Post War California Tract House Energy Audit Reveals Room for Improvement

Postwar, 1947 tract house on 1/3^rd acre lot is inundated with sun since the old trees died. The owners are doing a remodel. West facing single pane windows let in ample sun and warmth on a February 1^st afternoon. By April or May it will surely feel like a furnace. New, California Energy Code level windows formulated for western orientation will make the dining/living room more comfortable year-round.

The house has no insulation in the floor or walls. The ceiling has about 3 ½ inches of old, disturbed, blown in insulation. Building a dam around the fold-down access stairs and furnace and insulate it to R40 (about 14 inches of blown-in cellulose) would make the place far more comfortable and cause the furnace/AC to run less often.

The attic access is an area where warm conditioned air escapes to the attic, causing drafts and wasted energy dollars. Those fold-down access stairs to the attic are really hard to air seal or weatherstip properly. I suggest adding on one of the zip-up “tents” that go on top of the access area.  I’d never seen one until last fall. They are air tight and really work.  Check out one site selling such “tents”, http://www.energyefficientsolutions.com/attic-tent.asp

That same attic, under a brown roof must surely bake in the summer sun. I suggest adding radiant barrier under the roof deck. You really have to feel the difference to believe how much energy this material stops from radiating into the attic. It works! Check out http://energy.gov/energysaver/radiant-barriers  to learn more. For a low tech way to go, here just paint the roof white. They do it from the Bahamas to India to the Greek Islands. Put on your sunglasses and check out Santorina, Greece, cool…
 

The crawlspace is open and ventilated to the outside with no insulation in the floor. Many would suggest adding R19 fiberglass  insulation to the bottom of the floor. That is an imperfect way to go. A more interesting and healthy option is to encapsulate the crawlspace. This action can not only keep the floor warmer in the winter but keep the nasty air from the crawlspace out of the house. I’ve read articles stating that over 40% of the air in a house comes up from the crawlspace. Below is a before and after pic that shows the visual improvement. The lower pic shows how a crawlspace can become a semi-conditioned sub-first floor that seems more like an operating room than a crawlspace.

il. Above Left: Thick plastic separates house from soil
Right: Americover.com materials encapsulate crawlspace

The water heater is a standard .62 tank water heater that takes up a significant amount of space in the garage. The owner mentioned how an expanse of pipes makes the cold water hot in the summer months.  An upgrade to an instantaneous gas water heater could both free up space and provide energy savings.  The pipes could be insulated to reduce heat gain.
Takagi Instantaneous gas water heater saves space and energy

The house has a newer large furnace/air conditioner system that appears to be well sealed except for a small leak on the right hand side of the furnace. Place UL 181 aluminum tape on the corner of the plenum to seal it.  The flex ducts appear thoughtfully sealed however they all leak unless there is mastic on the joint of duct to the plenum. Twelve dollars worth of air duct mastic and an hour spreading it around every duct connection would surely keep more air inside the system and the house rather than in the attic.

Doing the above items would render the house more comfortable and lower the energy bills. How much? To learn that, computer energy modeling is necessary. Your energy consultant could easily model them and assign dollar values.  The nice thing about the upgrades is that they offer non-energy dollar benefits of  improved air quality, added space and improved thermal comfort.

Building Energy Compliance Testing

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