I am looking for feedback on a new residential air airflow balancing product scheduled to be released in 2019.

A negative feedback is as much appreciated as a positive one.

Here is the link:

Thank you.

Antoine karam.

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Hi Antoine, see this article at Energy Vanguard, especially my comments:

I can't tell much from the page you linked but I think the concerns addressed in my comments would apply to the Cello product if the intended market is consumers (as opposed to the trade).

A duct system MUST be designed to accommodate variable air volume in order to maintain adequate airflow through the coil (applies to heat pumps and air conditioners). Furnaces and hydronic forced-air systems are a bit more tolerant of airflow across the heat exchanger but closing off registers risks overheating the heat exchanger (HX), which can trigger high-heat limit switches and lead to premature failure.

Even if the sensors referenced on the page are designed to insure proper HX flow rates, they must be professionally installed and commissioned. In existing homes, this nearly always requires modifications to the duct system to make it work correctly. 

Bottom line: a variable air volume system can never be considered a consumer grade product. Air balance and system flow are among the more challenging aspects of residential HVAC, and in my experience, professionally designed and installed zoned systems are more often than not implemented poorly. Attempting to market automatic dampers to consumers ignores this reality.

Great feedback. Thanks David.

The intended market is residential homes. However, the installation will be handled by professional HVAC techs. we are implementing a B2B model for this product.

Installing Cello is the last step. First, the HVAC tech will need to ensure the furnace/blower/filter/duct system are operating properly before installing Cello. 

Cello is only needed if access to the duct inline dampers is not feasible without tearing down walls and/or the ceiling.

in layman's terms, Cello is automating the airflow balancing exercise done by a tech. The balancing process is continuously being updated on a daily basis. The business model will ensure the tech makes money on a recurring basis in addition to the initial setup.



Despite references to the term 'air balance', I was thinking Cello would be used by occupants to set rooms to different temperatures, in particular, to shut off rooms that are not in use. That's where you get into trouble, as that isn't air balancing but variable air volume. Are you saying that would not be supported?

If we can give an incentive to the pros (re: recurring revenue) to ensure their systems maintain proper air balance (with the emphasis on 'proper'), that would certainly be a valuable contribution to the industry. But I remain skeptical that such a system is possible, or that homeowners would pay a recurring fee for something that should be done correctly to begin with.

To make that work, the tech would have to do a proper room-by-room load calc (in order to know what that correct balance actually is), and the flows to each room would have to be measured. Having worked in R&D for a company that developed highly accurate flow hoods, I don't see how you can do that with in-duct sensors. This probably isn't the best place to have that discussion, as I imagine it involves proprietary technology.

we are not supporting room by room temp control. That's called zoning.

Northern climate homes with both heating and cooling, do need airflow adjustments on a seasonal basis.

Even newly built homes have airflow balancing issues. at least that's the Canadian experience.

airflow balancing is achieved via intelligent algorithms (proprietary technology) running on the cloud side. The cello dampers use WiFi for cloud communications. No gateway required.

again thanks for your valuable feedback.


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