Contractor needs a double check on EDR

JudySweetland

I have a total EDR of 665 sq ft. The old Crown boiler had an input of 299,000 btuh. Do I now add a 33% or a 50% pick up factor to the 665 sq ft number for the new Crown boiler? (am choosing Crown because of limited basement space for piping, it must be on the left side of the boiler as it is now and Crown seems to be he only man. with this set up) There are NO steam experts in our area (Virginia Beach, Norfolk, Va area) I have already called two "experts" and they say no, don't add anything. However Dan's books say to add a pickup factor. I have read extensively and have Dan's books, Lost Art...., pumping away, and have printed out several Heating Help articles. I want to make sure I am not making a mistake with this customers equipment and how it will affect fuel bills, operation etc after the install. Thank you in advance.

JudySweetland

Crud I mean't the piping is on the right side of the boiler

KC_Jones

Look at the specs on the boiler. They should give sq ft of steam rating for the boiler. That is a direct comparison to the EDR number you have in hand...you do not add anything to this. Most if not all boiler manufacturers add the pick up factor for you. Here is the rating chart for Crown boilers, see the column labeled sq ft.? Go by that number, which would be the BSI276 boiler rated for 708 sq ft. That means the current boiler is probably over sized.
http://www.crownboiler.com/Products/Bermuda_BSI

JudySweetland

KC, thanks for responding. I called Crown this am and talked to BOB in tech services and he said Crown does not add a pick up factor, which is contrary to what I have read in general about manufacturer specs. Can you advise? Thanks

KC_Jones

The chart on their own website clearly shows a pickup factor. I will break down their own numbers. The boiler has a gross input of 276000 BTU multiply that by it's rated efficiency of 82.2% you get their 229k rating in the column labeled "Heating Capacity (MBH)" then you divide that by 1.33 for the pickup factor and you get the net rating of 172 or 708 sq ft as listed on their chart. I don't get those exact numbers, but sometimes they round differently. You get the idea though. I am not sure what they told you maybe they don't understand I am just looking at the numbers on their own ratings chart.

JudySweetland

Dog bless you KC. Thanks. I did not know that is how it is figured.

nicholas bonham-carter

Is there no room above the boiler for pipes coming straight up from the boiler top, like the Peerless? Two risers will always make better steam, especially when piped as a "drop header",into a header, one size larger.
Is this one-pipe or two-pioe steam?--NBC

KC_Jones

Hatterasguy said:

665 square feet X 240 = 159,600 BTU's to heat the building.

A boiler that is 82% efficient would need a gross input rating of 194,600 BTU if it had no pickup factor. The manufacturers, including Crown, add a 33% pickup factor to the boiler to be sure it will do the job after the install. Their eight section boiler has a gross input of 241K but only 149K is considered available to heat the building.

The Crown Bermuda eight section boiler, 241K input, 149K net with the pickup factor is the boiler you want. The boiler offers a slightly smaller pickup factor of 24% versus the recommended 33%. Most of us are in agreement that the 33% is more than required for a properly vented system. Just be very sure of your EDR figures. You don't want to make a mistake by 50 EDR or more if you're selecting a "smaller" boiler.

Remember, larger is not "better". The boiler will cycle on pressure constantly if is is too large for the building.

I don't disagree, but wanted to clarify slightly. Selecting the smaller boiler will definitely require a finer tune on the system than the larger one. I personally would probably go a bit smaller, but that also depends on real world conditions pipe insulation etc. You would most likely be able to get the smaller one working no problem. I was just breaking down the raw numbers, beyond that is up to your experience level as to how you move forward. Most of the "tuning" I am talking about would need done no matter what to get a nice running system. It is harped on many times on this site. These are systems not a boiler with some stuff hooked to it. When you replace a boiler it is good practice to evaluate the entire system, not just replace the boiler. When I did mine I went with the full 33%, BUT in a couple years I am adding square footage and more heating so I allowed some grow room. Also if you go with the 8 section and get it running properly there will be fuel savings over the 9. Either one will show fuel savings over the monster that is currently installed!

KC_Jones

Hatterasguy said:

Well said, KC.

If the system isn't brought up to proper conditions with venting and full insulation, the smaller boiler won't cut it.

The manufacturer never wants to be caught out when the boiler is installed in less than optimal conditions, so he always uses the 33% factor. In some of the pitiful installs that we've recently observed on here, that 33% is absolutely required.

On some of the ones we have seen posted recently, they would have been better off down sizing because the pipe work was so small it couldn't deliver all the BTU's anyway. To the OP are you a contractor doing an install or a homeowner double checking a contractor? If you need any other help feel free to ask.

