| Cooling system problems often emanate from the differences
between three perspectives: The phrases: "as drawn," "as built," and "as
operated," indicate these differing viewpoints representing the system
designer, the builder or installer, and the system operator.
"As drawn" highlights the designer's perspective. Here, the emphasis is
often on designing the building to a given budget. Typically amenities and
other perceived "moneymaking" equipment have budget priority over the
"money-using" HVAC equipment. Even so, the design community will often
specify relatively sophisticated HVAC systems. However, the designer's
assumption is that the building owner is familiar with the HVAC design and
will implement the system as designed. And, in all too many cases, the
designer is forced to specify the HVAC system without regard for life-cycle
costs.
Then the building owner exerts pressure, and as budgets are cut or
shifted and the originally-specified equipment is delayed, finishing the
building takes on a higher value. The worst case is "warehouse" engineering
where the contractor will substitute whatever is available in the warehouse
for the original design. Unfortunately, these compromises and changes are
seldom documented and often fail to even work up to their capability as the
contractor tinkers with system settings to avoid callbacks. For example, it
is much easier to set supply air temperatures low and use reheat to correct
unbalanced zones. (It's also much more costly to the building owner).
The operator now enters the picture. They will often aggravate the
situation and compound the problem because no one ever trained them in
efficient building operation. In fact, they're seldom rewarded for the
cost-savings impact they can have associated with efficient building
operation. The result is predictable: they respond first to "hot calls" and
"cold calls" and learn to set controls or even bypass intrinsic energy
efficiency features to avoid even getting these calls in the first place.
The result is a predictable and steady degradation in system performance.
Utilities, often with a little encouragement from their regulatory
agencies, realize HVAC design and operation are important elements in
building energy use. Utilities realize design and operation can
significantly impact energy efficiency and demand side management programs.
Unfortunately, building owners or developers seldom share this viewpoint.
Therefore, when a utility is able to assume at least an advisory role in
building design and system operation through the design phase and various
retrofit programs, they can promote energy efficiency and help assure a
positive outcome.
|
