Dealing with a colder room

timccarpenter

we have a 100 year old house with cast iron radiators. Our kitchen is always a couple of degrees colder than the rest of the main floor. I checked with a contractor about installing a larger radiator in the kitchen ($$$$). He suggested turning down the 3 large radiators in the rest of the main floor. Theory is that that will allow the kitchen to get warmer before the radiator is satisfied in the living room. Wouldn’t this be less efficient? Would the boiler end up working harder to get the main area to temp? Is this a viable idea?

Jamie Hall

Well that's exactly what I would do… assuming I couldn't reduce the heat loss from that room in the first place. And assuming this is hot water heat, not steam (the solution is different for steam, but the same principle).

And no, it will not make the system less efficient. The boiler may run slightly longer, of course, but at the same efficiency. The slightly longer run just puts more heat into the house — which is the objective of the exercise, isn't it?

ethicalpaul

Just to clarify, the contractor wants to try rebalancing the radiators before spending $$$ on a new radiator, right?

timccarpenter

the contractor is suggesting I try the rebalancing first.

Wouldn’t the boiler running for a longer period to reach the desired temp (due to closing radiators a bit) be more costly?

delcrossv

No, because the heat is still going into the house, you're just rearranging where it goes.

(Actually the rate it's being distributed between the various rads)

A balanced system should reach setpoint in every room at the same time.

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1815597#Comment_1815597

Not really. The boiler may call for heat longer and the circulator pump may operate for that extra time, BUT, the heat will go the the radiator that is being cut down and return the the boiler without putting that heat into the room. That unused heat can then go the the radiator(s) that is too small during that time.

Now here is the kicker. Since the heat didn't go the overheat any rooms while you were getting the kitchen up to temperature, that heat returned to the boiler, the boiler water temperature increased as a result. That heat made the water get so hot that the high limit shut off the burner. But the circulator pump is still putting the hot water into the kitchen and the other rooms at a lower rate even though the burner is not burning any gas (or oil). Think of this as free heat for that time that the hot water is circulating and the burner is off.

There is the reason it will not waste fuel.

Your home will only use the fuel necessary to satisfy the thermostat. if it takes longer then the high limit will turn off the fuel while the home catches up.

The concept of turning down the flow in a radiator to make another radiator do more is hard to grasp. I find it easier to put the thermostat in the room that is the coldest. That will make the other rooms overheat. (and that is wasteful) so you turn down the rooms that get too hot until they are comfortable. That seems to make more sense to folks. But you don't need to move the thermostat to adjust the valves…. you can do it the counterintuitive way until the kitchen gets where you want it

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1815597#Comment_1815597

Yes. running the boiler long enough to make your house comfortable is more costly than not running it long enough to make your house comfortable!

EdTheHeaterMan

Yes. running the boiler long enough to make your house comfortable is more costly than not running it long enough to make your house comfortable!

Always the philosopher @ethicalpaul




HVACNUT

Get a thermostat with one or two wireless sensors, and average them with the thermostat. You could potentially have three points of sensing. You can sense from the wireless sensors ONLY if needed.

You don't even have to permanently mount the sensors until you've found the Sweet Spot.