JudySweetland

Well guys since you asked!.....this is a 2 pipe system. I am going to install 2 risers to a dropped header due to head room (dimensions A & . The near boiler piping right now is not correct. It had a dry and wet return with a Hartford loop. There is no main vent. There is however a F&T trap and a bucket trap installed. There are no obvious thermostatic traps on the radiators so I am hoping they are the ball check valve type on the return side of the radiator. One radiator has a bullet steam vent that is sucking in air. Both the supply and return piping is on the bottom of the radiators. The house was built in 1906 and seems to have the original Rocco American Radiators still in it.
There is a hot water loop off of the boiler for a den with baseboards heat and that seems to be piped in wrong with components from 1991 and apparently it has worked intermittently over the past 4 to 5 years. I haven't figured the correct way to pipe that in yet, but I am reading a lot. The return is not pumped in it is a gravity return. any advice is appreciated. If none is given wish me luck and smart piping. I am still researching all I can on this site. Great site, great advice. I purchased Dan's DVD too and am going to start watching that. Steam heat is really an art and someone like myself has no business getting involved unless properly armed with as much info as possible and due diligence! Crickey how did you guys learn all this stuff?

ChrisJ

I'm a big believer in little (10-15%) or no pickup factor. But to do so the system must be setup correctly and you must be accurate on your EDR measurements. Pipe insulation is an absolute must as well. I would never recommend going over 33%.

@Hatteraguy, What were the reasons a 33% increase in size was an absolute requirement? Bad piping, no insulation?

JudySweetland

I am a Contractor and here in Norfolk Va we have a lot of HW Boilers but VERY few steam systems left. This customer loves the steam heat and wants to keep it I agree. I have a feeling a quite a number of steam systems were converted due to mistakes made and prob. people working on them that did not know enough to address the problems. Geezus i hope I am not one of them!! BTW right now there is one 2" riser with an equalizer piped into the return, Hartford loop. The 2" riser is piped into a 2" header. I plan to use two 2" risers and change the header to a 3". Should I still add a main vent to the dry return close to the boiler since there is a F&T and a bucket trap installed. I am wondering if this had a pumped return at some point but the owner does not know. Any thoughts on the venting for a 2 pipe system?

ChrisJ

Is 2" the largest the boiler's tapping will allow? For that size boiler it would be nice to see two 2.5" or 3" risers into a 4" header.

I have zero experience in regards to venting a two pipe system so I cannot comment.

I doubt you're going to be "one of those guys" because you have already gone much further than many by researching what you're doing before hand.

If you want attach a drawing of the piping you want to do and we can make sure it's good before you order the parts etc.

ChrisJ

Hatterasguy said:

ChrisJ said:

@Hatteraguy, What were the reasons a 33% increase in size was an absolute requirement? Bad piping, no insulation?

I'm simply theorizing on why all manufacturers use 33%.

If the install is done under less than optimal condition and there is no insulation with questionable piping and venting, the manufacturer would never want to be caught with a boiler that is "too small" and cannot heat the building. So, they all use 33% which covers them under the worst possible situations.

I agree with you in that the 33% figure is ridiculously large for most installs.

Ah,
I don't have it handy but Gerry Gill posted an article that was written in the 1950s that explains the 33% "Piping and pickup factor" and it was mainly in regards to being able to rapidly do a recovery in a cold building. 33% was basically the happy medium between slow recovery and using too much fuel but I think we were also talking radiation that was not oversized and buildings that were ice cold, like a school during winter shut down.

The fact we tell most not to do setbacks with steam combined with the fact most homes have way too much radiation to begin with makes the 33% unnecessary in my opinion.

KC_Jones

ChrisJ said:

Is 2" the largest the boiler's tapping will allow? For that size boiler it would be nice to see two 2.5" or 3" risers into a 4" header.

I have zero experience in regards to venting a two pipe system so I cannot comment.

I doubt you're going to be "one of those guys" because you have already gone much further than many by researching what you're doing before hand.

If you want attach a drawing of the piping you want to do and we can make sure it's good before you order the parts etc.

I agree Chris, but those boilers only have 2" tappings so that's about as good as it gets. The 3" header is a good match to those tappings, but I think a bigger header size would help slow things down even further, but would be nice to hear from someone more experienced to make sure. The planned drop header is a fantastic idea!

