Mini Split Install and Service Tips
HVAC School - For Techs, By Techs
Bryan Orr
4.9 • 1K Ratings
🗓️ 3 January 2023
⏱️ 50 minutes
🧾️ Download transcript
Summary
Craig Migliaccio, aka AC Service Tech, returns to the podcast to share his knowledge about mini-split install & service. He also talks a bit about his upcoming book, "Inverter Mini-Split Operation and Service Procedures."
Mini-splits are unique because they are compartmentalized in ways that traditional central-air ducted systems are not. Mini-splits come in many varieties, including ducted and ductless types, as well as multi-zone types. Many are inverter-driven and have more electrical efficiency as a result and can vary their capacities based on load variation.
Mini-splits have metering devices at their outdoor units, and these devices may be electric expansion valves (EEVs) or capillary tubes. Inverter mini-splits also don't have filter driers because their PVE oil doesn't have the same acid concerns as POE oil, and they don't have traditional liquid lines.
Flare connections are also critical when installing ductless systems, especially because you want systems to be tight to prevent leaking and contamination. Craig likes eccentric flaring tools with offset cones, and he recommends using flare nuts from the equipment manufacturer, not the line set manufacturer. He covers other flaring best practices as well.
The charge is quite small in mini-splits, so weighing the charge and being careful and deliberate during charging is critical. Refrigerant leaks can also be highly problematic; corrosion and poor flare connections are common causes of leaks.
Craig and Bryan also discuss:
- Hyper-heat systems
- Coefficient of performance (COP) and BTU output
- Moving between PSC and ECM or inverter technologies
- Mini-splits vs. VRF/VRV technologies
- Pressure testing and leak detection
- Compressor diagnosis
- Thermistors and electrical resistance
- Heat sinks and mounting circuit boards
- Selecting a location to install a mini-split
- Things to consider when checking the charge
- Why measure superheat and subcooling?
- Cleaning and maintenance best practices
Check out Craig's YouTube channel at https://www.youtube.com/@acservicetech.
Starting January 1st, 2023, you can buy Craig's book on his website, which has a bunch of other good resources. Visit that site at https://www.acservicetech.com/.
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Transcript
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| 0:00.0 | The free education provided by HVAC school is made possible by our great sponsors. |
| 0:10.0 | Refrigeration Technologies at Refriger tech.com. |
| 0:12.9 | They make many, many great products. |
| 0:15.1 | John Pastarello originally started the company |
| 0:17.7 | when he invented Big Blue, which is hands down my favorite bubble type leak |
| 0:22.1 | detector. It's so much more than just soap bubbles. It is a leak reactant that's designed to show even tiny, tiny bubbles without creating any corrosion and without reacting to electronic leak detectors. |
| 0:35.0 | It's great stuff. |
| 0:35.8 | It comes in the spray bottle. |
| 0:37.8 | If you haven't tried it yet, |
| 0:38.7 | try out Big Blue from refrigeration technologies |
| 0:41.5 | and also check out their leak detection guide |
| 0:44.3 | that's on the Refrigeration Technologies website. Just browse around a little bit at |
| 0:47.6 | Refrigerateech.com. They have really great training and education materials there as well. |
| 0:52.8 | Refrigeration Technologies at refriggedec.com. |
| 0:56.5 | Carrier and carrier.com? |
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... |
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