A HOME COMFORT RETROFIT: THE BOB MARCH RESIDENCE

A HOME COMFORT RETROFIT CASE STUDY: THE BOB MARCH RESIDENCE
South Reno, Nevada

Bob March of Reno called us to perform an energy audit on his newly purchased home in south Reno. He was concerned about comfort and energy efficiency. We solved his problems and in the process lowered his energy bills.This is the story of Bob’s home:

Age of Home: 30 years
Square Feet: 2,100
Purchased: 2003

When Bob purchased the home, he was advised by seller that the house used about 300 gallons of oil per month during the heating season.

PROBLEMS HE EXPERIENCED AFTER MOVING IN

• Rear bedrooms and bath colder than the rest of house; drafts
• High energy bills
• Drafts in the kitchen
• Whistling noise at the return duct when furnace was operating

WHAT ENERGY MASTERS DID FIRST

1. We performed a blower door test to determine air infiltration rates in the home and identify air leakage sites.

2. We performed infrared camera scan to find cold areas.

3. Performed an efficiency analysis on the furnace and air distribution system.

4. Visually inspected the attic and crawl space.

5. Because the house is located on granitic soils, performed simple charcoal canister, 48-hour Radon test.

WHAT WE FOUND

Random air infiltration through the home was not severe but enough to cause comfort problems. Heated air escaping at the top of the house pulled in cold air from lower level cracks and holes, including from the crawl space. The problem was magnified when the furnace fan was running. Air intruding into batt insulation also reduced its R-value.

A. The Attic Hatch: The unsealed, uninsulated attic hatch allowed heated air to escape into the attic and beyond. Cold air shows up as dark ble or purple in this infrared photo.

B. The Recessed Lights: Cold air in the attic around this recessed light was captured as dark blue or purple in this infrared photo. This light was located in a dropped soffit which was open to the attic and uninsulated.

C. The Fireplace Chimney: This had a large open chase around it at the attic floor.

D. Pipe and Wire Openings: Penetrations under the sink allowed cold, polluted air from the crawl space to enter the living area. Wire penetrations and other pipe openings were unsealed in the attic.

E. Register Ducts: The register ducts indicated duct leakage.

F. Return Ducts: A return duct was disconnected from the grille in the living room.

G. Missing Insulation: There were R-19 fiberglass insulation batts on the attic floor with a smattering of blown-in fiberglass on top. Because of gaps, voids and air intrusion into the insulation, it was functioning well below the nominal R-19, which is half the recommended level of R-38. Following are examples of missing insulation as well as holes between the atttic and living space.

H. Supply Ducts: Supply ducts located in the crawl space were not sealed or insulated. An estimated 30% of all heated air was being lost to the crawl space. Dirty insulation around the ducts indicated where air was leaking out.

I. Vapor Barrier: The vapor barrier on the crawl space floor was for the most part missing.

HOW ENERGY MASTER FIXED IT

1. We sealed all penetrations and holes between living space and crawl space and living space and attic.

2. Reconnected return duct in the attic and caulked around the penetration where the grille met the drywall.

3. Weatherstripped and insulated the attic.

4. Installed air tight trim to recessed light. Bob later underwent a remodel in a portion of his home and took our advice of installing IC rated (insulation compatible) recessed lights with air-tight trims, caulked to the ceiling drywall.

5. Sealed dropped kitchen soffit at the attic floor.

6. Installed cement board and fire-rated caulk over open chases around fireplace chimney in the attic.

7. Blew in cellulose over existing insulation to achieve a settled insulation depth of R-38.

8. Sealed all duct connections and plenums with water-based mastic and fiber mesh tape then insulated with R-8 duct insulation.

9. Applied metal tape to openings between floor and duct registers.

10. Installed 6 mil plastic on crawl space floor to prevent the wicking up of moisture from the soil into the wood framing members of the home. It also helps to encapsulate pollutants under the barrier and prevents them from being transported into the home through leaks in the duct system.

FINAL RESULTS

1. Drafts disappeared.

2. Back rooms maintain the same temperatures as the rest of house.

3. Whistling noise disappeared around return grille.

4. Energy use dropped dramatically.

Bob used approximately 50 gallons of oil a month to heat the home during the 2007-08 season, even after installing a five gallon oil-fired water heater! That is 250 gallons less use than reported during the previous heating season!

Update: Between September 2008 and February 2009, Bob used only 200 gallons of oil. This comes to $40 per month!