Excel Heating Calc Program jpf321

Maine Vent

I have a 2" main about 35' long. On the recommendations page the values for 1,2 or 3oz do not change when I make changes to any of the values on the worksheet page under the Main Rad. I have tried many different values to see if the recommendations change for the Main Rad Type. I am trying to see how many vents I will need for a long main and a main. Any advice is greatly appreciated. 

Maine Vent

I updated program

I figured this out, I downloaded your new version. Works much better.

Thank You

jpf321

sorry I missed this earlier

everything ok now?

Maine Vent

New Excel question jpf321

1. I have long main of 35' X 2" dia, and a short main of 4' X 2". How do I figure the sq ft EDR of these pipes for the main vent recommendations?

2. I have the Balance your system pdf from Gerry, I understand the time to vent for the main vent times. As I work the spreadsheet with the time to vent for the radiators each time I make a change to the time variable it changes the rad vent recommendation. Here is the question, how do time the vent time to each separate radiator. Example, start of boiler to a hot rad. valve, or when main vent gets hot then time to each rad. valve, or do I pull the rad. vents and time to full heated radiator? Thanks for photos and all your research into steam heat.

jpf321

minutes to vent is SUBJECTIVE

1) you don't enter the EDR for the mains .. you can leave it be 0 .. you only need TYPE=Main, Length and Size (in nominal IPS pipe size) .. not sure how to exactly get the sheet to tell you the correct answer if your steam main reduces in size during it's length .. but if that is the case with yours, let us know and we can get you the proper value. (As an aside, but not to confuse you .. EDR of 1linear ft of 2.5" pipe =~ 1 but this is NOT needed for the sheet, but it may help you someday)



2) minutes to vent is not a TIMED value .. but rather a subjective value which you set as the homeowner .. it is also quite theoretical. I read recently that most of the time lag for steam filling iron is actually the delay of bringing the iron up to temp .. called steam creep .. rather than the actual movement of the steam .. once all pipes are to temp, steam moves fast .. but cold pipes causes steam creep.



anyhow .. again, the mins to vent is theoretical and as per your wishes .. this is not something that you time and then enter into the sheet. it is the only value in the sheet that is completely at your whim. I've heard that several people like to start at around 3-5mins .. again, this is theoretical assuming pipes are 100% at steam temp.



hope this helps .. i'm happy to have other weigh in.