Engineering Commons^™

How Contractors Really Size Air Conditioning Systems, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

This paper presents results from 489 of the 5559 Florida air conditioning contractors surveyed (an 8.5% response rate) regarding equipment sizing methods in new residences. Air conditioning sizing is accomplished by using ACCA's Manual-J procedure by 33% of the respondents, software by 34.4% of the respondents, square-footage by 24.2% and other estimate procedures by about 8.4%. Those using square-footage estimates varied from 350 square-feet- per-ton to 700 square-feet-per-ton. Over a third of respondents indicated oversizing intentionally on some jobs, in order to avoid complaints, accommodate future expansions, enable quicker cooling down of homes, and to allow for lower cooling set …

Are Energy Savings Due To Ceiling Fans Just Hot Air?, Florida Solar Energy Center, Patrick James

FSEC Energy Research Center®

Human comfort studies have shown that people prefer higher temperatures when they are subjected to a breeze. Ceiling fans are often used to create air motion in residences. Simulation studies (including one given in this paper) have demonstrated that in Florida, using ceiling fans combined with raising a home's temperature 2° F will generate about a 14% net savings in annual cooling energy use (subtracting out the ceiling fan energy and accounting for internally released heat). This savings drops to 2.6% with a 1° F increase in set point and to a negative 3.7% savings with only a 0.5° F …

Demonstration Of Cooling Savings Of Light Colored Roof Surfacing In Florida Commercial Buildings: Our Savior's School, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Architects and designers have long known that light-colored building roofs can reduce cooling needs. Recently, monitoring studies in Florida have made an effort to quantify these savings. Experiments in existing residences have shown that a white reflective roof can reduce cooling requirements by an average of 20%. However, until now there has been no investigation in Florida's climate to examine the potential in commercial scale buildings.

To remedy this need, a two year study was performed on a private elementary school building in Cocoa Beach, Florida. Our Savior's Elementary School was monitored for an entire year in a base line …

Measured Impacts Of Air Conditioner Condenser Shading, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

A study has been conducted by the Florida Solar Energy Center (FSEC) to examine if space cooling energy savings can be achieved from shading of residential air conditioning (AC) condenser units. The investigation consisted of before-and-after experiments conducted on three homes over a two year period. A recent EPA study recommends shading of exterior AC condensers, using landscaping or other means, as a method to reduce space cooling energy use (Akbari et al., 1992).

Side-By-Side Testing Of Commercial Office Lighting Systems: Two-Lamp Fluorescent Fixtures, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Lighting systems in commercial office buildings are primary determinants of building energy use. In warmer climates, lighting energy use has important implications for building cooling loads as well as those directly associated with illumination tasks. To research the comparative performance of conventional and advanced office lighting systems, Florida Solar Energy Center (FSEC) set up the Lighting Flexible Test Facility (LFTF) which allows side-by-side comparison of lighting options in two otherwise identical 2.7 m x 3.7 m (9' x 12') south facing offices.

The ceiling of the LFTF contains 0.61 m x 1.2 m (2' x 4') recessed fluorescent fixtures designed …

Uncontrolled Air Flow In Non-Residential Buildings, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

The objective of this study was to develop the capability to substantially reduce energy use, building degradation and indoor air pollution caused by uncontrolled air flow in nonresidential buildings. For purposes of the study, 'uncontrolled air flow' was defined as air moving across the building envelope or between zones or components of a building, where the pathways of flow, the direction of flow, and the origin of the air are unknown, unspecified, or unintended. The study comes to three major conclusions as follows: 1. Uncontrolled air flow is pervasive in buildings, often resulting in severe -- and sometimes even catastrophic …