Agricultural and Biosystems Engineering Publications

Document Type

Article

Publication Date

2002

Journal or Book Title

Applied Engineering in Agriculture

Volume

18

Issue

2

First Page

245

Last Page

253

Research Focus Area(s)

Animal Production Systems Engineering

Abstract

An unvented liquid propane–gas (LP) space heater, often used in animal housing, was modified to provide automated variable heat output. As manufactured, the heater had manually–adjusted output settings between 14.7 and 29.3 kW (50,000 and 100,000 Btu/h). The heater was modified by adding a stepper motor and speed reducer to the manual proportioning valve to provide continuous and automated heater output adjustment between 14.7 and 29.3 kW.

Experiments were conducted to compare animal occupied zone (AOZ) velocities, AOZ temperatures, and fuel consumption using on/off and automated variable control modes. These experiments were conducted using inside set point and ambient air temperature differences of 14 and 28C (25 and 50F). All experiments were conducted in the Air Dispersion Laboratory at Iowa State University.

Adding automated variable control reduced the AOZ temperature fluctuations from 5.3C (on/off) to 1.1C (9.5 to 2.0F). In the AOZ, the standard deviation across the entire test room was reduced from 1.4C (on/off) to 0.3C (2.6 to 0.5F). The AOZ airspeed fluctuations were reduced from 10 cm/s (on/off) to 2 cm/s (20 to 4 ft/min). No differences were found in fuel consumption. Results indicate a need for heaters capable of continuous adjustment to even lower energy output levels.

Comments

Journal Paper No. J–18687 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project No. 3140, and supported by Hatch Act and State of Iowa funds

This article is from Applied Engineering in Agriculture 18, no. 2 (2002): 245–253.

Copyright Owner

American Society of Agricultural Engineers

Language

en

Date Available

December 10, 2012

File Format

application/pdf

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