In this article I will briefly discuss the difference between HRV (Heat Recovery Ventilators) and ERV (Energy Recovery Ventilators), best installation practices, applications, operating features, balancing and warranty.
We have been excited to be spec’ing this product in our high-performance homes, Net Zero and Energy Star projects. This ERV, however, does not have a Passive House certification. It will work great in any project/property under 3000 square feet. It does only move about 100 CFM, which I find is a little small for houses with three bedrooms or more. It works very well when supplementing fresh air, when partnered with mini-splits or VRF Heat Pumps for fresh, balanced air with energy recovery which makes it a very affordable, cost-effective IAQ solution. The Intelli-Balance is HVI certified and Energy Star rated for the Canadian market only.
As some of you may remember the introduction of HRV/ERV’s in the Midwest 20 years ago resulted in a lot of frozen cores from our cold winters. It was so problematic that our industry almost quit installing them. Manufacturers scrambled with research and development to produce technology that allowed re-circulation to defrost these cores. HRVs and ERVs are similar devices in that both supply air to the home and exhaust stale air while recovering energy from the exhaust air in the process. The primary difference between the two is that an HRV transfers heat while an ERV transfers both heat and moisture. Specifically, it is the latent energy being transmitted through the ERV core. In layman’s terms: helps expel moisture during incidences of high relative humidity (RH) and helps return moisture back inside during the winter for a healthier, more comfortable living environment. You will find that ERV’s generally carry a cost difference of about 15% more than a standard HRV.
In our Minnesota applications (Northern Climates) the FV-10VEC1 is rated cold climate. This is accomplished by a motorized damper and timing sequence that diverts and recycles exhaust air through the ERV core to defrost. When the outdoor temperature is < -22°F (-30°C), the defrost cycle is initiated and the product will stop operating for 47 minutes, then operate in heat exchange mode for 4 minutes in order to sample the outdoor temperature. It then operates in circulation mode for 9 minutes in order to defrost (exhaust and supply air are 50 CFM). Defrost cycle overrides the ASHRAE 62.2 timing function.
I like that this ERV provides four port connections for connecting either 4 inch or 6 inch duct connections. We have utilized multiple applications of connecting into either existing furnace ductwork or point of use; pulling stale air directly from bathroom/kitchen and refreshing air back into bedrooms and common spaces. Panasonic also offers a concentric vent termination kit, allowing for only one penetration through the thermal envelope. Mounting the unit can be wall or ceiling mounted either vertical or horizontal depending on how tight your mechanical room is. Like many ERV’s/HRV’s the hinge on the door allows for complete removal so full clearance to swing the door open is not necessary.
The Intelli-Balance 100 features two ECM brushless motors with built-in SmartFlow™ technology. When the ERV senses static pressure, its speed is automatically increased to ensure optimal CFM output; regardless of a complicated or lengthy duct run. Both ECM motors are rated for continuous run. Both motors offer the unique ability to select your required supply (50-60-70-80-90-100 CFM) and corresponding exhaust airflow, with the simple turn of a dial. We like this as it allows for easy balancing with a dual port manometer. The mechanical code in MN requires ‘balanced’ airflow however adjustability of the fan speeds allow for either a slightly positive or negative house pressure.
The operational controls on the Intelli-Balance allow a furnace or air handler to initiate operation, or the unit can be operated with a switch or continuous operation utilizing the ASHRAE 62.6 standard. This covers whole house ventilation, requiring that continuous mechanical ventilation be 7.5 CFM per bedroom (master bedroom X 2) plus 1 CFM per 100 square feet, with sone not to exceed 1.0
In Summary with a 6 Year Warranty on the ECM motors and 3 Years on all other parts users should feel confident in its longevity and operation. I have always found that Panasonic is exceptional in its customer service and more importantly tech support. Not all ERV’s fit every application but I find the Panasonic to be user and installer friendly with a lot of neat features packed into a small unit.
Dustin Denison – Principal, Applied Energy Innovations
Dustin Denison is Principal of Applied Energy Innovations (AEI) and 25 year veteran in the HVAC mechanical trades- Commercial, Industrial and Residential. AEI provides services from Solar, Insulation, Construction and HVAC. Dustin holds 4 Masters: Warm air/Ventilation, Refrigeration, Boiler/Hydronics and Gas with over 30 professional licenses and certifications. With a specialty niche in high performance homes/buildings, Dustin has designed and installed systems with demanding performance expectations by utilizing cutting edge technologies, products and services in the HVAC field.