In this study, the air-side pressure drop and heat transfer performance of plate-fin and microchannel coils were tested under clean and fouled conditions. The heat exchangers were tested with two different types of dust, ASHRAE dust and Arizona Road Test Dust. The ASHRAE dust was found to have a very significant impact on the pressure drop of the microchannel heat exchanger, increasing the air-...

In order to avoid the inherent aerodynamic difficulties of the conventional fume hood, an innovative design--the 'air curtain-isolated fume hood' is developed. The new hood applies a specially designed air curtain (which is generated by a narrow planar jet and a suction slot flow at low velocities) across the sash plane. The hood constructed for the study is full size and transparent for flow v...

The selection Selecting the right of a thermal comfort model for establishing optimal indoor optimal hygrothermal conditions during the hot period has a major impact on energy consumption of Net Zero Energy Buildings in hot climates. The objective of this paper is to compare the influence of using different thermal comfort models for zero energy buildings in hot climates. The paper compares the...

Selecting the model is an important and essential step in model based fault detection and diagnosis (FDD). Factors that are considered in evaluating a model include accuracy, training data requirements, calibration effort, generality, and computational requirements. The objective of this study was to evaluate different modeling approaches for their applicability to model based FDD of vapor comp...

ASHRAE Technical Committee (TC) 9.9 Mission Critical Facilities, Technology Spaces, and Electronic Equipment published a white paper in 2009 entitled Gaseous and Particulate Contamination Guidelines for Data Centers. That paper has raised concerns with data center designers and operators by stating that there is a recent increase in IT equipment failures associated with airborne pollutants. Whi...

ANSI/ASHRAE/IESNA 90.1 Energy Standard for Buildings except Low-Rise Residential Buildings is the benchmark code of U.S. local regulations. In addition to provide a set of minimum mandatory requirements for energy-using components (prescriptive approach), the standard includes in the Appendix G a more flexible path to attest performances significantly better than code minimum (performance-based...

The required length of vertical ground heat exchangers (GHX) used in ground-coupled heat pump (GCHP) systems is determined so that the outlet temperature from the GHX remains within certain limits for the worst ground load conditions. These conditions may not necessarily occur after 10 or 20 years of operation, as is usually assumed, but often occur during the first year of operation. The prima...

This experimental study investigates the advantage of using Mn–Zn Fe2O4/water ferrofluid subjected to effect a non-uniform magnetic field on thermal efficiency fabricated cylindrical solar collector with receiver in shape helical pipe. Using ASHRAE Standard, this has investigated influence nanoparticles volume fraction (0.0–1.0%), mass flow rate fluid (0.00415–0.033 kg/s), and produced by set p...