JudySweetland

Now I will go with the 2.5 or 3" risers into a 4" header. Seems like the majority have experience here and I will adjust the piping to fit the best or ultimate way of doing this. I do understand about the height for the risers. I am still a bit confused about the venting requirements given i don't know if the return els on the radiators have the ball check in them. Would it hurt to add a main vent on the return close to the boiler? Should I add a main vent on the steam header somewhere? This piping goes around in a square in the basement. I have approx. (not measured exactly yet) 70' of main steam pipe and the equivalent of return piping. ALL of it will be insulated. I do not know how the piping makes it up to the 2nd and 3rd floors, as this piping is hidden in the walls.

nicholas bonham-carter

If one of the vents is sucking air, then you must have a vacuum system, also known a "sub-atmospheric". You might do a search here on the vacuum subject. Steam can travel very quickly in a vacuum!--NBC

ChrisJ

Hatterasguy said:

ChrisJ said:

The fact we tell most not to do setbacks with steam combined with the fact most homes have way too much radiation to begin with makes the 33% unnecessary in my opinion.

I'll give you another take on the pickup factor.

My system has an EDR of 605. The input is 262K on high fire. Equals a pickup factor of 48%. Should be grossly oversized on high fire.

But, it isn't.

It runs for 45 minutes continuous and only develops 3 ounces on high fire.

Now, I could have made a gross error on the EDR, but I don't think so. It was done very carefully, radiator by radiator and I am positive that I didn't miss any of them.

KC has a similar situation. He's got the 33% pickup factor and he doesn't develop any pressure either. Cannot ever get to low fire.

So, something is affecting the results regarding pressure in both these system, which are admittedly done to perfection regarding piping, headers, and insulation.

I did 33% as well and only run 0.5" WC 90% of the time. I tripped @ 1.5 PSI years ago after running for 1 hour 20 minutes.

My guess is I calculated my EDR wrong but in the end it doesn't matter. The system can only condense so much at a given temperature and fact is we do not heat all of the piping and all of the radiation up at once. First we heat our insulated piping, and then we slowly heat our radiation. When vented correctly the system should run fine even if the boiler is 50% undersized, though we may not be able to heat the structure.

I'm using an EG-45 and even though it runs @ 0.5" most of the time if I had to do over, I'd probably go with an EG-40 knowing what I do now.

JudySweetland

nicholas bonham-carter said:

If one of the vents is sucking air, then you must have a vacuum system, also known a "sub-atmospheric". You might do a search here on the vacuum subject. Steam can travel very quickly in a vacuum!--NBC

Ok will do a search.

KC_Jones

Part of my problem is no insulation so I am making condensate at an alarming rate. Need my tax returns for the insulation...come on 2015! You say it's a 2 pipe with no traps at the radiators, isn't the other possibility is an orifice system? I have zero experience with that. To the OP you may want to start a new thread for advice on that aspect of tuning a 2 pipe system and/or getting input on it. There are a lot of very experienced people. In addition pictures are a very good thing. Pictures of equipment installed and the traps etc. Help you identify the system.

JudySweetland

KC_Jones said:

Hatterasguy said:

ChrisJ said:

KC has a similar situation. He's got the 33% pickup factor and he doesn't develop any pressure either. Cannot ever get to low fire.

Part of my problem is no insulation so I am making condensate at an alarming rate. Need my tax returns for the insulation...come on 2015! You say it's a 2 pipe with no traps at the radiators, isn't the other possibility is an orifice system? I have zero experience with that. To the OP you may want to start a new thread for advice on that aspect of tuning a 2 pipe system and/or getting input on it. There are a lot of very experienced people. In addition pictures are a very good thing. Pictures of equipment installed and the traps etc. Help you identify the system.

I will be posting pics, I am going to remove the existing insulation so a clear pic of the piping is available, I will also post a drawing of what I intend to do. Really appreciate the help I have been given.

ChrisJ

Hatterasguy said:

ChrisJ said:

I did 33% as well and only run 0.5" WC 90% of the time. I tripped @ 1.5 PSI years ago after running for 1 hour 20 minutes.

My guess is I calculated my EDR wrong but in the end it doesn't matter. The system can only condense so much at a given temperature and fact is we do not heat all of the piping and all of the radiation up at once. First we heat our insulated piping, and then we slowly heat our radiation. When vented correctly the system should run fine even if the boiler is 50% undersized, though we may not be able to heat the structure.

I'm using an EG-45 and even though it runs @ 0.5" most of the time if I had to do over, I'd probably go with an EG-40 knowing what I do now.

That would mean that all three of us calculated the EDR wrong..............unlikely. There must be another variable.

