Load Control Using Building Thermal Mass

2003 ◽  
Vol 125 (3) ◽  
pp. 292-301 ◽  
Author(s):  
James E. Braun
Keyword(s):  
Control Strategies ◽  
Field Studies ◽  
Commercial Buildings ◽  
Load Control ◽  
Thermal Mass ◽  
Widespread Application ◽  
Climate Conditions ◽  
Cooling Loads ◽  
And Control ◽  
Zone Temperature

This paper provides an overview of research related to use of building thermal mass for shifting and reducing peak cooling loads in commercial buildings. The paper presents background on the concept and the problem of optimizing zone temperature setpoints and provides specific results that have been obtained through simulations, controlled laboratory testing, and field studies. The studies have demonstrated significant savings potential for use of building thermal mass in commercial buildings. However, the savings are sensitive to many factors, including utility rates, type of equipment, occupancy schedule, building construction, climate conditions, and control strategy. The paper also attempts to provide an assessment of the state of the art in load control using building thermal mass and to identify the steps necessary to achieve widespread application of appropriate control strategies.

Impact of Precooling Control on Reducing Electrical Peak Demand for Commercial Buildings in Tunisia

2007 ◽  
Author(s):  
Nizar Khaled ◽  
Moncef Krarti
Keyword(s):  
Control Strategies ◽  
Commercial Buildings ◽  
High Mass ◽  
Time Shift ◽  
Thermal Mass ◽  
Peak Demand ◽  
Cooling Control ◽  
Simulation Based ◽  
Simulation Results ◽  
Cooling Loads

This paper summarizes the results of a series of simulation-based analyses to investigate the suitability of simplified pre-cooling control strategies in commercial buildings in Tunisia. The simulation results have indicated that pre-cooling building thermal mass during unoccupied period can provide a reduction of peak cooling loads as well as a time shift of when the electrical peak demand occurs during the day. The reduction in peak demand due to precooling controls was found to be more significant for buildings with high mass.

scholarly journals Effects of Animal, Climatic, Hunting and Handling Conditions on the Hygienic Characteristics of Hunted Roe Doer (Caprelous capreolus L.)

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1076
Author(s):  
Raffaella Branciari ◽  
Andrea Onofri ◽  
Fausto Cambiotti ◽  
David Ranucci
Keyword(s):  
Listeria Monocytogenes ◽  
Roe Deer ◽  
Control Strategies ◽  
Capreolus Capreolus ◽  
Careful Consideration ◽  
Salmonella Spp ◽  
Climate Conditions ◽  
Factors Affecting ◽  
And Control ◽  
Carcass Contamination

The population of wild animals is increasing, and control strategies based on selective hunting are among the major options adopted. The game meat obtained is therefore available for controlled and certified valuable chains. The understanding of carcass contamination and the factors affecting it is therefore crucial to ensure meat safety and prolonged shelf-life. The carcass hygiene of 64 hunted wild male roe deer (Capreolus capreolus L.) was evaluated in relation to factors potentially affecting it. Aerobic colony and Enterobacteriaceae counts, as well as Salmonella spp. and Listeria monocytogenes detection, were performed. The interaction of the microbial determination with age and weight of the animals, the climate conditions, the shooting procedure, the time between the killing and the evisceration as well as the time of storage of the carcasses in refrigerated conditions before skinning, were evaluated. Neither Salmonella spp. nor Listeria monocytogenes were detected on the carcasses and the average loads detected were 3.39 ± 1.06 UFC/cm2 and 2.27± 1.11 UFC/cm2 for the aerobic colony count and Enterobacteriaceae count, respectively. The loads detected are similar to those reported by UE legislation for slaughtered species. The time of storage before skinning, the environmental temperature during hunting and the time between shooting and evisceration, associated with animal weight, affect the carcass hygiene and must be taken into careful consideration by hunters as food business operators.

Growth, Reproductive Potential, and Control Strategies for Deeproot Sedge (Cyperus entrerianus)

2012 ◽  
Vol 26 (1) ◽  
pp. 122-129 ◽  
Author(s):  
Charles T. Bryson ◽  
Richard Carter
Keyword(s):  
Growth Rate ◽  
Field Study ◽  
Control Strategies ◽  
Reproductive Potential ◽  
Field Studies ◽  
Growth Chamber ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
And Control ◽  
Achene Production

