Dry heat and runtime in Palm Springs
冷氣度日 2604、濕度只有 0%、一年 167 天超過 32°C——問題是運轉時數、日曬與灰塵，不是除濕; 屋齡中位 1977 年——那個年代的風管與絕緣多半跟不上現在的機組效率，換機前值得先看風管.
冷氣度日 2604、濕度只有 0%、一年 167 天超過 32°C——問題是運轉時數、日曬與灰塵，不是除濕
屋齡中位 1977 年——那個年代的風管與絕緣多半跟不上現在的機組效率，換機前值得先看風管
Palm Springs runs about 2604 cooling degree days a year, which is a direct proxy for how many hours the compressor will actually turn - and compressors wear out by running hours, not by calendar years.
Why this changes what you should buy
In a dry climate the machine is doing almost pure sensible cooling, so the limiting factors move outdoors: how hot the condenser gets, how much dust is packed into its fins, and how many hours a year it runs. Those are maintenance and placement questions more than equipment questions.
Palm Springs gets roughly 167 days a year above 32 Celsius, and those are the days a system that is even slightly undersized will never catch up.
What to ask for, in order
- A Manual J load calculation, not a square-footage rule of thumb
- Shade or at least afternoon relief for the outdoor unit, without blocking airflow
- A maintenance interval that includes washing the condenser coil, which fills fast here
- Duct inspection before sizing, because attic ducts in this climate leak into very hot air
The median home in Palm Springs dates from 1977, which is a good guide to what the ductwork looks like behind the walls.