Inspectorjoe Posted July 13, 2011 Report Share Posted July 13, 2011 Yesterday I had a good-size 1986 Tudor. During my initial tour of the property I noticed both heat pump outside units were manufactured July 2007 and the basement indoor unit was a month older. I shouldn't have much to do as far as HVAC I thought. One thing was strange though - the airflow at all of the registers on the second floor was very anemic and not very cool. It was 90 degrees and sunny. When I finally got up into the attic nearly 5 hours into the inspection, my breath was taken away - not by the heat, but by this train wreck of a duct system. What on Earth were they thinking? Click to Enlarge 60.92 KB Click to Enlarge 57.81 KB Click to Enlarge 51.34 KB Click to Enlarge 50.66 KB Outside air temp was 90. I didn't check the attic temp, but it wasn't too comfy. After running full-tilt for nearly 5 hours, the system couldn't get the second floor lower than 85 degrees. At the plenums, the return temp was 87.1 and supply temp 60.7. Just had to share. Quote Link to comment Share on other sites More sharing options...
Erby Posted July 13, 2011 Report Share Posted July 13, 2011 Will such wonders never cease? - Quote Link to comment Share on other sites More sharing options...
Marc Posted July 13, 2011 Report Share Posted July 13, 2011 A common test I used in hot weather is to turn the thermostat down to about 60 or less to make sure it doesn't cycle off. I then set my thermometer on the kitchen CT or elsewhere and let her run for the duration of the inspection. Fairly often I'll get a zero drop in temperature after 2 - 3 hrs of continuous operation with the indoor temp in the high 70's. When I get that, I write it up very simply: HVAC system is not functioning as intended. Who could argue with me? It ain't a heat wave. AC is supposed to cool the house and it isn't. Marc Quote Link to comment Share on other sites More sharing options...
Jim Katen Posted July 13, 2011 Report Share Posted July 13, 2011 A common test I used in hot weather is to turn the thermostat down to about 60 or less to make sure it doesn't cycle off. I then set my thermometer on the kitchen CT or elsewhere and let her run for the duration of the inspection. Fairly often I'll get a zero drop in temperature after 2 - 3 hrs of continuous operation with the indoor temp in the high 70's. When I get that, I write it up very simply: HVAC system is not functioning as intended. Who could argue with me? It ain't a heat wave. AC is supposed to cool the house and it isn't. Marc If the house is vacant or if the AC hasn't been run, and if it's very humid, it might take longer than 2-3 hours. The AC has to remove the humidity before it can produce any meaningful cooling. Quote Link to comment Share on other sites More sharing options...
Neal Lewis Posted July 13, 2011 Report Share Posted July 13, 2011 A common test I used in hot weather is to turn the thermostat down to about 60 or less to make sure it doesn't cycle off. I then set my thermometer on the kitchen CT or elsewhere and let her run for the duration of the inspection. Fairly often I'll get a zero drop in temperature after 2 - 3 hrs of continuous operation with the indoor temp in the high 70's. When I get that, I write it up very simply: HVAC system is not functioning as intended. Who could argue with me? It ain't a heat wave. AC is supposed to cool the house and it isn't. Marc Wouldn't it be better to check the room temperature on the thermostat, rather than at the kitchen counter? Provided the thermostat is properly located? Quote Link to comment Share on other sites More sharing options...
Marc Posted July 13, 2011 Report Share Posted July 13, 2011 Jim's right. I'd use some other method to get a feel for the performance of the AC system if the house were vacant. Neal, it doesn't matter much to me where I check the temperature. I try to use common areas such as kitchen, living or dining rooms. Each should experience a drop in temperature if the AC runs non-stop for 2 or 3 hours. Marc Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted July 13, 2011 Report Share Posted July 13, 2011 Could be something simple too like a dirty filter, dampers being closed... I don't think you can make a call whether the a/c is working properly just by seeing if the room temperature drops - too many variables. In Joe's post the a/c could have been working great but the air distribution system is crap. Quote Link to comment Share on other sites More sharing options...
Marc Posted July 13, 2011 Report Share Posted July 13, 2011 Could be something simple too like a dirty filter, dampers being closed... I don't think you can make a call whether the a/c is working properly just by seeing if the room temperature drops - too many variables. In Joe's post the a/c could have been working great but the air distribution system is crap. Hello Terry, I define HVAC system as including the ducts. As an inspector I don't care much for determining whether an AC issue is with the ducts, air handler/furnace or condenser unit or all of the above, though I do check many particulars such as filters, coils, ducts, etc. I guess what I'm saying here is that I often see the whole system in such a big mess that I just write it up once and make my recommendation for review/repair by a contractor. The test that I do gives me foundation that few can argue with. This is what I would have likely done with Joe's OP. BTW, my Fluke 971 measures humidity as well as temps, which I may also chk if temps haven't dropped. Marc Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted July 13, 2011 Report Share Posted July 13, 2011 How do you like the Fluke Marc? Quote Link to comment Share on other sites More sharing options...
Marc Posted July 13, 2011 Report Share Posted July 13, 2011 How do you like the Fluke Marc? I don't. The humidity readout on the 971 takes a long time to acclimatize and the temperature readout drifts over a wide range. Would you like it? I'll have to find something else first. Marc Quote Link to comment Share on other sites More sharing options...
Terence McCann Posted July 13, 2011 Report Share Posted July 13, 2011 No but thanks. I'm always interested in new gadgets - some work better than others though (like my bore-a-scope... POS). Quote Link to comment Share on other sites More sharing options...
ericwlewis Posted July 16, 2011 Report Share Posted July 16, 2011 Yesterday I had a good-size 1986 Tudor. During my initial tour of the property I noticed both heat pump outside units were manufactured July 2007 and the basement indoor unit was a month older. I shouldn't have much to do as far as HVAC I thought. One thing was strange though - the airflow at all of the registers on the second floor was very anemic and not very cool. It was 90 degrees and sunny. When I finally got up into the attic nearly 5 hours into the inspection, my breath was taken away - not by the heat, but by this train wreck of a duct system. What on Earth were they thinking? Click to Enlarge 60.92 KB Click to Enlarge 57.81 KB Click to Enlarge 51.34 KB Click to Enlarge 50.66 KB Outside air temp was 90. I didn't check the attic temp, but it wasn't too comfy. After running full-tilt for nearly 5 hours, the system couldn't get the second floor lower than 85 degrees. At the plenums, the return temp was 87.1 and supply temp 60.7. Just had to share. "the boss says as soon as we use all this duct, we can go home" Quote Link to comment Share on other sites More sharing options...
Inspectorjoe Posted July 16, 2011 Author Report Share Posted July 16, 2011 "the boss says as soon as we use all this duct, we can go home" Or ............... they charged by the foot. Quote Link to comment Share on other sites More sharing options...
plummen Posted August 25, 2011 Report Share Posted August 25, 2011 They were having problems with snow buildup on the roofs before the install! [:-monkeyd In all the years I spent in the building trades installers never ceased to amaze me,no matter what trade they were in! [:-taped] Im just glad to be retired! [:-party] Quote Link to comment Share on other sites More sharing options...
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