Orchid blooming question
 

Hello,
Growing many houseplants before getting into orchids I know that some plants require a 4-6 weeks period of significantly lower temps in winter to form the blooms.
It is really hard to achieve here, when your house is evenly heated during winter times.
Are there any orchid species that would require this for flowering?
Thank you.

Bulbophyllums for sure.

Certain Phalaenopsis. It's easier to manipulate Phals into blooming at any given time of the year though.

Several Dendrobiums need a cool dry period to trigger blooming.

which phals need winter rest, if you don't mind my asking?

Orchideya didn't specifically mention winter rest. She just mentioned a dip in winter temperatures.

Many Phals need that to bloom.

If you're asking for winter rest, Phal lowii for sure. Perhaps Phal braceana, Phal taenialis, and Phal wilsonii as well. But keep in mind the winter rest is not a completely dry dormancy. Winter is just drastically reduced moisture for the ones I mentioned. The thing with these is that Phal lowii can go deciduous under certain conditions, and all the others go deciduous if they develop leaves but they're usually "leafless".

For Phals I find the natural drop in temps late in the year is enough. I don't have central heating on all the time so the house drops in temp naturally and that is enough to trigger them.

Actually here we had a really warm April then it went cooler in May. I have spikes on about 50% of my Phals that started then.

With some others I keep them in the greenhouse over winter, but those are orchids which like to go properly cold (I keep the greenhouse at about 5C/41F over the winter). Things like my Cyps are outside all year and get snow and frost on top of the pot in winter. I've heard they are one that needs to go REALLY Cold.

Growing your phals near a window will often give them enough of a chill.

In terms of hybrids, most of the plants in the white/pink/mauve colors tend to respond to a period of cooler temps, while those in the yellow/red range do not. Like all things orchid, there are exceptions, especially if you consider the complexity of hybrids.

Yes, I grow phals close to window and they re-bloom without additional effort. They are noids.

What about vandas? Besides bright light is there anyhting special that is needed for them to bloom?
I have got a blooming sized V.Roberts Delight 'Garnet Beauty', it hangs on the east-south window, where it gets morning sun. It grows new roots and looks healthy.
What could I do to induce blooming?

I guess I meant drop in temps like the OP. I am sstill learning the lingo around here and made a mistake. Sorry!

Vandas - I grow all my vandas without a drop in temps (indoors under lights) and have not had a problem reblooming. My experience so far indicates that a failure to bloom is usually a result of not enough light with vandas.
Some vandas bloom only once a year.
Someone here posted a Garnet Beauty recently - you might ask in that thread as well for specific advice :-)

No worries. :) The reason these distinctions are made is because the orchids themselves behave in such a specific manner that is often times very unique. It's often difficult to describe things because at the moment I'm not sure if there are any words or vocabulary to describe the concepts easily and concisely. Everyone learns and everyone makes some kind of mistake in some form or another and to some degree or another, but it doesn't matter unless there's learning happening. ;)