The Lunos e² Primer
The Lunos e² decentralized high efficiency heat exchange whole house ventilation system is a breakthrough in building technology - combining high performance with simplicity of installation and operation.
Rather than installing a central heat exchange unit, requiring extensive ducting and construction intervention and coordination, one can now 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 10-24 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.
- 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.
- The pressure difference causes forced air direction from one side to the other.
- And back in the opposite direction.
- 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.
- Flexible: The Lunos e² is suitable for a variety of applications
New construction of single and multi-family buildings.
- 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.