Attention Labs: Energy Rebate for Ultra-Low Freezers

Rebates range from $3,286 to $5,000, depending on the model purchased

By Trisha Dupnock and Randy Smith

On average, laboratories are five times more energy intensive than other spaces on campus. To incentivize faculty members to purchase energy efficient lab equipment, Duke Engineering faculty research labs are eligible for rebates to offset the cost of purchasing energy efficient ultra-low freezers.

The purpose of this communication is to inform faculty on the details of the rebate program so that they may make an educated freezer purchase that aligns with Pratt’s sustainability ambitions.

The rebate described below was emulated from a rebate program offered at the Trinity School of Arts and Sciences.

Table 1 below tabulates the cost of three, approved freezers, and the rebate amount Pratt has agreed to sponsor. Table 2 shows the energy consumption and cost savings (compared to a conventional, non-energy efficient freezer) associated with each freezer. For reference, the cost of a conventional freezer is about $9,000.

Table 1: Rebate Cost Breakdown



Purchase Price


Final Cost

Stirling Ultracold















Table 2: Energy and Cost-Savings Breakdown



Yearly Energy Consumption


10 -Year Savings

vs. Control

Stirling Ultracold










The data shown here were taken from an energy audit conducted by Duke Energy Manager Casey Collins and the EPA Energy Star program.

With the rebate, the Panasonic and Thermofisher models cost about the same price compared to the Stirling Ultracold, which costs about $2,500 more. Looking at the 10-year cost savings, the Stirling Ultracold and Panasonic freezers offer the greatest long-term cost savings.

In addition to electrical and HVAC energy cost savings, the Stirling model has no compressor, so the normal compressor rebuild after several years is not a consideration in this model.

This could amount to an additional $3,500 in cost savings, which would reduce the payback period.

Based on current user feedback, the Stirling Ultracold is the most durable of the three freezers.

To Participate

Contact Kelly Rockwell at