All:
We have all benefited through the years from Klaus' thoughtful articles, and I
welcome this one.
But though most of the work of our 49 year practice (five decades of making the superinsulated building shell the main piece of HVAC equipment) has been of wooden structures, there are concerns about some aspects of the AIA's acceptance of Codes' permitting frame multistory apartment blocks of five stories (over an incombustible platform with protection by fire sprinklers) .
For instance, even when the framing is covered with sheetrock, should there be no water in the sprinklers (valves turned off, area power outage, utility pumping failure) fires in these blocks are often catastrophic, with nearly every US City having watched the glow despite many fire companies "surrounding and drowning", for hours.
Even without a conflagration, open-web wood joist floor systems and the cracks and voids inevitable in nailing up a whole floor per week, provide a veritable insect interstate for crawling critters to spread, even as those enjoying legal ,"weed" in one apartment share the "wow, man" with heretofore abstaining neighbors. Also, cumulative shrinkage of the framing adds concern.
Then there is the veritable parade of the HVAC Industry's erratic history of
fighting the collection of forever AC coolants that diminished the ozone layer of
our atmosphere. R-22 clearly was the major culprit and it is now available only
in the black market at over $500 per pound, helping restore the ozone layer.
But, that industry and its regulators continue to change the design coolant,
obsoleting millions of relatively new AC split systems. That industry, with
no opposition from AIA that I know of, now advocates "Butane" as a coolant.
Is Butane not the flammable stuff in cigarette lighters ? No matter, saith the
Code folks, henceforth split AC systems will run the coolant lines up the
five frame stories to the condenser-covered roofs, in rated shafts so that
coolant line leakage fires will delay their spread until the residents can flee.
Those who actually install AC systems protest that coolant leakage is
most often found in the aluminum coils (evaporator on the inside, condenser
on the outside) which means flammable lighter fluid could permeate the
cooled airstream in the apartments.
Then there is the increasing reliance on computer control systems for
residential HVAC units. The computer industry's rapid obsolescing
of its latest thermostats and other system controls, mean that failing
component replacements become hard to find at any cost, meaning
that entire systems must be replaced by an industry that recently announced
a 20% increase in component costs.
One might ask where the "Firmness and Commodity" of Vitruvius' trio
of architectural characteristics has gone in this case.
One last sad thought . Look at Soviet era concrete flat slab apartment blocks
in Ukraine and Russia and how they have stood up to 100 pounds of Drone
high explosives, with few progressive failures of whole buildings. While individual apartments are subject to sometimes fatal destruction, one wonders if a terrorist drone, foreign or domestic, struck one of our five story blocks, what would the damage be ?.
John F. Corkill, Jr., FAIA