Room Air Conditioner Cost Estimator

Screen capture of Room Air Conditioner Cost Estimator

The cost estimator compares high-efficiency room air conditioners to standard equipment in terms of life cycle cost. It provides an alternative to complicated building simulation models, while offering more precision than simplified estimating tools that are commonly available. The cost estimator assists decision-making regarding the purchase or replacement of room air conditioning equipment, by estimating a product�s lifetime energy cost savings at various efficiency levels. Screen Shots


air conditioner, life-cycle cost, energy performance, residential buildings, energy savings


Internal reviews at Pacific Northwest National Laboratory.

Expertise Required

High level of computer literacy not required; estimator tool is web-based. Some knowledge of air conditioning technology is helpful.


Newly released in 2005.


Home owners, apartment tenants and building managers.


City, state, time schedules, indoor temperature, cooling capacity, oversizing factor, energy efficiency ratio (EER), purchase cost and maintenance cost for both the candidate and standard unit, electric utility rate, discount rate, and equipment life.


Tables and graphs of the product�s estimated lifetime energy cost at different efficiency levels, including results of internal calculations if desired.

Computer Platform

Fully web-based. Can be run on any platform that supports Microsoft Internet Explorer (version 5.0 and later) or Netscape (version 7.1 and later).

Programming Language

VBScript, JavaScript, HTML


The tool is web-based with a help feature available to provide details. By accounting for local climate and part-load operation, the tool offers more precision than simplified estimating tools that are commonly available. The results provide an easy way to quickly diagnose the feasibility of purchasing new equipment.


The Cost Estimator performs a detailed hourly bin analysis. However, this tool is not intended to replace dynamic hourly time-series simulations of buildings and their HVAC systems (such as those performed by BLAST and DOE-2). The Cost Estimators calculations are suitable for estimating and comparison purposes only.



Pacific Northwest National Laboratory


PO Box 999
Richland, Washington 99352
United States


+1 (509) 375-4398




Available at no cost through the RAC web site.