The efficiency ratings of heating and cooling equipment are an essential aspect of its selection, approval, and installation in the United States, as required by law. These efficiency ratings aren’t just linked to the units’ energy use; they also determine whether a system can be sold, installed, or operated in accordance with federal law. Recently, an independent review has raised concerns about the Designline brand. Designline air conditioner and heating systems, particularly models MHP10 and MHP11, are raising concerns about their compliance. The reviewer claims that these HVAC systems do not meet the Department of Energy (DOE) requirements, are misclassified in the wrong product category, and are listed with inaccurate performance numbers. Let’s cover the details of this review.

The Designline HVAC Unit Fails To Meet Minimum Efficiency Requirements

Federal energy regulations require SEER2 and HSPF2 ratings for heat pumps in the AHRI 210/240 product category. The Department of Energy (DOE) has specified that heat pumps with a nominal cooling capacity of 10,000 BTU must have a minimum efficiency of 13.4 SEER2 to be sold or installed in the U.S.

Third-party analysts claim that DesignLine HVAC models—MHP10 and MHP11—have not released any certified SEER2 or HSPF2 values. DesignLine hasn’t published the SEER2 values for its units, as they failed to meet the required 13.4 SEER2 value when tested in a certified laboratory, rendering the units illegal to sell or install in the United States.

Illegal Product Classification

Designline Cooling Systems and heating units—MHP10 and MHP11—are classified as Packaged Terminal Heat Pumps (PTHPs). However, the law requires PTHPs to have the following physical features:

• A self-contained, through-the-wall mounting design.

• A wall sleeve.

• A separate unencased chassis (installed into a wall sleeve and cabinet, without having its own dedicated outer casing).

Designline’s units—MHP10 and MHP11—don't have these features, making them ineligible for classification as PTHPs. In addition, they have used the EER rating instead of SEER2 to again classify the models as PTHPs (which they aren’t). This violates the U.S. Department of Energy (DOE) rules and makes the classification improper.

Wrong Rating Metric Used

Reviewers claim that DesignLine is using the wrong rating metric—EER for cooling and COP for heating—to classify and market its products as Packaged Terminal Heat Pumps (PTHPs). The federal law, under AHRI 210/240, requires brands to publish SEER2 for cooling efficiency and HSPF2 for heating efficiency for this product category. According to the claims, the missing SEER2 data may be intentional because the unit would fail to meet the bare minimum efficiency standards, making it illegal.

Efficiency Failure

Even assuming the DesignLine’s two units as Packaged Terminal Heat Pumps (PTHPs), they still fail to meet the minimum efficiency criteria as set by the law. The federal minimum PTHP EER for this size class is 10.4 EER. The published data suggest that DesignLine does not meet this legal standard, implying that the units are illegal to manufacture, sell, or install in the U.S.

Inaccurate Performance Numbers Listed Deliberately

The reviewers have also raised concerns about the questionable performance numbers for DesignLine Roommate MHP10 and MHP11. DesignLine lists the heating capacity as 11,200 with a 3.5 COP, whereas the manufacturer, Nordica, has published only 9,000 BTU at 3.1 and 3.4 COP. After recalculating these numbers using standard methods to determine the efficiency, the results are inconsistent and variable.

Final Insights

Based on the lab findings and the claims in the review, the DesignLine Roommate MHP10 and MHP11 units do not comply with U.S. federal efficiency requirements. In the absence of SEER2 and HSPF2 ratings, these units cannot be verified as legal for manufacture, sale, or installation in the U.S.

For users, operating these units with inaccurate data could lead to higher energy bills and other serious issues. Contractors and engineers can face issues like failed inspections and legal liability. Moreover, as these rules are mandatory under federal law, the parties involved may face serious legal and financial consequences.