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October 16, 2009
Unbalanced Heating in 2-Family
We live in a steam heated 3-story, 2 family brownstone & rent out the top floor. It's cozy downstairs, but frigid upstairs. The difference can be as much as 8 degrees. I was told the top floor is usually warmer than the bottom. Any advice would be greatly appreciated.
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You can take a bunch of steps yourself. Your goal is to figure out whether this is a balancing or sizing issue, or something else.
First, when the heat goes on, do all the radiators heat up together, or do the top radiators heat up much mroe slowly? Second, how long does the boiler stay on once the thermostat cals for heat? The whole time until temperature is reached or does it cycle on and off a lot?
If it cycles a lot, make sure you are draining the dirty residue water regularly. Drain it all the way until the boiler shuts off, then shut the spigot and wait to make sure it automatically refills itself with new water from the water line.
If the top floor radiators are slow to heat up, try larger vents on the top floor radiators (Gorton C or D) and smaller ones downstairs (Gorton 4 or 5). You want larger vents up top to draw the steam up faster from the boiler. Make sure you change the vents when the heat is off, and wrap the threads of the new vents with teflon tape before you screw it in. (The vents are the little thingies that stick out of the radiator at the far side away from where the radiator conencts to the pipe.)
If you are still way out of balance, check your radiator sizing. Heatinghelp.com has sizing charts based on cubic footage of the room.
If this is all over your head, or if none of this solves the problem, call a plumber. I recommend John Hlad or Gateway.
Posted by: slopefarm at October 16, 2009 11:08 AM
One simple thing to check (and you may have done this already so ignore me if you have) is where the thermostat is. Often time, it is on the top floor in the vestibule area of a building and doesn't necessarily kick on when it is colder downstairs than the setting temperature.
Posted by: mabilon at October 16, 2009 11:31 AM
Have similar problem with my 3 story. Top floor radiators cool while downstairs toasty.
Crank the heat, check which radiators go on. Air goes to highest point and can block the heat from top radiators. Mine just needed bleeding and worked fine shortly thereafter.
Even when running perfect there's a bit of a lag for heat to make it to top floor, but only a few minutes.
Posted by: Johnny at October 16, 2009 11:33 AM
Never mind. I didn't read your post carefully... SOrry.
Posted by: mabilon at October 16, 2009 11:33 AM
I spent months figuring this out last winter. My attic too was freezing, and other rooms were way too hot. Generally plumbers can't do the best job here, simply because you need a lot of time (hours/days/weeks, over various outside temp changes) to see the true effect of any adjustment. Changing the air valve sizing on your radiators is key, (assuming your boiler and thermostat are both fine). It's a bit of an art, because changing the vent size on one or more radiators changes the pressure balance, and hence temperature at every other point in the system. I ended up using a combination of Gorton, Varivalve, and Danfoss adjustable valves (with either Gorton or Varivalve air vents instead of the stock danfoss vent) to get exactly what I wanted. There are a lot of resources on the web to help you figure it out, but it takes patience and persistence, and you will probably end up buying more valves than you need, just so you can get the balance correct in the end. It's well worth the effort and acquired knowledge to be able to do it yourself. BTW, don't listen to Johnny - there is no such thing as "bleeding" a steam system. That concept only applies to a hot water system.
Posted by: wyckoff at October 16, 2009 11:57 AM
Seconding the recommendation to "Bleed" the radiators throughout the house. Trapped air is probably keeping the steam from getting to the upper floor. It's relatively simple, but done better by a couple of people. Have your plumber come do it (and do an annual inspection/tune-up of the boiler). Bleeding the radiators makes a HUGE difference, everything will be much more efficient and you'll be able to adjust the thermostat down (no matter where it is located).
Posted by: pkellogg at October 16, 2009 12:13 PM
Forgot to mention - Think about replacing the vents on your steam mains in the basement (they should be located at the corners where the steam pipe goes vertical into the upper floors) with proper ones like the Gorton Air Elimators -- it will make a HUGE difference.
