Peter D. Zak, PE, Graef-USA Inc., Milwaukee

Articles

HVAC/R and Mechanical November 19, 2012

High on the energy hog

An example of a carefully planned successful energy and cost savings program was carried out by the Harley Davidson Motor Co. during the late 1990s.

By Peter D. Zak, PE, Graef-USA Inc., Milwaukee
HVAC/R and Mechanical November 19, 2012

Quick savings solutions

Design considerations like variable frequency drives are approaching the cost of motor starters, which allow for choices that weren't possible until now.

By Peter D. Zak, PE, Graef-USA Inc., Milwaukee
HVAC/R and Mechanical November 19, 2012

Economics of energy efficiency: Beyond ROI

Engineers and building owners often focus on payback periods and return on investment as economic decision-making thresholds for energy efficiency investments. However, there are other parameters that are more accurate and effective for investments in building systems.

By Peter D. Zak, PE, Graef-USA Inc., Milwaukee
Building Automation and Controls May 17, 2012

Whatever happened to critical thinking?

New engineers are brilliant and stupid at the same time.

By Peter D. Zak, PE, Graef-USA Inc., Milwaukee
Boilers, Chillers January 20, 2012

Control sequences for chilled water systems

The most important component of good chiller plant control is understanding the full and part load requirements and then matching those to system performance.

By Peter D. Zak, PE, Graef-USA Inc., Milwaukee
Other Building Types May 17, 2011

Airport gets a plant upgrade

Graef was commissioned in 1999 to design a new parking structure for General Mitchell International Airport in Milwaukee, but found the best location was on top of the existing chilled water and hot water power plant.

By Peter D. Zak, PE, Graef-USA Inc., Milwaukee
Other Building Types May 17, 2011

Choosing a chilled water cooling system

There are a variety of cooling systems that will meet the cooling requirements of a facility.

By Peter D. Zak, PE, Graef-USA Inc., Milwaukee
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