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Rooftop Unit Comparison Calculator
RTU Comparison Calculator   ( B E T A )
Welcome to the Rooftop Unit Comparison Calculator (RTUCC).

This calculator simulates the energy usage of both a high efficiency and a standard efficiency air conditioner. It then compares their energy and economic performance.

The RTUCC displays best in Mozilla Firefox. Good second choices for a web browser are Microsoft Internet Explorer and Google Chrome.

To run the RTUCC, characterize the two systems and their environment using the controls on this page. Then click the 'submit' button. Use your browser 'back' button to return from the results page to this control page or click on the "Return to Controls Page" link.

Use the 'restore' button to change all values back to the defaults shown in the far right column (more on defaults).

Move your cursor over a question mark near a controls name to display a help tip. Click on the question mark for more detailed information (more on help).

Visit the engineering methods pages for additional background information on the RTUCC. Click the version link (below) to view the revision history.
Advanced Controls Hidden
Show bin calculations Hide bin calcs
Building Type Office-Medium
State / City MO Kansas City
Schedule M-Fri, 7a.m. to 7p.m.
Indoor Temperature oF     Setback oF 75 oF Condenser Off
Total Capacity kBtuh    in stages 84 kBtuh in 2 Stages
Oversizing Factor % 0%
Candidate Unit EER  @  k$   $/yr 12 EER $4,500 $0
Enable Economizer Economizer enabled
Standard Unit EER  @  k$   $/yr 9 EER $4,000 $0
Enable Economizer Economizer enabled
Electric Utility Rate $/kWhrs 0.08 $/kWhrs
Discount Rate % 7.0 %
Equipment Life years 15 years
Number of Units units 1 unit
Version 4.2   ( B E T A ) Chart discounted costs Chart present value