We all need fresh air. But energy-efficient homes are built to be airtight. So — how can you get the fresh air you need while keeping your energy bills low? A heat recovery ventilator or an energy recovery ventilator (HRV/ERV) is critical. These have become vital components for efficient homes. Suppose you are renovating an older home, making it more efficient and airtight. In that case, you should consider the addition of an HRV or ERV.
Most HRV and ERV systems use ducts to bring the exhaust air to the central heat-exchange unit and send the fresh air back through the building. They also have separate vents to bring in fresh outside air and send out stale exhaust air. That’s a lot of ducts!
What if you don’t have room for all those ducts or don’t want them? There is a solution — the ductless heat recovery ventilator.
What Is A Ductless HRV or ERV?
It provides fresh air, recovers the heat to save energy, and doesn’t need ducts running to each and every room in the house.
Who Makes Ductless HRV and ERVs?
Several companies make products of this type including, Lunos, Fresh-r, Blauberg, and Cyclone. We will provide short rundowns on each one below.
Lunos
The Lunos e2™ HRV System is a decentralized HRV system that uses pairs of small HRV units in each room that needs ventilation. Each unit is mounted on an exterior wall with a single vent pipe to the outside, a fan, heat exchange core, and integrated control.
This decentralized HRV works on an ingenious principle. It has only one pipe to the outside, alternating between bringing in fresh air and sending stale air out through the tube. First, it brings in fresh air for a while, and then the fan switches direction and sends out the exhaust air. By switching direction periodically, each unit serves as an independent air supply and exhaust.
Inside the pipe, there is a heat exchange core made of a ceramic composite material. The exhaust air exchanges energy with the core, warming, or cooling it. When the ventilator reverses, it brings the fresh air through the same ceramic core, which transfers the heat energy it collected on the previous exhaust cycle. This cycle recovers 80 to 90% of the heat energy in the air, saving you on your energy bills. And it’s quiet and discreet, with only a small, sleek, unobtrusive grill on the wall. Though this unit is an HRV, it also manages moisture, so it acts similarly to an ERV.
Fresh-r
Fresh-r®, by Vaventis, makes several products.
The Fresh-r In-the-Wall is based on a single unit mounted on an exterior wall in a main room, with two pipes through the wall. It exchanges the heat between the exhaust air and the fresh air with a highly efficient copper heat exchanger.
It only operates when needed, based on carbon dioxide sensors, and does not use a system of ducts. So, the Fresh-r system has very low operating costs. The international Passive House Institute chose it as the overall lowest-cost heat recovery ventilator for high-performance houses. It is ideal for retrofitting older homes that have been made airtight because it is so thin that it can fit in an exterior wall. The company says that it acts essentially like a window that can breathe.
The Fresh-r On-the-Wall works similarly to the above mentioned Fresh-r In-the-Wall but can be installed in any existing home that is not undergoing major construction. Homeowners can add pollen and fine particulate filters to this product.
The Fresh-r Forward looks similar to the Lumos, but it serves a different purpose. It moves air from room to room instead of from the exterior to the interior of a house. It continuously measures CO2 and humidity to keep each room at optimal levels. It can be wifi connected so that data is viewable from an online portal.
Vento Expert
Blauberg, out of Germany, makes a line of ductless HRVs called Vento Expert. Models offer different ventilation rates, from 30 to 50 cubic meters per hour. They can be wifi connected so that units in separate rooms can “communicate” for coordinated operation.
Cyclone
Cyclone makes a product called the SV130 ERV. It operates in a similar manner to the Lumos and the Vento Expert. It has a maximum ventilation rate of 29 CFM. This product does not have wifi connectivity or additional filtration options. The installed filter is equivalent to a MERV 6.
How Much Do Ductless HRVs and ERVs Cost?
Given the specialized nature of these products, prices and availability seem to range widely. The Vento and the Cyclone can be found for just under $1,000. The Lunos is available in the US for just over $1,000. You’ll find the Lunos between $1,400 to around $2,000, depending on which options you choose in Canada. Unfortunately, the Fresh-r line does not have a wide distribution in North America but sells for around 2,200 Euros overseas.
If your home needs ventilation, a ductless HRV could be an excellent choice for you, especially if you have limited space to install ducts. Apart from the energy savings they offer, ductless HRVs are designed to fit inconspicuously into your home, with their low profile and quiet operation. A great example of this is the container cottage that we featured previously on Rise. In a house made of containers, there was not much space for ducts in the rooms. The architect chose to go with ductless HRVs, and they love the results.
