Hi everyone,

I have a dendrobium orchid (indoors) which we bought when it was in full bloom. The flowers are slowly falling off and I don't see any new buds.

I wanted to find out, does this bloom throughout the year? I already plan to add charcoal to the mix, anything else that I should be doing to ensure we have new buds?

Your Dendrobium is a Phalaenopsis type. It generally flowers once a year. It blooms from old canes and new ones.
It needs to be kept well watered and warm. Allow it to dry a bit between waterings but it should not go bone dry for too long. They like monthly application of fertilizer when actively growing.
Prefers a couple of hours of sun per day, likes temperatures 60-85. Repot every 2 years with new media. Avoid pots that are too large since they like to be in small containers and tightly packed at the roots.

And here is some "good news" I have seen this type of Orchid in Bangkok tied around tree trunks in some main streets to naturalize them. They looked great!

Around here, if your plant grows into a large specimen, flowering will last for months. So in your climate it should do very well.

Ursula, you could grow orchids better then in their native habitats!

Thank you so much. Also, another question, I read that these need indirect sunlight. I have placed this indoor on the window ledge which receives afternoon sun through semi-tainted glass (this is in our office). This should be okay right?

You can not make that assumption! The Dendrobium family of orchids is one of the largest groups within Orchidacea with over 20 sections and a few hundred species. Cultural conditions naturally vary.
In brief, you have a " Dendrobium Phalaenopsis" type. It is warmer growing 65-85 degrees. It likes to be watered well and dry out between waterings. It needs a few hours of direct sunlight in order to bloom properly.
That is it in a nutshell. They like weak fertilizer perhaps every other month. If you need further information just let us know.

The key words here are "direct sunlight" which your orchid will not get through tinted windows, unfortunately.

You may want to take it home or find a better place to grow it, where you can give it better light conditions. Somebody with a terrace or lanai that faces the morning sun (eastwards) might let your orchid "camp" there until it starts to show buds again.

Without enough sunlight, it's very doubtful you will see more blooms no matter how well you care for it.