Greenhouse, growth chamber, and field studies were conducted at Stoneville, MS, in 2000 to 2008, to determine the growth rate, reproductive and overwintering potential, and control of deeproot sedge. In growth chamber studies, deeproot sedge growth rate (ht) and plant dry wt were greatest at 25/35 C (night/day temperatures), when compared with regimes of 5/15, 15/25, and 20/30 C. Based on the average number of scales (fruiting sites per spikelet), spikelets per inflorescence, and culms per plant, deeproot sedge reproductive potential was 2.6-, 6.2-, and 17.4-fold greater than Surinam, green, and knob sedges, respectively. A single deeproot sedge plant produced an average of 85,500 achenes annually. Mowing at 15-cm ht weekly prevented achene production but did not kill deeproot sedge plants. The average number of inflorescences produced on mowed plants was 1.2 to 4 times greater in 2- and 1-yr-old deeproot sedge plants, respectively, when compared with unmowed plants. Mature deeproot sedge achenes were produced between monthly mowings. In a 3-yr field study, glyphosate, glufosinate, hexazinone, and MSMA provided more than 85% control of deeproot sedge, and above the soil, live deeproot sedge plant dry wt was reduced by 50, 64, 68, 72, 86, and 93% by dicamba, halosulfuron-methyl, MSMA, hexazinone, glufosinate, and glyphosate, respectively. All (100%) deeproot sedge plants 1 yr old or older overwintered at Stoneville, MS, at 33°N latitude.

Effects of Lighting, Zoning, and Control Strategies on Energy Use in Commercial Buildings

1995 ◽  
Vol 24 (1) ◽  
pp. 25-35 ◽  
Author(s):  
A. Mahdavi ◽  
P. Mathew ◽  
S. Kumar ◽  
V. Hartkopf ◽  
V. Loftness
Keyword(s):  
Energy Use ◽  
Control Strategies ◽  
Commercial Buildings ◽  
And Control

Anthelmintic resistance and novel control options in equine gastrointestinal nematodes

Parasitology ◽  
2018 ◽  
Vol 146 (4) ◽  
pp. 425-437 ◽  
Author(s):  
Ali Raza ◽  
Abdul Ghaffar Qamar ◽  
Khizar Hayat ◽  
Shoaib Ashraf ◽  
Andrew R. Williams
Keyword(s):  
Anthelmintic Resistance ◽  
Early Stage ◽  
Control Strategies ◽  
Field Studies ◽  
Gastrointestinal Nematodes ◽  
Feed Additives ◽  
Macrocyclic Lactones ◽  
Fecal Egg Count ◽  
Worm Control ◽  
And Control

AbstractControl of equine nematodes has relied on benzimidazoles (BZs), tetrahydropyrimidines and macrocyclic lactones. The intensive use of anthelmintics has led to the development of anthelmintic resistance (AR) in equine cyathostomins and Parascaris equorum. Field studies indicate that BZ and pyrantel resistance is widespread in cyathostomins and there are also increasing reports of resistance to macrocyclic lactones in cyathostomins and P. equorum. The unavailability of reliable laboratory-based techniques for detecting resistance further augments the problem of nematode control in horses. The only reliable test used in horses is the fecal egg count reduction test; therefore, more focus should be given to develop and validate improved methodologies for diagnosing AR at an early stage, as well as determining the mechanisms involved in resistance development. Therefore, equine industry and researchers should devise and implement new strategies for equine worm control, such as the use of bioactive pastures or novel feed additives, and control should increasingly incorporate alternative and evidence-based parasite control strategies to limit the development of AR. This review describes the history and prevalence of AR in equine nematodes, along with recent advances in developing resistance diagnostic tests and worm control strategies in horses, as well as giving some perspective on recent research into novel control strategies.

Advances in Near-Optimal Control of Passive Building Thermal Storage

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Gregor P. Henze ◽  
Anthony R. Florita ◽  
Michael J. Brandemuehl ◽  
Clemens Felsmann ◽  
Hwakong Cheng
Keyword(s):  
Optimal Control ◽  
Control Strategies ◽  
Thermal Storage ◽  
Thermal Mass ◽  
Commercial Building ◽  
Simulation And Optimization ◽  
Rate Structure ◽  
Starting Point ◽  
Utility Rate ◽  
And Control

Using a simulation and optimization environment, this paper presents advances toward near-optimal building thermal mass control derived from full factorial analyses of the important parameters influencing the passive thermal storage process for a range of buildings and climate/utility rate structure combinations. Guidelines for the application of, and expected savings from, building thermal mass control strategies that can be easily implemented and result in a significant reduction in building operating costs and peak electrical demand are sought. In response to the actual utility rates imposed in the investigated cities, fundamental insights and control simplifications are derived from those buildings deemed suitable candidates. The near-optimal strategies are derived from the optimal control trajectory, consisting of four variables, and then tested for effectiveness and validated with respect to uncertainty regarding building parameters and climate variations. Due to the overriding impact of the utility rate structure on both savings and control strategy, combined with the overwhelming diversity of utility rates offered to commercial building customers, this study cannot offer universally valid control guidelines. Nevertheless, a significant number of cases, i.e., combinations of buildings, weather, and utility rate structure, have been investigated, which offer both insights and recommendations for simplified control strategies. These guidelines represent a good starting point for experimentation with building thermal mass control for a substantial range of building types, equipments, climates, and utility rates.

