Undersized Radiator

nycpa

Hi,



I have a remodel radiator that is recessed into the wall in my living room.  I attached a picture of it.  The problem is the living room is always cold in the winter.  The radiator appears to be a bedroom sized radiator.  If I increase the temperature, all the other rooms get too hot, there is an easily 5 to 10 degree difference from the living room and the rest of the house. What solutions would be available?  I was thinking of adding a extension of the pipe in the wall to the outside of the wall and connect it to one of the newer types of radiators that look like baseboards but are steam baseboards and get a long one that goes across the entire back wall.  Would this some how mess up my steam system?  Cause banging in pipes?  I guess my other solution would be adding a electric space heater? 



Thanks for the help.      

Hap_Hazzard

First make sure it's working properly

Is the radiator heating up as quickly as the others? Is it getting hot all the way across? What type of system do you have (i.e. one-pipe or two, etc.)?

nicholas bonham-carter

Cold living room

If that is the original radiator to the room (and therefore correctly sized), I would see if there is a venting problem, which is getting steam to that radiator later than the others.

For a test, turn off the heat completely, for a few hours, and then set up the thermostat to above normal. Check the temperature of all the radiators as they heat up to see if they all get steam at the same time ( including the problem child).

Look on your mains for some main vents, and replace them with bigger ones.--NBC

BobC

i have one of these

in my bathroom and for a little radiator (less than half your size) it puts out a lot of heat. I agree with the other information you have been given but here are a couple more hints.



These are really a convector so free air movement is importtant. Remove the bottom grate and use a radiator brush to get behind it and fish out any dust you might have hiding out of sight. I assume this is on an outside wall, can you tell if there is any insulating board behind it (so the heat doesn't just escape through the exterior wall)? Assuming the radiator does heat all the way across, does the wall above it feel hot? There should be some blocking inside the wall above the radiator that forces the heat out into the room instead of allowing it to go up the wall cavity.



Where is the thermostat in relation to this or any other radiator. A lifetime ago I lived in an apartment where the thermostat was on a short wall between two doorways and across the room from the radiator for that room (this room was on the north side). That room was always cold even though the setup seemed fine. I finally realized a steam pipe to the second floor ran up that wall and every time that apartments heat came on mine went off because the thermostat sensed the heat in the wall.



Bob

nycpa

Responses to Questions

The radiator is definitely not an original radiator.  I can see the hole in my wood floor (now capped)  where the original one was a few feet away.  Prior owner moved it so he can install floor to ceiling window.  I tested the windows and it doesn't seem to let cold air in.  The main vent I have in the basement is the original main vent i think.  Have never touched it.  I have a one pipe steam system and the radiator does get hot.  When I installed the Gorton vent on the radiator, we drilled a bigger hole to allow more air to vent.  There is insulation behind the radiator, I can see the foil fiberglass.  The wall right above doesn't seem that warm.  I will clean it out from the bottom right now.  The thermostat is opposite of this radiator, no steam pipes near it, though it is closer to the kitchen. 



Thanks for the help guys. 

JStar

Rad.

Don't tee off of the existing radiator to install another one. You'll be more likely to cause problems, rather than adding heat.



You should have a heat loss done on the room to see what amount of radiation is actually needed.

Hap_Hazzard

Another option

If it really is the case that this radiator is too small, and you can't achieve a reasonable result by balancing, there is another possibility you might want to consider for getting more heat into that room.



If you have access to the floor under the living room from your basement, you might be able to install radiant floor heating and heat it via a hot water loop that takes hot water from your boiler and circulates it under the floor. This approach is attractive for several reasons. First, it won't take up additional space in your living room, all the construction will be done in the basement so it won't disrupt your life, and it places no additional EDR load on your boiler.



A fin-tube baseboard would add to the connected load, so you'd need to make sure your boiler can accommodate it, and it would take up space in your living room. Depending on how it's installed it might also require piping in the basement that would impact the useful space (and impact your head if you're not careful). Radiant heat uses smaller piping, pitch doesn't matter, and it can even be done with special PEX tubing.



Also, fin-tube baseboards are very light, and they don't have the mass to hold much heat. They heat up very quickly, but when the steam stops flowing, they cool down just as fast, so you would notice temperature fluctuations. Same radiant floor systems have metal plates that help distribute the heat and add to the thermal mass, and if it's done right, they will insulate the joist bays so heat can only escape upwards, and the tubing, the water, the plates and the floor itself will retain heat for a long time.



This is something I'm considering for myself, but I'm still in the research phase. I'm assuming I will need to call in a professional at some point because it requires a lot of expertise I don't have time to acquire, and I can see that there are a lot of points where I could go wrong even though I'm a pretty advanced do-it-yourselfer. If you think this might be a workable solution for you, you might want to run it by a professional who can come out and assess the situation.

nycpa

Thanks for the idea

I didn't think of radiant heating.  That was a good idea, I didn't know baseboard has those heat characters.  The basement below if finished but unheated.  I guess I can cut out the sheet rock and put radiant heating between the joist.  My other questions are;



1) Can a pump be that strong enough that it can circulate the hot water in the boiler forty feet across then seven feet up?



2)  Would it be a better idea to heat the basement?  Would that be a better idea to heat the finished basement room underneath and that heat might warm up the living room?



3) Is it possible to heat the basement with baseboard and make another connection for radiant heating or even adding baseboard to the living room?



4) Would a better option be just to install those AC/Heat mini split system in the living room and have two sources of heat in the living room?  I am thinking this might be the most cost effective method?  Cost would be around $2000 to $3000 dollars.  I am assuming radiant heating will be a lot more? 

Hap_Hazzard

To the best of my understanding...

1. Yes. This is how forced hot water systems work. The main challenge in doing it with a steam boiler is having a pump that's powerful enough to do the job without cavitating, but there are some tricks that the pros know.

2. As Rocket J. Squirrel used to say to Bullwinkle, "that trick never works." Somebody thought they could heat the first floor of my house by cutting holes in the floor and letting the heat from the uninsulated steam pipes in the basement rise up. There was always about a ten degree difference.

3. This depends on the size of the boiler. You have a 30% "pickup factor" to work with. If you need more than that you may need a bigger boiler, unless you have a little unused EDR you can tap into. It might be enough just to leave the radiant loop uninsulated, which would lower the cost of that installation, but a pro would be able to advise you on that.

4. I wouldn't think the radiant would be that expensive, but I might be in for a rude awakening. You'd have to get an estimate from a pro who can come out and do heat loss calculations and measurements and advise you on your options.



We aren't allowed to discuss pricing on the forum, but if any of the pros here work in your area they could discuss it with you privately. I will definitely be using one of these guys when I get ready, but I have a lot of work to do first.

nycpa

t h anks

Thanks for your help, I guess I'll leave the radiator in place, will look into radiant heating

Paul48

Agreed

There's  room for a larger radiator there. Do a heat loss and get back to what you had in the beginning. Why complicate a beautifully simple system?