My mother's orchids have always looked terrific, but now the ones that are left look really sad. She thinks that maybe it's due to the air filter near them. This is not an ionizing filter but just a hepa filter. The orchids are also over an air vent, but that's been there for 20+ years, and it never seemed to bother them. I was thinking maybe the problem with them is something entirely different. Just wondered if anyone has any ideas what might be harming this orchid and making it look like this.

Thanks so much for any help!

Welcome to the site!

Moving your question to the Orchids Forum.

they don't look too bad, newba. In wintertime being on vent might dry them out. If they've been in same pot a long time might need to refresh potting medium some bark and sphagnum moss.
Orchids are tougher than folks think.

See one of my Phalaenopsis which has received the (passive-aggressive) attentions of my cat. Its OK tho.

The flowers wilting is just their natural progression, they are finished blooming. The yellow leaf tip may be a nutrient deficiency, so a spray of water with a little soluble fert in it may be in order after recent growth during the summer. Yes, orchids even indoors do grow more in the summer because the house will be warmer, and the light is stronger from the windows.

I'd say definitely move the hepa filter so it's not blowing on the orchids. That seems to be the only change they've seen. Orchids are epiphytes that do gather nutrients from the air, so cleaning the air, and blowing dust-free air on the orchids constantly would not do them any good. They like air movement, but not a constant draft.