scholarly journals Trombe Walls – Characteristic, Overview and Simple Case Study for Different Climate Conditions

2021 ◽  
Vol 943 (1) ◽  
pp. 012027
Author(s):  
A Oltarzewska ◽  
D A Krawczyk
Keyword(s):  
Thermal Comfort ◽  
Control Strategies ◽  
Climatic Conditions ◽  
Winter Period ◽  
Climate Conditions ◽  
Solar Systems ◽  
Simple Simulation ◽  
Trombe Wall ◽  
State Of Research ◽  
And Control

Abstract Currently, when we spend a significant part of the day indoors, paying attention to indoor air quality and thermal comfort rise to prominence. Sometimes, improving these issues could be really simple and possible by using passive solar systems like Trombe walls. Because the implementation of solar walls is still problematic due to numerous barriers connecting with a system management or effectiveness in summer or winter period, many of researchers try to find the solutions, which could optimize them. This paper characterizes the main issues of Trombe walls, presents the current state of research on solar walls and provides a simple simulation of a building with a Trombe wall performed in TRNSYS software, for 3 variants of the system and 4 locations with different climatic conditions. It was estimated that system with Trombe wall and control strategies allows the building to maintain thermal comfort for more than 20% of the year, but effectiveness of Trombe walls depends largely on the climatic conditions and they should be considered only as an auxiliary support for HVAC systems.

Advances in Near-Optimal Control of Passive Building Thermal Storage

2009 ◽  
Author(s):  
Gregor P. Henze ◽  
Anthony R. Florita ◽  
Michael J. Brandemuehl ◽  
Clemens Felsmann ◽  
Hwakong Cheng
Keyword(s):  
Optimal Control ◽  
Control Strategies ◽  
Thermal Storage ◽  
Thermal Mass ◽  
Commercial Building ◽  
Simulation And Optimization ◽  
Rate Structure ◽  
Starting Point ◽  
Utility Rate ◽  
And Control

Using a simulation and optimization environment, this paper presents advances towards near-optimal building thermal mass control derived from full factorial analyses of the important parameters influencing the passive thermal storage process for a range of buildings and climate/utility rate structure combinations. Guidelines for the application of, and expected savings from, building thermal mass control strategies that can be easily implemented and result in a significant reduction in building operating costs and peak electrical demand are sought. In response to the actual utility rates imposed in the investigated cities, fundamental insights and control simplifications are derived from those buildings deemed suitable candidates. The near-optimal strategies are derived from the optimal control trajectory, consisting of four variables, and then tested for effectiveness and validated with respect to uncertainty regarding building parameters and climate variations. Due to the overriding impact of the utility rate structure on both savings and control strategy, combined with the overwhelming diversity of utility rates offered to commercial building customers, the study cannot offer universally valid control guidelines. Nevertheless, a significant number of cases, i.e. combinations of buildings, weather, and utility rate structure, have been investigated, which offer both insight and recommendations for simplified control strategies. These guidelines represent a good starting point for experimentation with building thermal mass control for a substantial range of building types, equipment, climates, and utility rates.

An Integrated Dynamic Model and Control System for Activated Sludge Wastewater Treatment Plants Part II — Control Systems

1989 ◽  
Vol 24 (4) ◽  
pp. 497-522 ◽  
Author(s):  
Zdenko Vitasovic ◽  
John F. Andrews
Keyword(s):  
Process Control ◽  
Activated Sludge ◽  
Dynamic Model ◽  
Flow Rate ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Integrated Control ◽  
Field Studies ◽  
Pump Station ◽  
And Control

Abstract Part I of this paper has presented an integrated dynamic model for the activated sludge process consisting of a mixture of standard engineering equations and theoretical mechanistic models. In this, Part II of the paper, the integrated model is used in computer simulations to explore process dynamics and integrated control strategies. The interactions of six individual controllers: DO, MCRT, the STOUR profile, settler flow, the compressor, and a pump station have been studied as well as interactions between plant components and design and operation. Among these interactions are those between fluctuations in the influent flow rate and the solids-liquid separator and STOUR in each portion of the biological reactor. The use of a variable volume biological reactor is proposed to damp the effects of flow rate fluctuations on the separator and thus improve effluent quality. Estimation of the STOUR profile and its use in process control is proposed for producing a sludge with more consistent settling characteristics. It is proposed that the use of separator flow control, air flow rate distribution, and step feed capabilities for process control be further explored by field studies for possible incorporation in new plant designs.

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