Sizing new boiler

kevin coppinger_4

up...you can't ever properly size a new boiler from the old one...If its steam you need to measure all of the rads and find out trhe amount of sq. ft. of steam needed to get the system hot. AKA-measure the connected load. Then you can size the boiler. Length x width x # of sections...what are the contactors qualifications w/ steam? Done a bunch or just a few...references...

jim_14

based on this picture and assuming

it was the right size when it was first installed 50 years ago what size boiler would you replace this with?

Ive gotten boiler estimates from 112,000 BTU to 150,000 btu with seperate 50 gal HWH

One estimate I got was for 155,000 BTU boiler with tankless heater and seperate indirect 40 gallon hot water heater.

Curios to know what you guys think...

BTW its gas 1 pipe steam and gas HWH

jim_14

Ive done a bunch of references

Some are plumbing/heating companies, others just advertise as "heating" contractors.

Some asked how many rads in house.

Some of the estimates came from people who have over 30 years in the business. Its hard to "argue" with someone who's been doing boiler installs his whole life.

Just about every guy who's come into my home as told me to stick with a 50 gal HWH and not go with the seperate indirect. Only one guy didnt try to talk me out of it and gave me a proposal with the indirect tank. Much higher estimate, but I understand the indirects cost more and the boilers with the DHW coils cost more too.

kevin coppinger_4

that's great...

but...did they measure EACH rad..not just how many. If you don't you/they are just guessing...and probably oversize the boiler ,ie. higher heat bills... The separate water heater is probably fine...do you run out of hot water now? Indirects are great and if you need the hot water, a good choice. You can use them on a steam system it just takes a bit more to do it right compared to a hot water boiler. When the current water heater fails you could consider changing it then.
What's more important that the steam boiler is sized right & piped right...I know others will agree...kpc

jim_14

nobody has ever measured each radiator or looked past

the basement, and I mean NOBODY!

The only thing I can say in their defense is that I live in an urban area, theres alot of houses built like mine (same size, similar layout, maybe same builder) so that some of these people who've been in the business 30 years have seen this before and worked in houses just like mine. Im guessing if they mis-sized a boiler it was long ago. Again,Im just guessing..

It may well be that they get a lot of calls this time a year from people fishing prices for a new boiler but then balk when they realize how much it would cost. If they took the time to size everything on every estimate it would be a waste of their time and money...

Keep in mind the BTU sized boilers include a basement hot water zone.

One guy pointed out that insulating my steam riser wasnt even worth the money spent on the insulation since what I would save amounted to pennies each year (based on my small house and 25 foot steam riser that runs from the boiler to back of house). And this guy had 30+ years in the business.

Now I know better, cause Ive read The Lost Art, and I told him I insulated because the basement became just too hot for comfort every winter with pipes uninsulated.

Now I didnt want to argue with a 30 year pro over insulation and the effects of condensation and the pipe acting like a long radiator, etc etc so I let it be. I mean how does a homeowner tell a guy like that "how heating works"?? I feel like they would think to themselves "if he knows so much then why I am here?"

Do you know what I mean?

Mark Eatherton1

I know what you mean...

Many of my steam customers have Dans TLAOSH book and they know 10 times more than their service contractors do. Pretty scary eh...

ME

kevin coppinger_4

let me ask...

have you tried the "find a contractor" feature ?...kpc

Boilerpro_3

However,

I've met many customers that understand their system better than many of the contractors I've met.


On another subject, I recently looked at a 4 year old install by a contractor that's been doing steam for years. The first thing I saw was a Weil Mclain EG steamer with both tappings used with no offset header and one supply coming off between the boiler risers and the other after. It also looked awfully big for the home so I asked whether the contractor had walked through the home and measured the rads to size the boiler. Not! I measured everything up and ended up with about a 500 edr load on a 750 edr boiler. The installing contractor returned and when the homeowner told him how I checked the boiler size he just shook his head.

It really is difficult going up against guys that have been in business 4 times longer and apparently all that time had not sized steamers right or installed them incorrectly.

Sigh,

Boilerpro

jim_14

Yeah what do you say to a guy

whos been doing that for years? Even worked on your block ,in your neighbors homes....

So how would I size my boiler correctly?

jim_14

Yes

Nobody close to me

Irene_2

old timers

Being in the business 30 years doesn't automatically mean they know a damn thing. It simply means they think they do. I just had my boiler, mains and returns replaced by a company who offered to come and take a look after reading my SOS posted on the wall. And they did a fabulous job. Thanks again to the guys from Gateway. They came out and did a complete heat loss and presented me with a well laid out proposal. Previous to that I had someone else from the "find a contractor" feature who came out, walked through my house talking on his phone non-stop, "been the business 30 years", didn't have to look hard... Wasted my time and money. I recommend that all homeowners learn as much as they can, read Dan's book and read all the posts on the wall. You will learn very quickly how to tell who knows what they are doing.
Thank you to all the people on the wall who contributed to my education and enabled me to have a wonderfully quiet, working steam system....
Irene

Unknown

I'll help you, Jim.

Do you know how to measure up the radiators yet?

Noel

Fred P

No, I dont know how to measure

the rads as far as determining what the proper boiler size should be

Unknown

OK, here goes.

We start with a single section, of which several together make a radiator. A single section has a height, a depth (or width), and a number of tubes, or columns, or risers, or pipes, or whatever you like to call them.

You need the number of columns in one section,

the height from the floor,

the front to back width of a section,

and the total number of sections.

From that, we can identify what the radiator is and it's output from it's square feet EDR rating.

We then add them all together and read the steam sq ft rating on the boiler to see if it is the same or a little bigger.

Noel

Fred P

Im not sure what you mean exactly,

> We start with a single section, of which several

> together make a radiator. A single section has a

> height, a depth (or width), and a number of

> tubes, or columns, or risers, or pipes, or

> whatever you like to call them.

>

> You need the

> number of columns in one section,

>

> the height

> from the floor,

>

> the front to back width of a

> section,

>

> and the total number of

> sections.

>

> From that, we can identify what the

> radiator is and it's output from it's square feet

> EDR rating.

>

> We then add them all together and

> read the steam sq ft rating on the boiler to see

> if it is the same or a little bigger.

>

> Noel

Fred P

Im not sure what you mean exactly,

My rads are not the free standing ones like my grandmother used to have!

Actually they are in the wall with a cover that fits over them. When I remove the cover I see a length of pitched pipe that has little "fins" over them like you see with hot water baseboard systems. The actual word to describe them is escaping me for the moment...

In any case on one end is the valve the other the vent. Do you want me to mesasure the length of this pipe only? It really doesnt have a "height" since its not attached to the floor.

The radiator cover is larger than the actual radiator pipe, do I need to count the # of fins?

Unknown

Convectors...

In that case, measure the height of the cabinet, the width, and the depth of it.

Measure the length, width, and thickness of the finned element. I have some books to look them up in.

Noel