I've had this problem with at a residential but I quit didn't under stand why I seen there wasn't any ventilation system in the Attic so I put a fan in the Attic thought what was gonna help I still had enough amount of sweat coming in the rest room.... I reinstalled the duct system just the rest it was really a work of art how they put that together it was an add on some it made a little sense what you just explain here , thanks a plethora
I was wondering when he said he’s never seen duct in a foam attic sweat because there has been a dehumidifier up there or if there was supply and return from the hvac to control the humidity because I’ve seen pretty high %RH in foam attic
Specific humidity is different from relative humidity, specific is the amount of grains, relative is exactly what it state relative as to what It could hold at that same temperature. Latent load 4.45 delta h x cfm =the latent load on the psyc chart.
@@TimothyNaugher perhaps, I’ve done it a couple times (before CCS). I like how Julian preps the ducts - we did it in retrofit situations, which is challenging... So far at CCS we’ve only installed one duct system outside the thermal boundary. Maybe next one of those we get I’ll try it again. * I’m interested to see what his duct leakage numbers are.
Neil Comparetto yea we only stayed at that hotel one night before the event but yea I’m looking forward to spending more time chatting with you next year
Damn ridge vents no good in a hurricane either. What about metal ducts in an attic, i presume they would take on more heat therefore would need even more insulation than flex duct under the same conditions?
Two new vertical air handlers were installed in ground floor commercial bldg unit. Air handlers are in closet, next to a room in conditioned space. The door between room and closet is not sealed, and it has a vents built into the door. Vent "fins" are stationary and angled down on the adjacent room side. The installers cut into the cold air sheet duct above each Air Handler and added louvered vents. Now the closet with the air handlers is a conditioned space and ducts are sweating and dripping. Seems to me this is not a correct installation.
I think the presenter misspoke - the MINIMUM attic ventilation is a total of 1 SF of vent/300 SF of attic space, not 300 SF/100SF of attic space ... this is the "300 Rule" - however, in hot climates most recommend 1 SF of vent/150 SF of attic space (called the "150 Rule" - I'm assuming Naples, FL is this sort of area.
what about duct sweating in a ceiling between the basement and main level floor? centrally located area of the ceiling, the duct is sweating and dripping through the sheet rock. customer has opened the ceiling and it is soaked. Unit is a 4 ton Bryant evolution extreme, over cool up to 3 degrees with humidity setpoint at 46% was enabled, setpoint in the house is 71 and comfort Is maintained, except the sweating ducts. Customer says the run times seem normal/ long enough.
Possible the unit is running longer than the old unit because this one is variable speed so now the ducts get much less drying time. Also it is colder in the basement ceiling vs other places in the house. Overcooling to dehumidify will help the house but make duct condensation worse. A separate dehumidifier would help.
Mr. Simms, great presentation. Are you available for hire to evaluate a situation in a beach house in Delaware? I am the architect. We have sweating ceiling in a lower level first floor situation. The ducts in in the ceiling space between the lower level and the floor above. No attic condition. But we have a problem and a mystery...
Td = T - ((100 - RH)/5.) where Td is dew point temperature (in degrees Celsius), T is observed temperature (in degrees Celsius), and RH is relative humidity (in percent). Apparently this relationship is fairly accurate for relative humidity values above 50%.
300SF Total ventilation per 100SF of floor space is ridiculous. That's 3 times the ventilation as floor space. Check your calculation again. That would require More ventilation that SF of my house. You corrected that later to 1SF/300SF. Just a little confusing...
Wow, what a plethora of information. Great video. Thank you
13:00 start here
13:30 Jason Julian
35:00 mastic is thermally conductive, not insulative
I've had this problem with at a residential but I quit didn't under stand why I seen there wasn't any ventilation system in the Attic so I put a fan in the Attic thought what was gonna help I still had enough amount of sweat coming in the rest room.... I reinstalled the duct system just the rest it was really a work of art how they put that together it was an add on some it made a little sense what you just explain here , thanks a plethora
I’ve meet Rick sims at my tech school in Naples years back, smart guy
49:30 “Spontaneous fabrication.”
😅 ha! Lol, nice one!
Been to a couple of his classes in Naples. Endless information, always make learning fun!!!
