HVAC tech came by last night.
1. We cannot pull the unit out of the sleeve b/c of a wall blocking it. See pic below. We need about 20". The wall might be a structural wall based on a GJ post from 2018.
https://www.garagejournal.com/forum/threads/4-x-4-studs-found-in-strange-wall.386608/
2. We poured 32 oz of water into the pan from above the fins on the top of the unit. No leakage anywhere. He said that's more water than the system would generate. Not sure what he meant by that.
3. We couldn't visually spot a drain line anywhere.
4. We got the evaporator coil exposed and it was quite dirty. We ran the A/C and moisture started to form on the fins. The tech swiped his hands on the fins and they were wet. He sprayed the evap coil with diluted cleaner from a pump sprayer.
5. I left the A/C running and told the tenants to contact me if they see a leak downstairs. No call in 24 hours. Fingers crossed.
6. After watching some Coil cleaning videos today I think the hot intake air is hitting the fins of the evaporator coils. Since the fins are dirty air cannot freely pass and instead of condensing inside where the drain pan is, it condenses on the fins. Some of that condensations drips onto the bottom shell of the PTAC unit. The bottom shell of the PTAC unit has some holes in it by design. Once there is enough water on the shell it flows to these holes and drips onto the hardwood floor. I can see the stain marks on the flooring.
If the fins were clean, adequate airflow would reach the evaporator coil and the condensate would drip down into the pan. This is all my theory, I don't really know for sure.
The illustrated pictures might explain this better than I have.
7. We cant really clean the drain pan or condenser coils b/c we cannot pull the unit out. Ideally he would remove the entire unit and power wash it offsite... (clean the pan, and condenser, drain hole, etc). But we cant remove it b/c theres a wall obstructing access.
8. I have to say he was an honest guy, said the unit was working fine even though its 40 years old.
Questions
- Is there anything else we can clean give our limited access?
- Can you guys recommend a good evap coil cleaner. I have 3 other PTAC units in this apartment I'd like to clean. And I'd like to clean the problem PTAC unit again. Ideally the 1-gallon size cleaner so I can use my pump sprayer. I'll have another pump sprayer with clean water to rinse it off.