This week’s question:
A HERS rater’s quest to understand how to model the Lunos e2 and eGO units in REM/rate software.
“Hi, I’m a HERS Rater and need to model Lunos e2 and eGo units in REM/rate software for a HERS Rating. Can you tell me what values should be used for the sensible recovery efficiency % and total recovery efficiency % inputs? I understand these units are not yet listed on HVI, so I can’t use that data. Thanks.”
…here’s our response:
Very good question. While the unit is not HVI certified, it does have the German certification (DiBT), and we can recommend that these published values be used. The German DiBT tested efficiency of 90.6% average can be used as ASE in REM/Rate. The DiBT is part of the federal government of Germany and a fully independent 3rd party regulatory organization.
If you are running the fans on high (or modeled them as such) at 20CFM, the efficiency is rated at 85% by DiBT. The system is designed to draw around 10W at that speed – but this depends on the pressure it is counter-acting. And even more efficient at the low flow setting, using just 4W.
…and here’s another HERS rater’s perspective:
“I’m tending to be conservative and use the design temperature end of the temp/efficiency curve I received in German and give it an 80%, with power consumption as stated in the literature. (…..) I did check with my HERS QA Designee, and there is no formal process for doing this other than resorting to manufacturer’s data sheets and properly applying good judgement and being conservative.”
So, HERS raters, there you have it. Some unique insight on how to model the Lunos system in your REM/rate software – you can use the values verfied by independent testing as done by a Federal German agency or use a more conservative values to size your systems with more room for error.
The third party tested very impressive efficiency have been shown in real life application in the USA for over 4 years now and proven it’s value in terms of energy consumption and heat recovery. Lunos fans are a high-quality, flexible, eloquent and effective solution, providing fresh clean air and a healthier indoor environment for your next project. Purchase them here or watch our video intro to the Lunos heat recovery system.
Already used the Lunos and looking for what’s next? Stay tuned for the appropriately-named Nexxt from Lunos, a semi-central HRV requiring only one exterior wall penetration, but providing the ability to duct to additional fans, or call us to ask about the Lunotherm, an exterior insulation system to direct the flow of air out a window opening instead of through an exterior grill.