3 ms·
Don't more modern AC units use VFDs that can run the compressor at arbitrary speeds, which is an improvement over both fixed 3 phase power and a starter capacit
by jrockway 3y ago
Don't more modern AC units use VFDs that can run the compressor at arbitrary speeds, which is an improvement over both fixed 3 phase power and a starter capacitor? Maybe this tech hasn't made it into the house-sized units yet, though.
- lfowles 3y agoIt was only present on the high end when we were replacing our system in 2021.
- lizknope 3y agoI just replaced one of my two HVAC units with a variable speed compressor. It cost a lot more than the single or 2 stage units but it is more comfortable, uses less electricity, and runs at "low" to dehumidify longer.
- kelnos 3y agoUnfortunately these more modern units are still stupid expensive (in the US) compared to the older style. Unclear why; probably some sort of shenanigans with the HVAC manufacturing companies.
- amluto 3y agoLittle variable-speed units sold as ductless minisplits are fairly inexpensive in the US. They’re especially reasonable if you actually use them in a ductless configuration, because you don’t have to install ducts. The fact that they might have a higher list price than a conventional single-speed outdoor unit and indoor evaporator coil is a red herring, as the conventional units can’t do anything on their own, and they need a furnace and a fan added to be useful.
- mindslight 3y agoVFDs / "inverters" are happier on 3 phase as well, because the input rectifier caps can be much smaller. Whereas with single phase they have to be large enough to store energy for riding out the zero crossings of low power delivery.
- deleted 3y ago[deleted]