Aluminum baseboard vs. cast iron
I’m considering replacing my old aluminum baseboard heaters (hot water heat) with cast iron baseboards – partly for looks and hopefully for some efficiency. I haven’t priced it out yet, but I’m wondering if the cast irons really will be more efficient and will be worth the switch. Something like this by slant/fin http://www.slantfin.com/product-rhino-cast.html. Anyone…
I’m considering replacing my old aluminum baseboard heaters (hot water heat) with cast iron baseboards – partly for looks and hopefully for some efficiency. I haven’t priced it out yet, but I’m wondering if the cast irons really will be more efficient and will be worth the switch. Something like this by slant/fin http://www.slantfin.com/product-rhino-cast.html. Anyone have experience doing this?
Regardless of the makeup of the baseboard/radiator one of the best ways to make any baseboard/radiator more comfortable is to use a weather responsive control or Outdoor Reset Control. These controls change the temperature of the water inside the radiator based on how cold it is outside. The effect will be that the heat is on longer but at a lower temperature, you will smooth out the peaks and valleys between heat up cycles AND your system becomes more fuel efficient maybe 10-30% better(depending on several factors). The only company that I know of that has real data on the efficiency of hot water radiators is this one below.
You can read for yourself the tests and reports on their website.
http://www.jaga-usa.com/ especially look at the low H20 models if you are looking for efficiency.
Cast iron radiators absorb and release energy (heat) in a slower and more-controlled way over a longer period of time.
Because of this, in most cases, they produce a more narrow room temperature swing (warm to cool to warm) than radiators of thinner-metal construction.
That said, they often produce more comfortable results.
Sometimes they even increase or decrease *seasonal* efficiency (much different from combustion efficiency).
But everything depends on how the rest of the system is piped and controlled.
So while their is some validity to the question of which radiator will produce a more efficient condition based on the system design, on their own, one radiator can make no claim to higher efficiency over another.
http://www.GatewayPlumbing.com
Cast iron radiators absorb and release energy (heat) in a slower and more-controlled way over a longer period of time.
Because of this, in most cases, they produce a more narrow room temperature swing (warm to cool to warm) than radiators of thinner-metal construction.
That said, they often produce more comfortable results.
Sometimes they even increase or decrease *seasonal* efficiency (much different from combustion efficiency).
But everything depends on how the rest of the system is piped and controlled.
So while their is some validity to the question of which radiator will produce a more efficient condition based on the system design, on their own, one radiator can make no claim to higher efficiency over another.
http://www.GatewayPlumbing.com
Do cast iron baseboards really take much longer to heat up than aluminum fins? If I turn the heat on, the cast iron get hot pretty fast-maybe one minute longer than the old aluminum ones. I have not noticed the difference in warming up, but I have noticed the difference that the room stays warmer longer when the heat turns off. So if I made the room too hot, it takes longer to cool down. I’d rather have that problem than the other way around.
So the radiators being equal, I guess it is really important to consider the boiler performance and controls. Based on my knowledge (which is pretty basic) a system that fires on and off more frequently is one that uses more fuel than one that fires less frequently.
I replaced all the fin type radiators on my first floor (about 4) with one long cast iron radiator. It juts out from the wall by about 2 inches and works great. Much more attractive than the fin radiators and can be painted to blend in with the wall. I think it’s a Burnham but was brought to me by my plumber. I’m very happy with it.
If you go with aluminum fins then I would suggest Multi/pak 80 over the standard slant fin. Cast-iron will take longer to heat up and will take longer to cool down, aluminum will heat up quicker and lose heat quicker. They will both provide the same heat. There are advantages to both, like for instance when you come home from a trip in the middle of winter and turn your heat on, with aluminum fins it will heat up quicker. One thing that might influence your decision is that there are lots of designer cast-iron baseboard styles.
a66, I know a bit about metals, and it seems to me that there is no difference, like MP says. I could be wrong. If aluminum heats up faster then it is using less energy to do so, therefore the boiler would shut off sooner as the alum reaches the appropriate temp. Then the alum heats the room faster, but the boiler has to come on sooner as the alum loses its heat.
Conversely, it takes the cast iron longer to heat up (boiler runs longer), but longer to discharge the heat (boiler comes on later).
Therefore, we are back to what MP says, rads are 100% efficient, mat’l doesn’t matter.
I’ve read the same about cast iron vs. aluminum being equally efficient. I changed mine to cast iron because I didn’t like how dust and pet hair get caught in the fins. My experience is that the room feels warmer for longer. I have no scientific proof. I just have the plain cast iron baseboards that came primed gray and I painted them brown. They look nice, pets love them. Supposedly they take longer to heat up than the aluminum ones, but mine seem to get hot pretty fast.