Residential Comfort & Energy Efficiency

Duct leakage inside a home can account for as much as 30% of energy loss.  But, how do you fix a problem that mostly lives behind walls and in hard to reach locations?

Most homeowners that have a knee wall in their home don't know they have a knee wall in their home.  This article discusses the different type of knee walls, the issues knee walls present in terms of comfort and energy efficiency and how to properly treat knee walls for peace of mind.

Common Construction Philosophies

Maryland crawl spaces can be a giant source of comfort issues in summer months.  Crawl spaces are typically intentionally connected to the outside humid air with vents around the foundation wall.  The idea was that installing vents will create ventilation.  Unfortunately, due to pressure dynamics that in many ways are related to meteorology pressure highs and lows, the air in the crawl space becomes more humid and damp and issues are compounded with the steady infiltration of stale, humid air.  If there are ducts running through a crawl space it is more important to consider what measures can be taken to treat the crawl space.  Spending a little money up front on crawl space encapsulation will save much more money in the long run if you consider duct leakage, overworking HVAC equipment and extra infiltration of warm, humid air in summer and cold, dry air in winter. 

Check out this before and after crawl space encapsulation project with blocking and sealing open vents.

Crawl Space Encapsulation Maryland - Smart Thinking
In the simplest terms, to encapsulate a crawl space is cutting it off from the outside air.  When I was young we had the Weather Channel that was just a table with today's temperature and conditions and it would cycle through each city in the U.S.  San Diego, no matter the time of year it seemed, was always 70 degrees and sunny.  We want the crawl space to be 70 degrees all year round - without the sun, of course.  By doing so, you are bringing the space into the "envelope" of your home.  If ducts exist in the crawl space, the ducts don't have to work as hard to service the rooms above. 
 

Overall, the HVAC system is asked to do less as a result of crawl space encapsulation and yet the inhabitants are more comfortable.  

Imagine if that was a formula for everything in life.  Work less and gain more!

Learn more about common sources of home comfort issues.

Hometrust Remodeling recently completed an insulation job in Laurel, MD 20723.  The project consisted of the following measures:

• Air seal the attic floor
• Install soffit baffles at eaves for ventilation
• Cut soffit holes to add air intake for attic ventilation
• Seal 4 recessed lights
• Add 10" of loose fill blown cellulose insulation
• Treat the main attic access hatch
• Treat the garage attic to encapsulate the space
• Sealed accessible HVAC duct connections

For most insulation to be effective it is important to stop the flow of air by sealing up holes and cracks in as many accessible areas as possible. 

Insulating the accessible skylight kneewalls to R13 after sealing smaller crevices/cracks and adding sheathing (air barrier) over the insulation will maximize boundary effectiveness and reduce air communication between the living space and the attic (outside).

                                 
Completed attic insulation & skylight kneewall 20723                                      Garage roof encapsulation in Laurel, MD                   

Most of the largest leaks in homes occur where framing (such as floor joists or wall studs) span from an area inside conditioned space to an unconditioned or vented space, such as the attic,crawlspace, garage, or roof. Appropriate blocking is needed in these instances.

Untreated recessed lights are invisible gateways for air to communicate between the inside (conditioned space) and outside (attic).  Covering and sealing accessible recessed lights will eliminate this issue.

Encapsulation, using open cell spray foam, was completed for this project so that the space below, including the HVAC unit in the garage attic, would become part of the overall "envelope".  The garage is going to be converted to living space (in-law suite) so by encapsulating the area above the space, it will make it easy to complete the job once the work gets done and when the space is changed, the HVAC will also benefit from being enclosed inside the house rather than outside (garage attic).