heat powered fans for stoves, etc...

We have a steam boiler in a VERY old house. It's in the cellar. The cellar is pretty drafty and I'm working on that. Additionally, I'm overwintering a number of plants down there. I'd like to spread the heat rolling off the top of the boiler a bit(to areas with plants, water pipes, etc) and have seen numerous heat-powered stove fans. However, the designs are many. Has anyone seen a comparison of the various heat-powered fans? They cost too much for me to buy a mess of them and test.

Heat powered fans require a flat surface and temperatures hot enough to fry an egg at least. Does your boiler have that?

IMO there's nothing wrong with using a small, efficient multi-speed electric fan for such tasks.

Thanks. The boiler top is flat. I'll have to run some temps but enough to cook an egg? Probably not. I thought about a small electric fan but the allure of something that does not require electricity is great. This is especially so since I'd also have to run a new wire and outlet in order to make that happen. Looks like I have some homework. ;)

I've heard of sterling engines that could run off the heat from someone's hand. That might be enough to power a fan, but I've never actually seen one in-person.

Looking around, there are fans that claim to start at temperatures below the boiling point of water. Shop around!

Personally, I am shameless about buying several models from big box stores and returning the ones that don't work out.

Edit: FWIW, I had one on my old wood stove and it made a big difference in diffusing the heat through the house.