Posted by: wyckoff at October 16, 2009 12:14 PM
Since someone else "seconded" the recommendation to bleed, let's review how a steam system works, so you don't chase down blind alleys: 1) Flame in the boiler heats the water to a boil in the furnace. 2)Boiling water creates steam, and resultant pressure. 3) The steam, under pressure, looks for the easiest way out -- which are air vents on your radiators. 4)Steam travels to the vents, pushing out the air in the pipe in front of it, through the vents. The bigger the vent, the more air can escape, and the faster the steam will go to that vent. 5) Once the steam itself reaches the vent, your radiator will be hot, and the pressure differential will close the vent, blocking more steam from the radiator. 6) As the steam cools it turns to water and runs back down the pipe and back to the boiler for another cycle.
This is very different from a hot water system, where air bubbles can prevent water from circulating through the system, and as such, air needs to be "bled" from the system.
Posted by: wyckoff at October 16, 2009 12:33 PM
The best way to get an old steam system in a big house working perfectly is human sacrifice.
Posted by: Brenda from Flatbush at October 16, 2009 1:21 PM
as what slopefarm said.... radiators need to be 'balanced' - this is release valves on the radiator with larger openings furthest from heat source and smaller one closer to it (meaning your apt -)...If this is a newish problem maybe that release valves are clogged upstairs and need to be replaced.
ANy heating/plumbing company can do -- or you can google and get info...draw a chart where your boiler is and radiators are - and also find a helpful plumbing supply store guy if DIY person ( this is nor rocket science).
Posted by: Petebklyn at October 16, 2009 3:18 PM
Brenda nailed it. Works EVERY time.
Wyckoff, you've got a fine understanding of the process of steam heating for a (I'm assuming) non pro.
Except one thing. The air vents close when steam reaches them because they're filled with fluid that expands and closes the air passage.
It's a temperature thing, not necessarily a pressure thing (though high pressure can close them too). Good work!
There are other factors that determine balance, lately the most common one I see is everyone's brand new fancy schmancy programmable thermostat is factory-set to work with a forced air system (something like 85% of US homes are heated with forced crappy air), which requires shorter, more frequent cycles than steam.
Find the anticipator setting or the one that says you're using "hydronic" or "water-based" heating.
Me:
http://www.GatewayPlumbing.com
Posted by: Master Plvmber at October 16, 2009 6:38 PM
master plumber... i had to do exactly that today, because the client had replaced the thermostat himself..who the hell in nyc has forced hot air ( burnt air)
Posted by: eman1234 at October 16, 2009 9:57 PM
Only in the NE do you find hidebound opinions like the two above.
if you think about it, there's a good reason "85% of US homes are heated with forced [crappy] air"...because it's cheaper to install, it's comfortable and it responds faster. You will note that many 'luxury' new apartments have forced air.
Posted by: cmu at October 16, 2009 11:44 PM
Yes, cmu, dirt-collecting ductwork and seriously deficient relative humidity are wicked awesome features in a "luxury" home.
Ever see sales literature for a "luxury" home? Wonder why a water-based heating systems are an upcharge?
Keep 'em coming. Your opinions are gold.
Posted by: Master Plvmber at October 17, 2009 12:54 AM
Your opinions, MP when you stray from your undoubtedly excellent technical knowledge, are...shall I say, not always justifiable.
Your example merely shows that *marketing* a system can influence its choice. Luxury condos nowadays are beginning to use the Unico high-speed duct system (obviously less efficient, but less obtrusive also).
Funny how all those Western and Southern homes are contentedly living with dirt-filled ducts and burnt air and inferior heat. Guess we are just more sophisticated in the Northeast.
Posted by: cmu at October 17, 2009 10:28 AM
where would I find this anticipator setting on thermostat to check , Master Plumber?
Posted by: Petebklyn at October 17, 2009 1:46 PM
cmu, with all due respect (you're obviously an intelligent and educated gentleman), those western and southern homes are in climates that aren't nearly as harsh as ours in New York and New England. They use lesser heating systems because their demand allows it.
Petebklyn, I'm sorry I couldn't say. All thermostats have a different way of setting the anticipator.
Posted by: Master Plvmber at October 17, 2009 8:05 PM
You have got to obtain the book "The Lost Art of Steam Heating" by Dan Holohan. It will answer all of your questions. Many plumbers are very ignorant of how steam systems work. You can arm yourself with knowledge.
And please, please, please, if you heat with oil, do not settle for a "tuneup" that is not done with combustion testing equipment. An oil burner CANNOT be serviced safely or efficiently without instrumentation.
Posted by: elias at October 29, 2009 2:05 AM
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