Retrotec USACE - Manual (Page 64)

42 ENERGY & PROCESS ASSESSMENT PROTOCOL
5.7.4 Level III Assessment
The Level III assessment consists of Level I + Level II + introduction of spe-
cial measurements (examples):
Tracer-gas measurements (infi ltration, air fl ows, ventilation effi ciency, etc.) ■
Air-fl ow monitoring (over a period of use or over a week) ■
Temperature monitoring, thermography of building and systems ■
Illumination/luminance measurements ■
5.7.5 Measuring On-Site
Measuring is usually time-consuming, and the energy auditor must determine
the reliability of the results and the added value for the assessment of energy-
saving potential. If rough calculation methods and tools are used for potential
assessment, accurate measuring may not improve the quality of the calculation.
On the other hand, if the whole potential assessment is based on estimates and
assumptions, the result is not very reliable.
The auditor should think carefully about what measurements are useful,
what results really indicate energy use, and which measurements are the most
time-consuming.
Temperature measurements are easy to make, but a thorough analysis of the
measured results and the measuring conditions is necessary to draw correct con-
clusions. These are some of the things that can have an effect on the measured
temperature: external and internal heat load (solar gain, equipment, lighting,
people), ventilation system, natural and uncontrolled ventilation, and so forth.
The auditor should make sure that his or her measuring equipment is cali-
brated regularly.
Depending on assessment type and aims, different levels of measurements
are needed. The main interest should be in key values and the most important
factors.
Even in a quick assessment the following issues should be roughly mea-
sured:
Boiler, chiller, and compressor operation temperatures ■
Room temperature levels in heating and cooling seasons ■
AHU temperature levels during heating and cooling seasons ■
Any simultaneous heating and cooling in AHUs ■
Nighttime and weekend setbacks in setpoints ■
The main cold and hot surfaces (building envelope heat loss) ■
A Level I energy assessment requires a limited kit of basic measuring in-
struments (e.g., air temperature, air humidity, and air velocity meters; airfl ow