With over 10,000 make-up air units sold annually, RuppAir understands the needs and requirements of our customers. We stand behind our systems, bringing 50 years of experience, unparalleled customer service and expert application support to each unique configuration.

RuppAir is uniquely qualified to handle the needs of our engineering customers. We provide instant to scale AutoCAD and PDF drawings for simplified system design and specification. RuppAir offers specific application guides with past expertise. We are committed to helping you configure and design a system that meets all of your needs while optimizing your return on investment.


SpecBuilder Specifying Software

AutoCAD & Revit Files:

Please contact your local sales representative for a project-specific AutoCAD (.dwg) or Revit file. Product submittal drawings can be found under the Resources tab of your specific product’s page.


RuppAir carefully takes all industry-standard safety codes into consideration to ensure a safe design for your client, including ASHRAE 62.1, and ANSI Z83.40.

Common Formulas

Technical White Papers:

Case Studies:

Cost Analyses:

Direct Fired vs. Indirect Fired Heating

Heated Make-Up Air Annual Cost Comparison

RuppAir offers a unique indirect fired unit with a constant 80% efficiency. By modulating both the gas and the air to the heat exchanger, a constant air to fuel ratio is maintained, resulting in energy savings for the user.

Project Location Minneapolis, MN
Quantity of Units 1
Heater CFM 8,000 CFM
Annual Heating Season Degree Days (Per Chart) 8,500
Average Winter Outside Air Temperature -7.6 °F
Cost of Electricity/KW-hr $0.11
Discharge Air Temperature 70 °F
Cost of Gas/Therm $0.61
Hours of Operation Per Day 18 hrs
Days of Operation Per Week 6
Days of Winter Operation Per Year 120 days
Data based on actual figures from Minneapolis, MN.

Indirect fired heater comparison

  Rupp indirect fired bent tube (IBT) Standard Indirect Fired
Average Daily Temperature - Heating Season (°F) 25 25
*Average Heating Season ΔT (°F) 45 45
Average Annual BTU/Hr Output Required 213.98 213,98
Average Annual Heat Exchanger Efficiency (%) Constant 80% 74.7%
Average Annual BTU/Hr Input Required 267,409 286,382
Total Therms Utilized/Year 8,664 9,279
Total Gas Consumption Cost/Unit $7,018 $7,516
Estimated Annual Cost & Energy Savings (%) 7%
Estimated Annual Cost Savings ($) $498
Estimated Life Cycle Cost Savings (15 Years) $7,470

Belt Drive vs. Direct Drive

RuppAir offers a wide variety of direct drive make-up and exhaust fans. These systems are not only easy to balance, but they require little maintenance and offer large energy savings by eliminating belt losses.

Contact Us