Baseboard Hot Water Heat Diverter

We have baseboard hot water heat.  In the baby's room his bureau obstructs nearly half of the baseboard heaters in the room.  Since the bureau is topped with bookshelves, it traps the heat against the outside wall.  Typically its not an issue, but in the dead of winter when the temp drops below 30 and goes far lower at night, his room can get to five or six degrees colder than the rest of the floor.

Rather than move the bureau which would mess up the decor and flow of the room, I decided to divert the heat from behind the bureau into the room.

I made an assembly out of some Reflectix insulation I had lying around, using computer fans, and a temperature controller.  The assembly sits on top of the heater behind the bureau suspended by 6 command hooks.  The temperature controller is set to go on at 75 degrees, with the sensor placed inside the baseboard heater.  So very quickly after the heat goes on, the fans start spinning to move warm air from the heater, around the bureau, and out into the room.  A nice feature of this setup is that the fans continue to spin until the temperature at the baseboard returns down to 75 degrees, so long after the heater turns off, the diverter continues to blow warm air into the room.

Results were good.  After 30 minutes the room is 28% warmer using the diverter than without it.  In the middle of a cold night, the room is generally not more than 2 degrees colder than the rest of the house.  When the heat comes on, it heats quicker, and stays warmer for a longer period of time.

Materials:

• Reflectix Insulation
• Duct or foil tape
• Computer fans (I used 3ea 120mm)
• 12V power supply
• 12V molex extensions
• Inkbird ITC-308 temperature controller
• Zip ties or elastic cord (1/8" shock cord)

1. Measure how long the piece of furniture is that you want to divert heat around
2. Cut a piece of Reflectix long enough to pass along the length of heater you wish to divert.
3. Form the Reflectix into a U shape for the length of the heater
4. Fit the computer fans into the Reflectix and secure by cutting holes or slats in the sides of the Reflectix and securing by wrapping around with the zip ties or elastic cord
5. Daisy chain the fans to each other using the Molex extensions
6. Create a mating piece of tube made of of Reflectix to wrap around, or go underneath the furniture, exhausting into the room
7. Connect the one of the fans to the 12V power supply
8. Connect the 12V power supply to the Inkbird controller
9. Set the Inkbird controller to come on 5 degrees warmer than your highest thermostat setting

There are a number of variations that could be done.  If you didn't have Reflectix you could potentially fix the fans directly above the heater and fit a piece of cardboard on top moving the air over the heater and around the furniture.  Instead of cardboard you could use plastic gutter.  You could use aluminum dryer ducting to go around the furniture.  

I also used 120mm computer fans, but think 90mm may be better for a lower profile or to mate with aluminum dryer ducting.