I can tell you, with certainty, that the system will not heat all the radiators on low fire (157K input). I found it on low fire on Saturday due the boiler going crazy for a desperate need for a skim. It built 10 ounces in the boiler on low fire with the waterline fluctuating wildly.

The building was COLD. None of the radiators at the ends of the mains would heat at all. The ones that did heat would not heat all the way.

So, you can undersize them. The 157K input represents a negative pickup factor of 10%. I'm fairy sure it could not perform with a pickup factor of 0.

What is the reason you could not heat the building with 10oz?
What is your longest amount of piping including the main and runout to the radiator (total distance from boiler to radiator)?


I do not consider a system with a very dirty boiler as being a valid test. Dry steam is a must.

ChrisJ

Hatterasguy said:

ChrisJ said:

What is the reason you could not heat the building with 10oz?
What is your longest amount of piping including the main and runout to the radiator (total distance from boiler to radiator)?


I do not consider a system with a very dirty boiler as being a valid test. Dry steam is a must.

I could not heat the building because it was running on low fire. Not enough steam despite the fact that it was hovering around 10 ounces.

The total distance from the boiler to the last radiators is about 80 feet.

It only shows what the system will do on low fire. Are you thinking the steam ended up wet due to the surge (7-8 inches on the glass)?

Yes, wet steam.
I cannot see any reason 10 ounces wouldn't heat a radiator on an 80' run. Typically steam pipes are sized for 1oz drop per 100ft if memory serves. As I said, I heat everything @ 0.5" WC which is around 0.28 ounces. You had 36 times that pressure.

ChrisJ

Experimenting is always good.

vaporvac

That is most likely an older two-pipe vapor system given that both the supply and return are on the bottom.. Dan talks about it in the lit section. I'll try and find the exact discussion when I'm home. Pictures of the boiler/basement piping would help as it would be a shame to do something to destroy the integrity of the system itself. Many vacuum systems were destroyed which, as the owner of one, was a shame.
Any vents on the rads need to be plugged.

JudySweetland

vaporvac said:

That is most likely an older two-pipe vapor system given that both the supply and return are on the bottom.. Dan talks about it in the lit section. I'll try and find the exact discussion when I'm home. Pictures of the boiler/basement piping would help as it would be a shame to do something to destroy the integrity of the system itself. Many vacuum systems were destroyed which, as the owner of one, was a shame.
Any vents on the rads need to be plugged.

Ok that is helpful. I went to the job site today and removed the insulation from the near boiler piping. I did find a vacuum breaker on line that is located in a 1" pipe going from a steam riser. The VB is located after a Hoffman 1140 temp control assembly but just before a B & G braze plate heat exchanger, the pipe containing both the Hoffman 1140 and the VB goes into the HOT IN port on the ht exchanger. I might add the VB was encased in the insulation, had no idea it was there until i removed the insulation. Any reason someone would TOTALLY enclose a VB in insulation? Thanks. I will be posting pics when i get home this eve.

JudySweetland

Here are some pics. Not much room in the basement. This is in reference to a two pipe system i posted questions about earlier today. Not sure how to use this thread well. Thanks.

KC_Jones

Not much room? lol I have 70" to the bottom of my joists your situation looks incredibly massive to me!

KC_Jones

I agree with Hatteras I would look at other boilers an not necessarily shoehorn your self into another Crown. I was looking again and keep in mind the new boiler doesn't have the side tappings like that on. The new ones have take offs on top like a lot of other manufacturers. Those 2" would be fine for a lot of applications, but the size you are installing I would look into something with 2.5 or 3" tappings. Just my opinion.

vaporvac

I used very little space for my two SF TR50s in order to make it work. I'm really most familiar with my old boiler (Dunkirk) and the wet-based ones i considered as replacements. They are small than atmospherics albeit heavier. Have you considered going that route with a conversion gas burner? It might give you some more space among other things.

JudySweetland

The pics are deceiving. There is a hwh to the left of the boiler and an electrical panel. The entire hwh heating circuit that is on the right would have to be repiped. There are plumbing pipes on the left that are in the way too.
I have exactly 31.5 " from the new boiler water line to the highest header point possible. Doesn't seem like much room to me. There is also a section of the dry return that has 3 feeds to it i would also have to repipe completely. The idea is to use the space avail. And to do it correctly. I have 23" to the left of the boiler before hitting the DHWH, and 44" on the right. I would rather figure this out piped from the right side as it is without reinventing the wheel only to find it rolled me to the same place i would have been had i piped in from the right side to begin with, avoiding cast sewer mains, cold water plumbing, kitchen sink drain and moving the DHWH. So....... now what? (The new Crown boiler piping comes off the top of the unit). The vacuum breaker is a concern and the venting for a 2 pipe system as well.

