Secondary Author(s)
Parker, Danny; Klongerbo, Jon; Sonne, Jeffrey; Cummings, Jo Ellen
Report Number
FSEC-PF-289-95
URL
http://publications.energyresearch.ucf.edu/wp-content/uploads/2018/06/FSEC-PF-289-95.pdf
Keywords
HVAC; Buildings; Cooling, Air conditioning sizing; Contractor practices; Manual-J procedure; Oversizing air conditioners; Residential HVAC; Cooling systems; ACCA standards
Abstract
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 points by homeowners.
The contractors' most popular method of sizing for air distribution was an estimate based on square footage. The variation was considerable, with responses of 0.8 cfm/ft2 and 1.5 cfm/ft2 both being common. One in four respondents indicated using methods that lead to inaccurate results. Some of the respondents chided others that size on square footage while others were critical of the Manual J method. A few respondents indicated their dissatisfaction with contractors who oversize systems, while others protested that undersizing is often done in order to achieve the low bid. Quoted comments of respondents are included throughout the paper.
Date Published
8-29-1996
Identifiers
767
Subjects
Air conditioning; Dwellings; Building fittings; Surveys; Buildings--Standards
Local Subjects
Buildings - Cooling; Buildings - HVAC
Type
Text; Document
Collection
FSEC Energy Research Center® Collection
STARS Citation
Florida Solar Energy Center and Vieira, Robin, "How Contractors Really Size Air Conditioning Systems" (1996). FSEC Energy Research Center®. 767.
https://stars.library.ucf.edu/fsec/767
Included in
Rights Statement
Notes
Reference Publication: Vieira, Robin K., Danny S Parker, Jon F. Klongerbo, Jeffrey K. Sonne, Jo Ellen Cummings. "How Contractors Really Size Air Conditioning Systems." Presented at the 1996 ACEEE Summer Study on Energy Efficiency in Buildings. American Council for an EnergyEfficient Economy, 1001 Connecticut Avenue, Washington, DC.