The Lunos e² decentralized high efficiency heat exchange whole house ventilation system remains a breakthrough in building technology - combining high performance with simplicity of installation and operation. Introduced in 2012 to the US market by 475, the system has proved its effectiveness and longevity.
Rather than installing a central heat exchange unit, requiring extensive ducting and construction intervention and coordination, one can install Lunos e² units through exterior walls - without ducting.
See an introduction video here:
The basic operating principles are straightforward:
- The units operate continuously (but can be turned off with a switch)
- The units are installed in pairs, working in a counter-flow manner: one supplies air while the other exhausts
- The flow directions and rates are synchronized for balanced ventilation, with 9-22 cfm flows reversing at approx. one minute intervals
- The system can simply provide airflow throughout the entire house/apartment
- The Lunos e² is part of a hybrid ventilation solution along with the Lunos eGO or separate intermittent bath exhaust on a timer or occupancy sensor
The units are small - practically the diameter of a compact disc. The basic components of the units include:
- Exterior grill with insect screen
- Plastic insulation element
- Highly efficient ceramic heat buffer
- Ventilator engine in sound muffling plastic chassis.
- MERV 5 or pollen filter
- Airflow optimized interior shield
The functioning concept is a pulsing, directed and balanced airflow that provides thorough mixing and exchange of interior air.
1) The 70 second cycles produce roughly a three foot pulse of fresh air to the space. In less than 10 minutes from starting, the fresh air has completely circulated within the space.
2) The pressure difference causes forced air direction from one side to the other.
3) And back in the opposite direction.
4) Providing intermediate mixing.
The farther you space the units apart, the better the mixing - although they can function properly as close as five feet from each other.
Important qualities of the Lunos e² units include:
- Quiet operation: 0.12 sones at the low (10 cfm) setting and 0.15 sones at the medium (15 cfm) setting. The units provide 42 decibel sound protection to outside.
- Dependable: The units are designed to exceed 100,000 hours of operation.
- Affordable: Small homes and apartments can be ventilated more inexpensively than central systems of similar efficiency and quality. This is true for new construction but particularly so in retrofit situations.
- Moisture Recovery: The Lunos e² heat transfer core also absorbs and releases approximately 20-30% of the moisture in the air stream - helping to moderate humidity levels in winter (but not enough to call them ERVs).
- Frost Free Operation: The Lunos e² requires no active frost protection. The units have been tested down to -32 °F and are successfully operating continuously through the winter in places like Norway, Estonia and Russia.
Efficient: Fans draw less than 1.4W each, with no stand-by/ghost power loads. The heat recovery is impressive with efficiency curve solidly in the 84-92% range (see diagram). Rated efficiency is 90.6% for the standard (12") e² units.
12 inch Lunos tube hidden in
thin wall using a drywall "column"
- All types of renovations. Standard size Lunos e² units require a minimum construction depth just under 12 inches. For thinner walls, either use standard Lunos e² fans with interior soffits (pictured at right), or Short (6.3") Lunos e2 fans (84% efficiency).
- Low energy and Passive House buildings. (See PHPP inputs for Lunos e2)
- Can be installed anywhere you can fit them!
- Low voltage (12V) DC power at fans.
- No tools needed for maintenance.
- No ductwork.
To find out more about the Lunos e², click through to the product page, where you'll find the spec sheet, installation instructions, video, and more under "Reference Downloads", "Videos", and "Related Blog Posts" sections of the page.