baseboard temps

jp_2

to properly heat the room!

nbmech

baseboard temps

Is there a rule of thumb for the actual temp of my baseboard heaters?
The boiler shuts down at 190 degrees and using an infrared thermo I checked the outlet pipe and it is close to 190. The inlet side is between 160 and 175 degrees, depending on which zone is on. I guess this depends on the length of the zone. The base board heaters are between 75 and 90 degrees

Mike T., Swampeast MO

Your system would seem to be following the "rule of thumb" which finds a 180F "base" temperature with a control with a plus/minus 10F differential. In other words it starts firing at 170F or below and stops firing at 190F or above.

For a conventional (non-condensing and non-modulating) boiler, such is likely the most appropriate setting as it [should] allow the boiler to operate in its most efficient range as much of the time as possible. This does of course assume that the boiler is well-sized compared to the baseboard emitters.

Lowering the temperature (as jp suggested) either by manual or automatic means, does not necessarily mean that there will be much--if any--energy savings with a conventional boiler and if you go too low (either manual or automatic) you risk condensation damage to the flue and boiler.

Condensing/modulating boilers are completely different beast and your fuel bill WILL benefit (often greatly) by using the lowest possible temperature across the greatest length of time.

jp_2

180F

what makes 180F a magically effiecent temp for a boiler to run(cast iron)?

Mike T., Swampeast MO

I won't say that there's anything "magically efficient" about 180F average supply temp, but do remember that conventional boiler manufacturers used this "rule of thumb temperature" for many decades, just as they used plus/minus 10F operation and 20F delta-t in the emitters.

Particularly with low mass, highly convective emitters such as fin baseboard, such is darned easy as long as you pipe appropriately considering the available circulators.

I do like to think that manufacturers consider the systems in which their boilers will be installed and will design them to operate most efficiently given the long-standing "rule of thumb" design ideals.

Supply House Rick

Condensing Boiler w/baseboard

Someone posted this before. Good information...

jp_2

my guess

is that hot water systems followed steam systems. so they used existing steam rads which required hi temps.

why are we calling boilers, boilers, when they never boil water. though a steam boiler boils water.

remember, simple physic requires more energy for hotter system temps. so even if efficiency were to fall a bit, the required energy also drops for a lower system running temp.

therefore I put money down stating a boiler running at 160F is more efficient and uses less energy than running at 190F.