Typical quantity of steam traps

stanleysteamer

I know it is impossible to generalize, but are there any rules of thumb for estimating the average number of steam traps in a typical multifamily building and/or commercial building? Can I get a rough estimate based on the heated area of the building? or on the number of units? or some other metric?

Rod

Count Steam Traps

Not quite sure what you are trying to accomplish. You generally would have to have some sort of physical access the determine what the type and condition of steam system the building contained and if you have physical access then the obvious thing to do is to count the number of steam traps.  I guess if you could get a accurate sampling of the several of the typical units the building contained then you could multiply that by the number of these units in the building though you would still be better off doing an actual physical count. Even then if you were doing something like rebuilding the steam traps it may not be necessary to rebuild them all. Again maybe if you can tell us why you need this information we can tell you how to go about it.

- Rod

Jamie Hall

Couldn't even come close

without knowing the type of system.  Single pipe steam often has no traps at all.  Two pipe steam usually has a trap on every radiator -- and a few others hanging around here and there.  Some vapour systems have only a few traps if any.

stanleysteamer

rough estimate only

I realize that the only way to be accurate for any particular building is to physically inspect that particular building to inventory the traps. What I am looking to develop is some rough estimate for a 'typical' building to give an idea of the size of the problem/opportunity before having a chance to visit the building.



Each building is clearly unique, but if you look at enough of them with similar characteristics, I would think you should be able to develop some approximation that is within perhaps +/-25%(?)



More specifically, for a 'typical' 50,000 sf multifamily building in NYC with two-pipe, low pressure steam and cast iron radiators, can I approximate the total number of traps in the building? Generalizing this further, can I make this same estimate for other buildings based on either sf or no. of units, etc?



I do not have much experience with steam systems, but based on the general design practices that would have been used, I would expect that I could estimate perhaps one trap for each exterior room in the units, and perhaps x traps per sf in the basement. If this estimate got me within +/-25% or so, I could give my customer an idea of the potential for energy savings (rough estimate) by better managing the traps.



I know we all like to do things as accurately as possible, and an estimate such as this is certainly not accurate, so I appreciate a best guess from the heatinghelp experts.

stanleysteamer

rough estimate only

I realize that the only way to be accurate for any particular building is to physically inspect that particular building to inventory the traps. What I am looking to develop is some rough estimate for a 'typical' building to give an idea of the size of the problem/opportunity before having a chance to visit the building.



Each building is clearly unique, but if you look at enough of them with similar characteristics, I would think you should be able to develop some approximation that is within perhaps +/-25%(?)



More specifically, for a 'typical' 50,000 sf multifamily building in NYC with two-pipe, low pressure steam and cast iron radiators, can I approximate the total number of traps in the building? Generalizing this further, can I make this same estimate for other buildings based on either sf or no. of units, etc?



I do not have much experience with steam systems, but based on the general design practices that would have been used, I would expect that I could estimate perhaps one trap for each exterior room in the units, and perhaps x traps per sf in the basement. If this estimate got me within +/-25% or so, I could give my customer an idea of the potential for energy savings (rough estimate) by better managing the traps.



I know we all like to do things as accurately as possible, and an estimate such as this is certainly not accurate, so I appreciate a best guess from the heatinghelp experts.

Dave in QCA

taking a stab at it....

For multi-family residential units, assuming that you have 2-pipe steam with traps, you might come close in estimating the total number of traps by knowing the total number of rooms per unit, and the total number of units.  If you have a building that has 20 6-room units, you're probably going to have 120 radiators each with a trap.  If you add 20% to cover public / common spaces I would think you would have it covered.  Plus, you're might have crossover traps on the mains and possibly F&T traps, depending on how the piping was configured.

For other commercial buildings... it all depends on whether there are a lot of small rooms, such as an office building, or whether it has few, but very large rooms, such as in a loft type building where very large industrial spaces are converted to another use.  In the second case, the building would probably have a lesser quantity of large radiators, and in the office type building, there would likely be a large quantity of smaller radiators. It all depends on the building and how it was designed.

stanleysteamer

Thanks Dave

That is exactly the kind of estimating method I am looking for. It will certainly not be accurate, but it is at least a "reasonable guess" to get me started.



Thanks

Rod

Estimating Steam Traps

Hi- I agree with Jamie. Further more I would think if you approached a  customer who has a basic knowledge of steam heating and used such an approach you would lose your credibility. Individual building steam systems are too unique and quirky to use an approach like you propose.  It's sort of like going up to someone and saying, "I can fix your car for $200 !"  The customer then thinks..."You haven't even seen my car or know what make and model it is, so making such a statement shows you really don't know what you're doing!"  I'm not trying to discourage you, I just think you would do better by changing your approach.

As to NYC buildings and steam traps-  the following might be of interest to you.

You might want to Goggle using the words - Henry Gifford orifices     That should take you to his webpage. Scroll down the webpage to the Technical section and look under Two Pipe Steam Systems. Find a link on "orifices". There is an interesting article there that might be of help to you.

- Rod

Dave in QCA

Caution !!!

I have to say that I too am in complete agreement with Jamie and Rod, in spite of my suggestions on guessing how many traps might be in a building.  My comments regarding estimating how many traps might be in a building are intended for the purposes of preparation, before you actually go into the building, so that you might have come kind of idea what you are looking for and what to expect.  If you are putting together an estimate for trap repairs in a building, it is important that you do NOT use any hypothetical means of estimating how many traps might be in a building.  There is not such thing as an average or typical building. 

stanleysteamer

orifices

Thanks for the caution, and the interesting link.

stanleysteamer

understood

Thanks for that caution. I think I am on the same page with regards to the usefulness of an estimate. I certainly wouldn't generate a definitive savings estimate or job quote based on this, but it helps to put an order of magnitude on the subject for my own internal processes.