A blower door is a diagnostic tool used by builders, HVAC technicians, home energy auditors, and weatherization professionals to measure air tightness in a home and find air leaks.  According to Fine Homebuilding, blower doors are probably the most important building diagnostic tool.  I enjoy using the tool for the following reasons listed by the EPA:

• Reducing energy consumption from excess air leakage

• Avoiding moisture condensation problems

• Avoiding uncomfortable drafts caused by cold or warm air leaking in from outside

• Controlling outdoor contaminants, pests, and odors from entering your home.

• Determining proper sizing and airflow requirements of heating and cooling equipment.

• Determining whether mechanical ventilation is needed to provide acceptable fresh air and maintain indoor air quality in your home.

Like many places, Findlay is an area known for flooding and having less than stellar drainage.  A homeowner was fed up with flooding in their backyard, which caused some foundational problems.  I designed a plan to solve the root of the issue-excess water in the yard.  After implementing the new drainage system, there has been no flooding in this yards in the past couple years.  After heavy rains, you can now walk in this yard without sinking and the neighbor's higher-elevated yard is soggy.

Optimal radon mitigation involves air sealing and creating negative pressure under the basement flooring.  This can involve a mixture of crawl space encapsulation, sealing penetrations where radon and moisture wick indoors, measuring pressure differentials with a micromanometer, and using the most efficient inline fan to not incur an energy penalty by removing conditioned air.  The word "optimal" has been attached when an installer optimizes each of these variables.  Being a proponent of optimal mitigation systems due to the reduction in radon and moisture in homes (as well as having interest in such mathematical building problems), the install pictures provide evidence of significantly lowered radon levels (long-term 14.43 to 1.56 pCi/L day average).  The lower pictures were taken during a flood warning to demonstrate low relative humidity in the basement after the air sealing. I updated a non-working system with two crawl space encapsulations, basement crack fillings in slab, loads of basement air sealing, and adding a suction point in each of the crawl spaces.  Update:  The 15 pCi/L yearly average has reduced to around 1 pCi/L average over the past several months.  

Here is an article that I wrote about lowering water temperature and other factors to consider when retrofitting an existing boiler.  The article also deals with the possibility of adding a very efficient indirect tank for domestic hot water (the hot water in your house).  It includes design aspects and provides examples of retrofitting a midcentury 1950s system.