Around a decade or so ago a lot of things began to change in the world of residential HVAC (Heating, Ventilation and Air Conditioning). What I am going to discuss here is HVAC centric, but can apply across any industry where the government can (and does) make rules that on the surface mean “well” but in reality, just end up costing the consumer bucks$$$.
About five years or so, the manufacture of central air conditioners was mandated to be no less than thirteen SEER (Seasonal Energy Efficiency Rating). The previous minimum was ten SEER.
On the surface, this doesn’t appear to cause too many problems, besides cost the consumers more money on their initial installation, since the 13 SEER product cost more money (more raw materials to get that energy savings). Sadly, the engineering and physics (which can’t be mandated) told us different.
From an article by Michael Prokup (sorry can’t find the link):
Older evaporator coils operate at lower temperatures and pressures than modern evaporator coils.
Without getting into too heavy of an engineering discussion, this means that basically, the new 13 SEER units won’t work well with the old evaporator coils that sit on top of the furnace. The air conditioning cycle uses condensation and evaporation of a chemical (at this time, it was R-22) to move the heat from inside the house to the outside. Moving from 10 SEER to 13 SEER changed the whole game. No longer could a contractor come to your house and simply replace the outside condensing unit – now the evaporator had to be replaced, adding a lot of cost to the job – especially if the inside unit was sheetrocked into a closet, or was in some other type of area that was difficult to access. Apartment building owners were also affected by this.