I have hot water heat in my house, and a plumber told me that raising the baseboard radiators 1" off the ground (they are currently flush with the carpet) will significantly improve the amount of heat a room gets because it will have more efficient convection. Another plumber told me that doesn't make any sense. What's the right answer? Will it help?

Hi! royd10, welcome to AMHD :)

Cast Iron rads stand well above the floor, and I've never seen baseboard Hot water heat flush with the floor. Mine are 2" above.

The system is based on convection (hot air rises), and if the bottom of the Baseboard rad is blocked with a rug, it slows or even stops the convection, which in turn severely reduces the efficiency of the system, and it take longer to heat the room

K

What's the right answer? Will it help?

I would tend to believe the first plumber in principle, although without a computational fluid dynamics analysis of the room scenario, I'd be skeptical of the "significantly improve" assertion. Most of the radiator installation literature I looked at had the radiator installed above the baseboard or ~3-6" off the floor with Runtal's instructions (http://www.runtalnorthamerica.com/residential_radiators/baseboard_uf.html) allowing a minimum 1" finished floor gap.

I have an older 1940s built home in which the radiators were originally down on the carpet too. I've since removed the carpet in favor of hardwood floors, but I think higher installation is good if for no other reason than cleaning ease, however I would put in a ceiling fan for forced convection before tackling raising all my radiators.

Thanks very much - this was useful