Hacked Systems With Terrible Duct Design | HVAC
ฝัง
- เผยแพร่เมื่อ 11 ก.ย. 2024
- Found 2 homes today with units not able to keep up with the southern summer heat. Both of these tennants are struggling to stay comfortable, the property management company has got some big decisions to make
#hvac #bluecollar #airconditioner #servicetechnician #techlife #hvacmaintenance #hvacrepair #hvaclife #toptes #ductwork #hvacsystems
People needs to change their filter every 2-3 months as HVAC guy aaid he prefer fiberglass green filters i dont like them i prefer pleated filters at my previous house always got filters from furnacefilters 20x20x4 and always merv8. Love your video
🤣👌🏾🔥
In some cases like these where money is probably an issue, telling them a window until for the back room is cheaper and will keep them chill - like kitty cat.
Didn't seem like a issue to have the plumbing ran though 🤷🏾♂️
LSAT should be at around 107F( +20 CTOA), but your low SH and SC with low head pressure suggest oversized metering device, and airflow issues
I'm gonna double down and say airflow issues but it's still not able to cool the whole house because they made additions with no ductwork added. Those rooms are getting hot and staying hot
My analysis of the first call from 0:00 to 10:45 in the video is as follows:
The issue is very low airflow, not an overcharge of refrigerant. The details are below:
1) The pressures and temperatures recorded at 2:18 indicate that the subcooling at 14.7°F is acceptable, and the superheat is critically low at 2°F, which you acknowledge. These readings are consistent with an orifice or piston type metering device, not a TXV metering device. However, these readings are more likely caused by low airflow than by a refrigerant overcharge.
2) The extremely dirty return air drop box at 1:45 almost certainly suggests that the evaporator coil is also dirty, which would restrict airflow. (You omitted inspecting it or conducting static pressure testing to evaluate airflow. - NOT GOOD. The low delta T is most likely misleading.)
3) The 24"x12" filter is limiting airflow, providing only half of the 4 square feet area required by a standard 1-inch furnace filter for a 3-ton system. Unfortunately, the pleated filter type currently in use requires at least 6 square feet of area to ensure adequate airflow for this system.
4) Moreover, the return air duct displayed at 3:20 and 3:30 appears to be a flex duct and seems significantly undersized.
5) The straightness of the supply ducts at 3:02 and 3:33 suggest that they are sheet metal wrapped in foil-backed insulation, which was never properly sealed, allowing water vapor to reach the metal duct, condense, and moisten the insulation during cooling operations. This would reduce the insulation's R-value and lead to corrosion of the ductwork underneath.
6) The supply air plenum is too short for proper distribution into the branch ducts.
7) The floor above the crawl space lacks insulation, adding to the home's heat load.
Thanks for the extreme analysis 😅. I didn't bother checking the airflow because this system was incorrect from the jump. I'm my area, this unit is severely undersized for the home. As well there are parts of the home with no vents in them at all. So I could've spent a crap ton of time there, taking apart the evap coil under the home just to do all that, likely not be able to bill for it because the problem still wouldn't be resolved. The return being 12x24x1 is definitely an issue but it's even worse because the area in that wall cavity was smaller than that so the air was choking down before it even got to the flex. I knew static pressure was an issue by which the force of the air pulling on the filter. There was just a lot wrong with that system
@@AB_HVAC Thank you for the appreciation. Were I there, my recommendations would include:
1) Conducting a Manual J heat load calculation to ascertain the precise equipment size required.
2) If the current unit is appropriately sized for the home, I would perform static pressure assessments on the existing supply and return air duct systems as they are.
3) I would pump the system charge into the condenser, remove the evaporator coil, pressure wash the evaporator, reinstall the coil, and retest system operation and static pressures.
The estimated cost so far would be between $2000 and $2500.
4) I am convinced that the RA duct system needs correction.
5) It is likely that the supply duct system also requires redesign and correction.
6) The expense for this work should be about two-thirds the cost of installing a completely new basic system, which should also be quoted.
7) Regardless of the outcome, be ready to maintain a positive reputation. Don't try to be cheap.
Maybe I missed it, but was the evaporator coil clean?
For that Goodman system?
@@AB_HVAC The one with the bad ducting.
Ah yeah I didn't check the evap coil but it's a split gas Horizontal Right application where they didn't add any vents to the addition spaces and they have no trunk line
Just one of those jobs that is shit.
Super duper shit