Candle Convection Heater- Winter Camping with my Off-Grid Stove! (Snowmobile Camper Series)
Opinion/Comment: Some great suggestions and ideas below – add your own
Instead of making the air intake larger, you could add another inline fan to boost the airflow. It would be easy to make the fan speed variable with a rheostat or a variable voltage regulator. Instead of multiple candles, you could use an oil burner with several wicks. That way you could ensure that the flame is at a constant height and you could easily add oil without opening up the stove.
Ben There
If you increase the intake pipe, remember the incoming air is denser than the warm exhaust and it actually needs to be larger than the intake. Restricted outflow might be why you can’t keep more candles burning. Have a great day.
Jerry Stott
This is great! I think you can improve a bit by making a mechanism to keep the burning top of the candle at the correct height, similar to the UCOGear candle lanterns (https://www.ucogear.com/candle-lanterns/). All you would need is a top plate with contours to hold your candle tops attached to two side rails which are attached to the base of the ammo box. Make sure the rails have a central channel through them and add a base plate with lugs that go through the channels. attach some thumbtacks with JB weld to the base of the plate to hold the bottom of the candles steady and then two light compression springs between the base plate lugs and the top plate. As the candles burn, the bottom plate can rise. You could build this completely out of aluminum L brackets, screws, and JB weld. The trick is getting the spring tension equal and just strong enough to pull the candles up. (which will need less force as the candles burn and lose weight.) Use good quality wax candles and they should last a good long time.
David Bartolini