Great content!! Appreciate all the education videos.
This was a awesome video and well explained!!! I learned a lot from Mr. Sims
I was wondering when he said he’s never seen duct in a foam attic sweat because there has been a dehumidifier up there or if there was supply and return from the hvac to control the humidity because I’ve seen pretty high %RH in foam attic
Specific humidity is different from relative humidity, specific is the amount of grains, relative is exactly what it state relative as to what It could hold at that same temperature. Latent load 4.45 delta h x cfm =the latent load on the psyc chart.
I’ve watched it three time already lol.
You going to try to foam some ducts?
This was a great lecture for sure. I wish I got to hang out with you more Neil!
@@joeshearer1247 same! Hopefully next year.
@@TimothyNaugher perhaps, I’ve done it a couple times (before CCS). I like how Julian preps the ducts - we did it in retrofit situations, which is challenging... So far at CCS we’ve only installed one duct system outside the thermal boundary. Maybe next one of those we get I’ll try it again. * I’m interested to see what his duct leakage numbers are.
Neil Comparetto yea we only stayed at that hotel one night before the event but yea I’m looking forward to spending more time chatting with you next year
Damn ridge vents no good in a hurricane either. What about metal ducts in an attic, i presume they would take on more heat therefore would need even more insulation than flex duct under the same conditions?
Two new vertical air handlers were installed in ground floor commercial bldg unit. Air handlers are in closet, next to a room in conditioned space. The door between room and closet is not sealed, and it has a vents built into the door. Vent "fins" are stationary and angled down on the adjacent room side. The installers cut into the cold air sheet duct above each Air Handler and added louvered vents. Now the closet with the air handlers is a conditioned space and ducts are sweating and dripping. Seems to me this is not a correct installation.
I think the presenter misspoke - the MINIMUM attic ventilation is a total of 1 SF of vent/300 SF of attic space, not 300 SF/100SF of attic space ... this is the "300 Rule" - however, in hot climates most recommend 1 SF of vent/150 SF of attic space (called the "150 Rule" - I'm assuming Naples, FL is this sort of area.
Does anyone know where you would get the Inner Film R-Value and Outer Film R-Value in the equation (at the 14:23 mark)? Thanks.
Thanks that helped a lot
Texas has nothing but hot attics and every duct system is installed there. 120 degrees is the norm in the attics. They don't sweet much.
Can you make the flexible ducts "dirty".
@@mrapma not sure what you mean by dirty.
what about duct sweating in a ceiling between the basement and main level floor? centrally located area of the ceiling, the duct is sweating and dripping through the sheet rock. customer has opened the ceiling and it is soaked. Unit is a 4 ton Bryant evolution extreme, over cool up to 3 degrees with humidity setpoint at 46% was enabled, setpoint in the house is 71 and comfort Is maintained, except the sweating ducts. Customer says the run times seem normal/ long enough.
Possible the unit is running longer than the old unit because this one is variable speed so now the ducts get much less drying time. Also it is colder in the basement ceiling vs other places in the house. Overcooling to dehumidify will help the house but make duct condensation worse. A separate dehumidifier would help.
Do you guys have anything on duct temperature gain? Max acceptable ... anything code related, etc.
Mr. Simms, great presentation. Are you available for hire to evaluate a situation in a beach house in Delaware? I am the architect. We have sweating ceiling in a lower level first floor situation. The ducts in in the ceiling space between the lower level and the floor above. No attic condition. But we have a problem and a mystery...
what's the blower door test score for the home look like?
Is the dewpoint the same as the ambient air temp.
Td = T - ((100 - RH)/5.) where Td is dew point temperature (in degrees Celsius), T is observed temperature (in degrees Celsius), and RH is relative humidity (in percent). Apparently this relationship is fairly accurate for relative humidity values above 50%.
No - only if it’s raining (usually) because dew point is the temperature where the moisture starts condense
300SF Total ventilation per 100SF of floor space is ridiculous. That's 3 times the ventilation as floor space. Check your calculation again. That would require More ventilation that SF of my house. You corrected that later to 1SF/300SF. Just a little confusing...
The teacher snores while talking. Kinda distracting lol.
UA-cam auto play needs to stop with battery wasting practices