in basements–air could be felt flowing in this gap.

On the first floor, we noticed air flowing up the door jamb from the basement.

Ron Zmyslo, pointing out air flowing up from the basement through a door jamb on the first level.

On the second floor, openings to attics, windows in need of weather stripping, and light fixture cut-outs proved to be sources of air loss.

Air could be felt flowing through windows on the second floor in need of weather stripping.

A door to the attic in a closet was pulling air through.

A door to a side attic was also pulling out air.

Air was being pulled through holes in a light fixture.

The blower door test demonstration was quite eye opening! It found that there was approximately 347 square inches of leakage area that costs $112 per year in heating and $22 per year in cooling.

Special Thanks

This program was made possible by a Historic Preservation Education Grant from Indiana Landmarks, Indiana Humanities, and the National Endowment for the Humanities. Additional lectures and workshops will be held this fall and spring.

St. Peter’s First Community Church hosted our workshop in their beautiful facility at no charge as part of the in-kind match for the grant. The church does a great job of opening their space to the community and we are so appreciative of their efforts in the Drover Town neighborhood.

Pathfinder Services donated the use of 444 Henry Street, one of the properties they are currently rehabbing, for our blower door test demonstration. We appreciate their eagerness to learn more about appropriate rehabilitation methods..