Energy Efficiency Ratings for HRV sometimes not shown

[photoengineer]

For those who have more experience than my in the HVAC world:

When I do building inspections,I sometimes see EER or SEER energy efficiency ratings on rooftop Heat Recovery Ventilators or RTU's. Othertimes, I don't. Same with the plans. Sometimes they are listed and sometimes they aren't.

The recent building I did was a school, and there were EER ratings for all of the rooftop equipment except for the HRV's that served the restrooms. These were plate heat exchanger HRVs. The other HRVs all had energy efficiency ratings.

Any ideas as to why?

 

[DRWeig]

I am out today and can't pull up my 90.1 energy code from here, but I do not think there is a requirement in it for minimum SEER of HRVs. In other words, marking or marketing with that rating is not required to comply with the energy code.

Somebody else may have a better memory than I, so don't take my answer as definitive. I could (and frequently am) wrong.

Best to you,

Goober Dave

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[willard3]

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[DrRTU]

IECC 2012 / 90.1 – 2010 does not have minimum efficiency tables as with other equipment but does have a statement in C403.2.6 Energy Recovery Ventilation Systems. When you get forced into an ERV, then the system shall be 50% of the delta enthalpies at design. Performance will vary with flow rate. Manufactures have all different ratings but have used HVI, AHRI, AMCA and others to certify their designs. They may not be required to name plate the performance.

 

[DRWeig]

DrRTU - you make good points and answered the question, thank you for looking that up. You verified that there is no table of requirements in the 90.1 code.

However, I think you missed the terms EER and SEER in the original post. Delta enthalpy is the effectiveness, EER is the efficiency. EER and SEER are related to the heat recovered by the ventilator divided by the electric energy input for the driving motor, auxiiaries, and controls.

Thus, no standard requirement = no need to mark it on the unit or spec sheet. If you see them marked anyway, the purpose is for marketing.



Best to you,

Goober Dave

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[EnergyProfessional]

It sounds like you are a code inspector since you say you are doing inspections? If so, you can request the contractor/owner provide that information from the manufacturer.
alternatively if you can decipher manufacturer and model# you can get that information from the manufacturer. Keep in mind for ERV efficiency depends on flowrate.

 

[joehvac]

From what I have seen you are likely to find a % effectiveness. SEER and EER are used for rating cooling equipment with a compressor in it, such as rooftop units and chillers. ERV/HRV do not have a compressor and that along with the lack of minimum energy efficiency standards is why you don't see EER/SEER of them.

Best of luck.