PWM Control of a Cooling Tower in a Thermally Homeostatic Building

Peizheng Ma^1, , Lin-Shu Wang¹ and Nianhua Guo²

¹Department of Mechanical Engineering, Stony Brook University, Stony Brook, United States

²Department of Asian and Asian American Studies, Stony Brook University, Stony Brook, United States

Cite this paper:
Peizheng Ma, Lin-Shu Wang and Nianhua Guo. PWM Control of a Cooling Tower in a Thermally Homeostatic Building. American Journal of Mechanical Engineering. 2015; 3(5):142-146. doi: 10.12691/ajme-3-5-1

Abstract

Thermal Homeostasis in Buildings (THiB) is a new concept of building conditioning. Since summer cooling is the more challenging of building conditioning, several earlier papers focused on the study of natural summer cooling by using cooling tower (CT). The goal was to show the possibility and conditions of natural cooling, i.e., under what extreme day by day conditions that it is still possible for natural cooling to keep indoor temperature from exceeding a given maximum value: since no consideration was given to limiting indoor temperature above a minimum, in fact CT overcooling would be the problem for most part of the summer. This paper presents a fuller consideration of continual operation of a CT throughout the whole summer with pulse-width modulation (PWM) control of the tower operation. The goal here is to find to what extent the indoor temperature can be kept within the comfort zone. To put it another way, determine whether hours or percentile of hours out of total annual hours that the operative temperatures are out of the comfort zone are acceptable or not in a small sample of cities.

Keywords:
thermally homeostatic building building energy modeling PWM control cooling tower hydronic radiant cooling small commercial building

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