My concern is one of liability.
Even with sealed combustion devices the manufacturers (for example) of gas fireplaces have in the "fine print" warnings for potential back drafting with CYA clauses and advisement for MUA...no one…"
Welcome to Home Energy Pros Forum. Feel free to join the conversation in the Forum and Groups. And share your energy efficiency photos, videos, and upcoming events. If you're blogging about home performance, this is the place…"
Today there is no research that I can find to support less than 500 fpm.
As I noted above we have much high velocity systems without noise issue due to locating the fan away from the hood, minimizing fittings and using silencers.
What I am…"
All good comments and questions that need to be explored for residential systems.
We have large residential system (1200 cfm) designed for 800 to 1000 fpm with single inline fan located 30 to 40 feet away from the range hood...two silencers…"
"Seems like high velocity and low noise are at odds with each other. And one of the biggest impediments to people using range hoods in their homes is noise. Wouldn't requiring higher velocity exacerbate this problem? Sorry forgive my ignorance…"
Good questions. I will defer to HVAC & grease experts on this.
Is the main safety issue grease fires in the exhaust duct & hood? If so, do residential hoods & stoves get hot enough to be a problem, or is it just for…"
"Below is a copy/paste from a side bar with Rick Karg...joining as soon as he gets approved...
Rick KargRobert, regarding your low velocity consequences posting: I don't think the velocity is an issue. Velocity is primarily limited because of…"
"Interestingly the 500 fpm was a drastic reduction from a previous requirement of 1500 fpm established by NFPA following an ASHRAE research project which looked at the impact of velocity on grease deposits ...100 cfm in an 8" duct is less than…"
"I'm not familiar with any recommended minimum velocity for residential range hood exhaust ductwork. I suspect that long-term grease deposition in the ducts is minimal for most residential applications, given the intermittent use of the cooktop…"
Has anyone looked at the low velocity consequences as a result of marrying these statements pulled from the resource documents…“Use 8-inch round smooth metal ducts” and “ASHRAE and other groups recommend a minimum of 100 cfm.” and “HVI recommends 100-250 cfm airflow rate”?Just saying if authoritative voices are offering up resources there is a need to address minimum recommended velocities and cross check recommended duct sizes with recommended air flow rates.Not sure if the residential…See More
Welcome to Home Energy Pros Forum. Feel free to join the conversation in the Forum and Groups. And share your energy efficiency photos, videos, and upcoming events. If you're blogging about home performance, this is the place for you!