Heat Loss Calculation Not Needed

October Home

After being in business for almost 20 years I got a job at my local municipality. I like it. I'm happy. I started in February. My municipality has grant funds for repairs on homes for low to moderate income home owners.

So. I have a chance to replace a boiler. Gravity fed, natural gas. I re-read the first chapter of "How Come?" and then tried to get a heat loss calculation done.

Nope.

You'd have thought I had sprouted another head the way one contractor looked at me. He confidently told that it's not necessary.

Another contractor told me that a modulating boiler makes a heat loss calculation unnecessary because a modulating boiler knows how many BTUs the house needs at any point in time.

Is the first chapter in "How Come?" still valid?
Is this 2006 thread still valid?
https://forum.heatinghelp.com/discussion/112286/replacing-gravity-heat-boiler
Is this article (2016) still valid?
https://www.greenbuildingadvisor.com/article/sizing-a-modulating-condensing-boiler

Thanks for your help,

Arlene

Danny Scully

I’m going to answer your question by not answering any of your direct questions...you need to find another contractor. Heat loss calculations (of some kind) are always necessary.

Mike_Sheppard

It still applies. Find another contractor.

Alan (California Radiant) Forbes

Hey there, Arlene:
Keep searching for another contractor.
What part of the country do you live in? Maybe we can help you find someone.

Steamhead

What @Danny Scully , @Mike_Sheppard and @Alan (California Radiant) Forbes said. Are you still in NY State?

October Home

Thank you all!
Maybe I'll just do it myself.
Yes, Steamhead. In the Hudson Valley. Between Albany and Manhattan. Looked on this website, nearest contractor too far.

EBEBRATT-Ed

@October Home
Slant Fin has a program you can download. Fairly simple and it does a good job.

A heat loss should always bee done with every system except steam. With steam you calculate the existing radiation load and use hat value to size the boiler

gennady

EBEBRATT-Ed said:

@October Home


A heat loss should always bee done with every system except steam. With steam you calculate the existing radiation load and use hat value to size the boiler

What about scenario: all existing steam radiators 10x oversized?
Heat loss on steam system still needed. Even more, room by room heat loss and edr must be compared. During renovations radiators could be swapped, so large radiators are installed in small rooms and small radiators get installed in large rooms. Sometimes new partitions installed during renovations, leaving rooms with no radiators. I had seen buildings with all new undersized radiators installed.

HVACNUT

> @gennady said:
> @October Home
>
>
> A heat loss should always bee done with every system except steam. With steam you calculate the existing radiation load and use hat value to size the boiler
>
> What about scenario: all existing steam radiators 10x oversized?
> Heat loss on steam system still needed. Even more, room by room heat loss and edr must be compared. During renovations radiators could be swapped, so large radiators are installed in small rooms and small radiators get installed in large rooms. Sometimes new partitions installed during renovations, leaving rooms with no radiators. I had seen buildings with all new undersized radiators installed.

Steam doesn't care about anything but itself. It only knows it wants to get to the last radiator without first condensing. That's where the pros (I'm not saying you're not) come in, with controls and vents and such to make sure the steam gets there.