Unfortunately, most furnace filters are slid in place without an airtight seal, which allows air to pass around the filters. This problem is worse for the higher-efficiency MERV filters because of the increase in air resistance.
Common Cause is a network of people working to help rebalance cultural values to create a more equitable, sustainable and democratic society. 1  We are all shaped by our culture.
Special causes = assignable causes = systemic causes = unstable & erratic = unnatural pattern of variability = variability outside the historical experience base. Common cause variability is institutionalized and accepted as thats the way things are. Special cause variability are sore thumbs that standout and are fixable. They are big surprises. They are exceptions to thats the way things are.