ChrisJ

Are you doing a drop header?

A drop header can be almost touching the top of the boiler as long as the risers go up 24-30" above the top of the boiler first. With a drop header, it's the height of the risers that count, not the header as long as it's not below the top of the boiler..

JudySweetland

KC_Jones said:

I agree with Hatteras I would look at other boilers an not necessarily shoehorn your self into another Crown. I was looking again and keep in mind the new boiler doesn't have the side tappings like that on. The new ones have take offs on top like a lot of other manufacturers. Those 2" would be fine for a lot of applications, but the size you are installing I would look into something with 2.5 or 3" tappings. Just my opinion.

I will look at other boilers, i have not committed to the Crown, and i could move the gas DHWH 14" to the left just by the EP and repipe it all. Do you think it will make a big difference. I was going to install an increaser on the boiler taps from 2" to 3" right out if the starting gate......unless that will not make an improvement overall. I only chose the Crown based on boiler connections and EDR. THANKS.

JudySweetland

ChrisJ said:

Are you doing a drop header?

A drop header can be almost touching the top of the boiler as long as the risers go up 24-30" above the top of the boiler first. With a drop header, it's the height of the risers that count, not the header as long as it's not below the top of the boiler..

Yes i had planned a dropped header. But am reading all the posts and some think i should consider a different boiler altogether due to the 2" boiler connections being too small.
What are your thoughts?

JudySweetland

Hatterasguy said:

The Peerless 63-05 is only 24 5/8" width as compared to the 29" on the Crown.

Ok, i will have a look.

vaporvac

Regarding my prior post on your type of system... I think this is what DaH talks about in this article: https://heatinghelp.com/systems-help-center/a-steam-heating-primer/

Scroll down to two-pipe steam. I believe it is called a two-pipe air-vent system. There are some other articles and posts on this if you search. Perhaps this might point you in the right direction. If not, when some of the pros aren't quite so busy, they might have a chance to comment on the correct venting. I'm having a hard time viewing the pice upside-down.

KC_Jones

Is this system zoned? How many mains are you dealing with? The pics are a bit confusing with so many pipes. It appears all the return pipes are tied together above the water line...I know on one pipe that is a no no, but not sure about 2 pipe?

JudySweetland

This is a tough decision for me, the piping space and the extra work involved in comparison to the potential benefits if any. I am not experienced in steam piping, but industrial, commercial and residential gas piping i am experienced in....... Cutting and trying to thread3" pipe between joists sounds like trouble. When u guys repipe/ redesign the piping do you start over.....cut back to the most practical place and start over?

JudySweetland

vaporvac said:

Regarding my prior post on your type of system... I think this is what DaH talks about in this article: https://heatinghelp.com/systems-help-center/a-steam-heating-primer/

Scroll down to two-pipe steam. I believe it is called a two-pipe air-vent system. There are some other articles and posts on this if you search. Perhaps this might point you in the right direction. If not, when some of the pros aren't quite so busy, they might have a chance to comment on the correct venting. I'm having a hard time viewing the pice upside-down.

I'll have a look and thanks for the info.

ChrisJ

JudySweetland said:

ChrisJ said:

Are you doing a drop header?

A drop header can be almost touching the top of the boiler as long as the risers go up 24-30" above the top of the boiler first. With a drop header, it's the height of the risers that count, not the header as long as it's not below the top of the boiler..

Yes i had planned a dropped header. But am reading all the posts and some think i should consider a different boiler altogether due to the 2" boiler connections being too small.
What are your thoughts?

One of the reasons I went with a Weil-Mclain was it has 3 inch tappings.

I ended up only doing 2" risers due to cost, but my boiler is only 150K input. For this size 3" would be perfect into a 4" drop header.

JudySweetland

KC_Jones said:

Is this system zoned? How many mains are you dealing with? The pics are a bit confusing with so many pipes. It appears all the return pipes are tied together above the water line...I know on one pipe that is a no no, but not sure about 2 pipe?

On a call for steam heat an actuator lifts up and allows steam to the mains. There are 2 steam mains and one reduced main going to a honeywell 1140 thermo valve for the baseboard HW circuit. There is a ton of pipes around the boiler, some are domestic hot and cold water pioes, sewer piping, waste drains blah, blah, woof, woof. It us tight all over above the boiler. It would be great if i could repipe everything in the basement, but that is a pipe dream..