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slowmover · 06-17-2010, 11:11 PM

Another note My A/C guy said that my ducts are undersized (volume/ time) for 4 tons of air; *just* large enough for 3 tons of air. Not sure if that affects de-humidification; but it was definitely affecting the load on the old blower motor (drew just under 1000 watts). I want to test the new blower motor draw when I get a chance.

Of course the funny thing is the guy who commented about the duct size; was the guy who designed + installed the ducts in the first place.

You hit on it right there. Most contractors are only "okay" in the sense that they have to work with existing ductwork . . and my money and reading says that this is where the real problems/solutions lay. Even brand-new houses, supposedly energy-efficient (more than band-aid work) seem to not be as good as they could be. The explanations I've read mean to me that to build from scratch down here in pretty-much-needs A/C year-round-land that one might as well start enquiring about certified engineers and be willing to pony up the cost.

No matter the system type, you gotta deliver and retrieve. And much of it appears to be in the ducting. Computational-hydrodynamical-National Security-Agency-teraflop-number-crunching applies . . yeah, okay, an exaggeration. Much is known and formulated. But even more is lost in translation from scientists to engineers to contractors to homeowners.

Most of us are just not going to rip out the walls/attic/basement and re-configure room layouts for "the perfect system". Much as we'd like to. (Worst part about most post-war houses down South is the lack of basements to run ducting . . that, naturally, is better in 160F attics. With loss rates of 30% common after five years. Or, higher. On "energy efficient" designs).

I haven't read up on this in a few years, but I have owned five houses the past six years so have had time to install, repair, maintain central HVAC of differing ages and quality; on my own and with pro's. The ducting leaks are a huge, straightforward thing to fix. A genuine PITA. Worth a third of the A/C bill every month to get right.

Aeroseal Air Duct Sealing - w/o air duct cleaning, mastic, air duct dust

is an interesting service/product to look at.

06-17-2010, 11:11 PM	#17 (permalink)
slowmover Banned Join Date: Oct 2009 Location: Fort Worth, Texas Posts: 2,442 2004 CTD - '04 DODGE RAM 2500 SLT Team Cummins 90 day: 19.36 mpg (US) Thanks: 1,422 Thanked 737 Times in 557 Posts	Another note My A/C guy said that my ducts are undersized (volume/ time) for 4 tons of air; just large enough for 3 tons of air. Not sure if that affects de-humidification; but it was definitely affecting the load on the old blower motor (drew just under 1000 watts). I want to test the new blower motor draw when I get a chance. Of course the funny thing is the guy who commented about the duct size; was the guy who designed + installed the ducts in the first place. You hit on it right there. Most contractors are only "okay" in the sense that they have to work with existing ductwork . . and my money and reading says that this is where the real problems/solutions lay. Even brand-new houses, supposedly energy-efficient (more than band-aid work) seem to not be as good as they could be. The explanations I've read mean to me that to build from scratch down here in pretty-much-needs A/C year-round-land that one might as well start enquiring about certified engineers and be willing to pony up the cost. No matter the system type, you gotta deliver and retrieve. And much of it appears to be in the ducting. Computational-hydrodynamical-National Security-Agency-teraflop-number-crunching applies . . yeah, okay, an exaggeration. Much is known and formulated. But even more is lost in translation from scientists to engineers to contractors to homeowners. Most of us are just not going to rip out the walls/attic/basement and re-configure room layouts for "the perfect system". Much as we'd like to. (Worst part about most post-war houses down South is the lack of basements to run ducting . . that, naturally, is better in 160F attics. With loss rates of 30% common after five years. Or, higher. On "energy efficient" designs). I haven't read up on this in a few years, but I have owned five houses the past six years so have had time to install, repair, maintain central HVAC of differing ages and quality; on my own and with pro's. The ducting leaks are a huge, straightforward thing to fix. A genuine PITA. Worth a third of the A/C bill every month to get right. Aeroseal Air Duct Sealing - w/o air duct cleaning, mastic, air duct dust is an interesting service/product to look at.