Security Seal Facebook Twitter GooglePlus Pinterest Newsletter Sign-up

One homeowner’s tale


Dan Holohan
February 3, 2009
Subscribe to RSS feed

I tell you this tale because when products are not properly sized they usually become product problems, and your problems, even though neither the product nor you are to blame.

            There was this old steam boiler, but a dozen contractors visited the homeowner as he looked into having it replaced. That’s what he said – a dozen contractors. He may have been exaggerating, but even if it was a half-dozen, I still think that’s a lot. Don’t you? I mean how many people would you invite to quote on a big-ticket item such as a steam boiler. If you weren’t in the business, that is.

            Would you call three? I think I’d call three. Most people would. But suppose all three contractors showed up, looked around, and then came up with a different size for that replacement boiler? And here I’m not talking about slightly different; I’m talking wildly different.

            If that happened to you, would you call a fourth guy, just to be sure? Would you figure that if two of the four were close in their sizing, then that must be the correct size? Sound good to you? But what if the fourth guy came up with a different number from the other three guys? Would you call a fifth guy? And a sixth? And what if a dozen contractors each came up with a different size for that boiler?

            That’s what happened here. One guy looks at the old boiler’s label and quotes a new boiler, based on the size of the old boiler, even though things in the house have changed over the years. Another guy does a rule-of-thumb heat loss of the house, figuring so many Btus per square foot of floor space. He says he’s been doing it this way for years.

            A few of the contractors measure the radiators, which is the right way to go when it comes to replacing a steam boiler, but they each come up with a different-sized boiler for the same radiation load.

            The homeowner stands back and watches all of this, and he wonders what to do. And then he does what most people do these nowadays. He does some internet research. And if you’re like me, this will probably nag at you. I think that when a homeowner calls a so-called heating professional for a new boiler, that pro should be fully confident, compelling, and thoroughly capable of explaining all the whys of what he’s proposing. Once he’s spoken, the homeowner should nod his head and feel comfortable. That’s what I think.
            But that’s often not the case, especially when it comes to the old stuff, and that’s really a shame. I don’t think professionals should send homeowners running to the internet, but this homeowner was getting a dozen different opinions, so he what was he to do?

            He found his way to and sent me an email. He told me about his radiators, and how they all had enclosures around them. He learned from lurking on our bulletin board, and by reading the technical sections of the site, that a steam boiler’s ability to produce steam has to match the system’s ability to condense steam. If the boiler is too large, it will short-cycle and waste fuel. If it’s too small, it will run for a long time, heat the house unevenly, and waste fuel. You have to size it right to make it work, and to do that, you have to carefully measure the radiators and look closely at the piping.

            Once he learned this, and since all the contractors were coming up with different sizes for the radiators, the homeowner bought a book that shows the true ratings of old radiators. He measured for himself and the boiler size he came up with was much smaller than what any of the contractors were proposing. This made him nervous, and that’s why he emailed me. What did I think about all of this?

            I asked him a few questions and he told me that most of the contractors were very concerned with the enclosures around the radiators. They told the homeowner that enclosures cut down on the heat, and that they would have to figure that into the size of the boiler. This may or may not be true. It all depends on the type of enclosure. Some enclosures actually increase a radiator’s output by creating a chimney effect for the air as it warms itself on the hot metal and rises. There are charts that show this effect and they’re easy to find on the internet, but they can be confusing.

            For instance, the chart I’m looking at right now shows a freestanding, cast-iron radiator with a simple shelf over its top. The caption under that drawing reads, “Add 20%.” What that means is that if you want that radiator to put out the same amount of heat as it would if shelf were not there, you would have to increase the size of the radiator by 20 percent.

            And look at this other radiator. It has a different sort of enclosure, the kind you’ll see all the time in old houses. This enclosure has a solid, hinged top, and a metal front grill with about a million tiny holes. It’s a classic. The chart tells me that I would have to add 30 percent to the size of that enclosed radiator to get the same amount of heat that I would get from an unenclosed radiator. 

            But all of this concerns the person installing the radiators, and that person is currently dead. He did a heat loss on the house back in the day, figured on using enclosures so the children wouldn’t catch on fire, and then sized the radiators accordingly. He would have added the extra square footage of EDR to the radiator back then to compensate for what the enclosure was blocking in the way of convection. His work is done and he has gone on to his reward.

            The trouble here is that the contractors who are currently alive and visiting this homeowner are adding 30 percent to the size of the boiler they’re proposing, and all because of the radiator enclosures. That’s going to give them a boiler that’s far larger than the actual connected load, and that boiler will short-cycle and waste fuel.

            When the homeowner got educated about all this, some of the contractors argued with him. What the heck did he know? He’s a mere homeowner. They’ve been doing it this way for years. They’re not going to take orders from this jerk.

            I asked the homeowner if the rooms have been warm up to this point, and he said they have. That’s a good question to ask, don’t you think? His answer told me that the radiators were the right size for the rooms they were in, even though they were inside enclosures. So what would be the point of increasing the new boiler’s size by 30 percent?  We haven’t needed that additional load during all these cold winters gone by. So why should we suddenly need it now? Especially at a time when we’re trying to make America’s heating systems more efficient.

            Here’s the wackiest part. This homeowner finally decided what size the boiler should be, and then he told the contractors to base their quote on that size. Some backed off right away. They weren’t going to let the homeowner do the sizing, even if he agreed to take the responsibility. Other contractors told the homeowner that if he went with a boiler of that size, a size they considered too small, then he would also have to have a boiler-feed pump, which happens to be nearly as large as the boiler itself. This is in a single-family house. Imagine needing a boiler-feed pump in a single-family house. Oh, my.

            And hey, Mr. Wholesaler! That new boiler you sold me is using more fuel than the old one! The homeowner is screaming! You need to call the factory and tell them they got a big problem!

            And what are you going to do me?