I grow orchids in a greenhouse but started by growing them in the home just like most people do, and like most people a Phalaenopsis was the orchid I chose and killed! Got to learn right!? So we have probably got something in common straight away!.
This did become problematic as my interest and collection grew, It wasn't long before the orchid bug really caught a hold and I longed to have a greenhouse, a place set up and specific for the culture of orchids.
There are differences between the two and I find it easier to grow in a greenhouse, for a start you can be more care free when watering. Growing in the home has one massive advantage and that is no greenhouse fuel bill, but minimum temperatures need to be monitored at all times. When the central heating goes off you need to make sure the temperature doesn’t drop to excessively for the orchids you have, if it does then you need to make changes. This could be a independent electric thermostatic radiator for example.
What is wise is to know what conditions you have before you purchase any plants, they say Phalaenopsis (Moth orchid) are ideal house plants; well they aren’t if your house gets too cool at night.
You could say any orchid is ideal if you have the right conditions for the orchids you intend to grow, lets look at Phalaenopsis for example as these are popular house plants mainly because they flower for such a long period so are great value. They seem to tolerate the drier air but do watch the temperatures as they are true warm growers requiring minimum temperatures of 18°C (65°F). They do tolerate short spells of cooler temperatures, but wouldn’t risk going below approx 15c/(60f) for long periods. Being cool and wet for Phalaenopsis is a terrible life threatening combination you don't want to promote.
Choose a bright room and keep the orchids away from direct sun which will scorch the leaves, windowsills are not really the best location as temperatures can fluctuate too much. If your windowsill is deep, like a bay window then this will be a better option as the plant is more in to the room. If the only place you have is a windowsill then move the plant at night in to the room, but make sure the plants don’t get direct sun especially in summer; you have been warned! UK winters are ok as the sun is very weak but as soon as the sun gains strength and produces heat on the leaves then revaluate your situation.
It is best to water with tepid water and when you do pour lots through the pot, then let the water drain before placing back into any decorative pot. Tap water is not recommended if it's not soft but can be used if you've got no choice, It's best to let it stand for 24 hours. Pure water like rain water or reverse osmosis is best with a proper orchid feed that contains all necessary nutrients including Magnesium and Calcium.
To make watering easier and to prevent water spillages it is a good idea to have a drip tray filled with gravel, you can sit your plants on the gravel but make sure the orchids are not sitting in water or have a grill above the gravel for the orchids to sit on. You could also use Leca (clay pebbles) instead of gravel. The drip tray may provide a tiny amount of localised humidity but I personally don’t think it provides enough humidity to warrant it even being called a humidity tray as some put it, but they look good and serve a practical purpose.
Orchids in the home will benefit from a regular misting as centrally heated rooms can be dry at times, just make sure you don’t leave the plant wet at night especially in winter so it is best to mist in the mornings.
Feeding in the home is no different to my feeding guide, but I think most orchids grown in the home get neglected in this area by most so give your orchids a regular orchid feed. I would personally recommend Akerne's RAIN MIX® that can be purchased through the website. If you choose to use any plant feed which I wouldn’t personelly recommend then, a weak weekly feed would be very much beneficial or feed at 1/4 strength of the recommendations.
I would personally also endorse Orchid Focus feeds and Orchid Myst. Orchid Myst is great for times inbetween full waterings when the surface is dry but a full watering isn't yet needed, don't get caught out and kill the roots by drip feeding water. The chances are the water will run straight through the potting mix and sit in the bottom of the decorative pot cover and rot the roots.
Soak, drain and don't water again until the potting mix is dry throughout or the roots have turned from green(watered) to silver(dry).
Keep a misting bottle to hand with the water/feed ready for action for misting or surface spraying of roots! Or use Orchid Myst.
Hope this has been of help.