Heating Questions - detailed

[stretch]

Alan,

You did say ONE PIPE STEAM, did you not? In that case ignore Eds answers, they are for hot water systems!

It sounds to me like you have a venting problem. If you are getting enough steam to the top floor apartments, then the radiator air vents will need changed in the cold apartments. Hoffman makes an adjustable radiator steam vent. By changing the oriface size in the vent, more or less air is let out of the radiator, allowing more or less steam into the radiator. That is how you control the heat from a one-pipe-steam radiator. That is, unless you prefer the "open window" method :-).

DO NOT try to controll the heat with the hand valve! That will make the system bang like someone with a jackhammer is inside the pipes! The hand valve must be WIDE OPEN for any heating. This is because on ONE PIPE steam, the steam goes into the radiator through the same valve and pipe that carries the condensate away. If there is not room for them to pass easily, the system will bang and hammer enough to wake the dead! The banging can also damage the pipes. The pipes from the steam main MUST go uphill all the way to the radiators. Any dips in the pipes will cause NO heat or banging. If you want thermostatic control in each apartment, there are thermostatically controlled valves available for the air vents from DANFOS. They are installed between the air vent and the radiator. They are fluid filled - non electric; so there is no wiring. Any heating company familiar with steam should be able to get them.

Stretch

[Alan Greenspam]

I live in a 4 floor- 8 apartment coop building (two aparments per floor, with a front and rear one-pipe steam heating lines) that is experiencing the following heating problems:

2 ground floor apartments are uncomfortably cold throughout the winter while the upper three floors are fine or too hot. There is one thermostat in the building one the second floor set at 72. If we raise the temperature to heat the lower floor, the upper floors overheat, so we are looking for solution that keeps the temperature at 72.

to solve their overheating problems, both second floor apartments have removed one of their radiators. one the third floor, one of the apartments gets too hot sometimes, so they do not want to do anything permanent, like remove a radiator. I have suggested an adjustable radiator valve (such as the vari-valve from heat-timer.com). Any good/bad experiences - shouldn't this work?

I have also suggested smaller size valves for any other apartments that overheating on the upper floors to reduce the amount of heat being released (as opposed to them opening windows). The ground floor apartments already have largest opening Gorton D size valves. The theory I have applied in making this suggestion, and would like someone with heating expertise to confirm or deny, is that if there is less heat being released on top floors, the boiler will continue to heat the building longer than it did before in order to get to the temperature cut off of 72 (and thus making the ground floor warmer).

[stretch]

Alan,

I forgot to mention that the smallest valve on one pipe steam radiators should be 1-1/4 inch. Putting too small a valve on will cause problems, In addition to banging, you will get water squirting out of the air vents! this is because the velovity of the steam entering the radiator is high enough that it will push condensate (Water) back into the radiator and leave it squirting out the air vent. The air vent on a one pipe system is thermostatically operated. If it is below 212 degrees, it will open to allow air out, If water is present, that will be allowed out also,

Stretch

[Edwin Pawlowski]

Yes, it will help. No matter what you do, the thermostat is going to control the boiler itself. When it is satisfied, the circulator will stop no matter what the other rooms are. If not, it will continue to circulate hot water. Restricting heat to the now too hot rooms will help with balance

Balancing eight apartments is going to be difficult at best. It is also probably using a lot more heat than needed because some it being wasted with open windows while others are trying to get warmer. Is the group willing to consider a large overhaul of the system? It may have been costly when the building was built, but today it is possible to zone each of the apartments. You need some review by a competent heating specialist that can evaluate the piping to see if it is easily zoned.

[Alan Greenspam]

Thanks for the reply. I don't think a large overhaul is on the horizon

- I am not sure what zoning means or entails (I can guess each apartment will be able to set its own temperature via a zone 1-8 on a thermostat?) . The main obstacle would probably be cost any estimates on that? Building is pre 1900's.

[Edwin Pawlowski]

Zoning requires that each apartment (or zone) would have a set of pipes to its radiators. It would have its own thermostat. When that apartment needs heat, the thermostat turns on a circulating pump that sends the how water just to that zone.

Given the size and age of the building, the cost would be very high, in all probability. Easily in the thousands of $$.

Thee may be some cheaper methods to get better balance. Even putting an insulating blanket over a radiator in the over heated spaces would help. It would block the heat from getting into the room and let it pass back to the boiler. Restricting vales or turning off certain radiators helps also.

[G Henslee]

Bad Ed. For your punishment you must go to alt.hvac for 24 hours and be severely beaten about the head and shoulders and have your arse hairs singed by the flames of hell ;o)

[m Ransley]

Well Nick of course you and your "humidification wates energy " posts now show your stupidity as releasing steam from the boiler is the dumest thing you can do for boiler efficiency. Your boiler then needs makup water at winters cold incomming temps which your boiler must now raise to steam.

Gee I treat my boiler water with nasty chemicals , so do many, and you want that crap to breath ! Maybe this explains your thought process, you are poisoned. Building owners strive to keep systems from Not leaking steam from defective vents, it is the simplest way to keep up efficiecy.

[nicksanspam]

I used one, along with a humidistat and solenoid valve to add humidity...

Nick

[m Ransley]

Alan if you are a tennant why worry. If you are the owner or manager you need to balance the system from top to bottom, time consuming, but as an owner it will save alot of money from not overheating areas.

First get your self a good IR thermometer like Rayteck not Radioshack, Rayteck reads the same tenp trigger to trigger, Radio Shack can vary 3 degrees on the same site. And 2 thermometers at least for each apartment that can be calibrated to one master by sliding the bulb, cheap Taylors. Mount them in the same location and same hight in each apt and record every room at same time walking through the building. This will show your imbalance.

If it is an apt you don`t want tennants to be able to control the vents so Gortons are good. Gortons come in many grades of venting, maybe

1. 2-3-4-5-C-D. You realy need the same design everywhere as in all Gorton or cross refrence the venting #. Cheap chinese are junk and don`t close evenly even though they cross refrence. D should only be used in difficult to heat areas as a last resort. Basicly it means taking a hot area and throttle it down to a smaller size and a cold area go larger. Since you have Ds in cold areas get smaller upstairs, What is upstairs now. Dole, Gorton ? Buy a range of 3- 4 -5 -C and start to lower the upstairs till the heat is more even. Also the main and return boiler feeds could have bad vents. Is the area hard to heat nearby or at the end, main venting will do this. It is a trial and error process. Removing radiators is a last resort that should have not been done yet as it imbalances everything. Also when you lower upstairs heat you will force more to the first floor through the Ds. You may end up removing the Ds also. It can take weeks of everyday checking and changing vents, be sure to keep a log of every apt and every change and temp differential noted as to where you started and results so you are not guessing. I just did my 16 unit it started with 10 degree differential now it is 2. With steam it never will be perfect and will vary from when it is -10 to 50f on eveness. A pro would charge alot for this as it is extremely time consuming and detailed work. What vents are in the building now? You need a list before you realy start to know what you need to replace. There are adjustable Dole 1-10, but the resident usualy cranks them then opens a window.

Old vents can be soaked in vinegar it usualy frees them up. Anything stronger like CLR can eat the plating.

[Edwin Pawlowski]

Crap, I missed that. You're right

[Edwin Pawlowski]

NNNNNNOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

Actually. some of what I sad can apply. Zoning can be done on steam with thermostats and aquastats, just not as easily depending on the piping. Most likely it is not piped individually.