Jason Woods

Development and Analysis of Desiccant Enhanced Evaporative Air Conditioner Prototype

This report documents the design of a desiccant enhanced evaporative air conditioner (DEVAP AC) prototype and the testing to prove its performance. Previous numerical modeling and building energy simulations indicate a DEVAP AC can save significant energy compared to a conventional vapor compression AC (Kozubal et al. 2011). The purposes of this research were to build DEVAP prototypes, test them to validate the numerical model, and identify potential commercialization barriers.

Combining liquid desiccant dehumidification with a dew-point evaporative cooler: A design analysis

This article uses a numerical model to analyze a concept combining a liquid desiccant dehumidifier with a dew-point indirect evaporative cooler. Each of these components, or stages, consists of an array of channel pairs, where a channel pair is two air channels separated by a thin plastic plate. In the first stage, a liquid desiccant film lining one side of the plates removes moisture from the process (supply-side) air through a membrane. An evaporatively cooled exhaust airstream on the other side of the plastic plate cools the desiccant. The second stage sensibly cools the dried process air with a dew-point evaporative cooler. This article uses a parametric analysis to illustrate the key design tradeoff for this concept: device size (a surrogate for cost) versus energy efficiency. The analysis finds the design parameters with the largest effect on this tradeoff and finds the combinations of design parameters giving near-optimal designs, which are designs with the highest efficiency for a given device size. The results indicate that there are two key parameters contributing to this tradeoff: the supply-side air channel thickness and the exhaust-air flow rate in the evaporative cooler.

Frequency Regulation Services from Connected Residential Devices: Short Paper

This paper demonstrates potential benefits that residential buildings can provide for frequency regulation services in the electric power grid. In a hardware-in-the-loop (HIL) implementation, simulated homes and a physical laboratory home are coordinated via a grid aggregator, and it is shown that their aggregate response has the potential to follow the regulation signal on a timescale of seconds. Connected (communication-enabled) devices in the National Renewable Energy Laboratorys (NRELs) Energy Systems Integration Facility (ESIF) received demand response (DR) requests from a grid aggregator, and the devices responded to meet the signal while satisfying comfort bounds and physical hardware limitations. Future research will address the issues of cybersecurity threats, participation rates, and reducing equipment wear-and-tear while providing grid services.

Grid Connected Functionality

Dataset demonstrating the potential benefits that residential buildings can provide for frequency regulation services in the electric power grid. In a hardware-in-the-loop (HIL) implementation, simulated homes along with a physical laboratory home are coordinated via a grid aggregator, and it is shown that their aggregate response has the potential to follow the regulation signal on a timescale of seconds. Connected (communication-enabled), devices in the National Renewable Energy Laboratorys (NRELs) Energy Systems Integration Facility (ESIF) received demand response (DR) requests from a grid aggregator, and the devices responded accordingly to meet the signal while satisfying user comfort bounds and physical hardware limitations.