Slow cooling

[Bptx21]

I’ve had my Google nest for a little over a month now and it would cool my house great within 2 ish hours from 77 degrees to 68 degrees.  Starting 2 nights ago it started taking the entire night 8pm-6am to cool the house.  Any idea what would be causing this all of a sudden?

[CoolingWizard]

@Bptx21 , then s could be caused by poor airflow.  If the air filter is dirty, or the coil is dirty the cooling capacity is compromised.  If the outdoor coil is dirty again your system performance  will be compromised.  

AC Cooling Wizard

[Markjosephp]

Hi everyone,

Thank you for taking the time to let us know about your inquiry.

Thanks for the input, @CoolingWizard.

@Bptx21, in addition to what was shared above, another factor for inefficient cooling might be power-related issues. Were there any instances where your AC turned off unexpectedly and then turned back on as it was trying to generate cool again? Also, what type of Nest Thermostat is this?

Regards,
Mark

[Dan_A]

Hey there,

I wanted to follow up and see if you still needed help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Best,

Dan

[Brionabrooks]

Hi! I am having a similar issue. I just had my AC unit serviced because it froze over. The filter was cleaned and the air seemed to be working, but now it says 2+ hours to go from 78 to 71 and has been in this mode all day. Please advise. 

[CoolingWizard]

@Bptx21 , If an AC system is frozen over, there can be a number of causes.  First poor airflow over the evaporator coil; dirty filter, or dirty coil.  Second, low on refrigerant charge; possible system leak or not properly charged when serviced.  Third, defective TXV/metering device.  The Nest has to be operational for a few weeks during the peak days of summer or winter to become more accurate on its estimation. It uses the local weather data and the past performance of your HVAC system to make calculations. If the thermostat is not detecting the your system is cooling efficiently, it will keep extending the time.  If you had your system serviced, what did they quote to you for the Superheat or Subcooling of your system? What if any repair or services did they perform?

AC Cooling Wizard

AC Cooling Wizard

[Brionabrooks]

This is super helpful! The filter was replaced, coolant levels replenished and the unit was cleaned. I was told there is a coil leak that would be a more major repair and am thinking that may be the culprit now. I am having that repaired tomorrow and hoping that does the trick. 

[CoolingWizard]

Keep in mind, they will need to find the leak, recover the refrigerant, fix the leak, pressure test the system, if that passes, perform a deep vacuum, if that passes, then Recharge the system. And lastly, using superheat or subcooling fine tune the system.

Leaks in the system can sometime be spotted. There will be refrigerant oil around the area of the leak.  And if it has been leaking for some time, you will have dirt attracted to that oil.  

AC Cooling Wizard

[Dan_A]

Hi Brionabrooks,

It sounds like a plan. We'll be keeping this thread open for a few more days and waiting for an update from you.

@CoolingWizard, as usual, it's great to have you and your knowledge.

Cheers,

Dan

[Dan_A]

Hello there,

I'm checking back to ensure you've got the answer you're looking for. Feel free to let us know if you have more questions about this.

Kind regards,

Dan

[LovelyM]

Hey Brionabrooks, 

We want to ensure you are good to go. Please let us know if you are still having trouble, as we will be locking the thread in 24 hours due to inactivity.

Thanks, 
Lovely

[Brionabrooks]

Everything has been resolved, thanks so much. 

[LovelyM]

Hello again Brionabrooks, 

Thanks for keeping us in the loop and I'm glad everything is sorted out on your end now. I'll close this thread shortly, so if you have further concerns or questions, feel free to create a new post. 

Best,
Lovely