Modifying a baseboard hydronic heating system?

RedOak

Hello to the board! First things first, I grew up on a farm in the south, so heating systems are not something that I grew up with and, consequently, I'm not well-versed in this regard. That being said, we purchased a home in the northeast about 15 months ago and, man, were we unprepared for the imminent winter!

After figuring out a way to dig ourselves out of the mountain snow, we began to notice that the house -- on windy days -- would not stay warm. In fact, the propane boiler and "finned" baseboards would run so much on those blustery days that the sight of the volume gauge on our 500-gallon propane tank, as it steadily dropped, sent us into a bit of a panic.

As it turned out, the previous owners must've experienced the same thing because there was a forced-air wood furnace already hooked up in the boiler room...so, after begging for cord wood from relatives and friends, we quickly fired up the wood stove and have been using it to heat the house ever since. The problem here is that the cord wood supplier in our area is very tough to deal with and, even when we get him to deliver his expensive wood, the quality is very mixed. Having written that, I must admit that buying wood to heat the house has been better than buying propane, which explains why we've stuck with wood as our primary heating fuel.

So one day I was with a friend, in his large garage, when I noticed that his wood furnace had an extra handle on the side. Out of curiosity, I asked him why his furnace had a handle that ours was missing, and, long story short, I was introduced to coal grates and, more to the point, the world of burning anthracite coal. So I contacted a friend of ours in upstate NY and asked him how he heats his older home, and the answer was: With a coal stoker. After asking him to explain the basics of a coal stoker to me, I immediately started to look into whether or not anthracite coal was available to us and, obviously, how much it costs to have it delivered. In the end, I found out that, yes, it's available and also that the cost per ton made it well worth further research.

After a lot of correspondence, reading and more conversation, we have decided that a coal stoker boiler should be a very good alternative to the small propane boiler that let us down during that first winter. So I've begun a search for a decent used boiler, but, in the interim, I've been asked a question that really has me thinking back to those cold windy days, and that is: Are you sure that you have enough "radiation" in your house to handle those really cold days?

As I just wrote, this question had me scratching my head, but I was also inclined to think that any hydronic baseboard heating system has to be supplied with enough hot water to begin with, so I spoke to a plumber about this. After considering the living area in our home -- and making a nearly exact guess at the size of our present propane boiler -- the plumber concluded that our boiler isn't big enough to meet our heating needs.

At this point in time, my thoughts are that, even if a new coal stoker boiler doesn't solve our heating problem entirely, we can always add more "emitters" to the 4 zones we presently have in the house and settle the issue that way...which leads me to another question: Can one add radiators to a baseboard hydronic heating zone?

It's probably obvious that I'm pretty green when it comes to all of this, but I am fairly sure about about a couple of things. One, it's better to heat the entire house than it is to blow hot air into one end of the house and move it around with electric fans...and, two, we would much rather have a heating system that doesn't require tending every 1.5 hours.

I hope that I've explained our issue clearly enough, but, if I haven't, I'd be happy to try to clarify it for anyone willing to offer their time.

Have a great weekend ~ Red

Jamie Hall

OK. Welcome to Heating Help -- and the northeast. My daughter in law is a southern girl, and I still laugh -- 20 years later -- when I recall her look at the first snowfall she'd ever seen...

Enough of that.

On staying warm. The first, and least expensive, thing to do with a house which isn't staying warm enough is to tighten up the house. No point in heating the great out of doors. Look for and fix all draughty doors -- windy days are great for that. Invest in storm windows. Even cheap ones are some use, and good ones (which can mount either inside or outside) are better than mid-range replacement windows. See if you can determine whether the house is insulated -- particularly the attic or roof -- and if not add insulation.

Now to your question: yes you can add radiation to a baseboard system. Either baseboard or real radiators. However, to do so one must determine whether the boiler itself can provide enough heat to the system -- and how the system is piped. Various ways of piping the system will mean different ways of piping the additional radiation. And, of course, if the boiler simply isn't big enough...

So the next thing to do after you tighten up the house is to determine the heat loss of the structure. There is a very good calculator for that here: https://www.slantfin.com/slantfin-heat-loss-calculator/ and if you go to the bottom of that web page there is a place (hard to find) to click to use it on your PC. Do it. Then compare the results with the rating on the boiler (it will be on the name plate somewhere).

Then take some pictures of the boiler and the associated piping and get back to us with the information and we'll see what we can do from there.

HVACNUT

At roughly 15K BTU per pound, how long do you figure a ton will last? 2-3-4 weeks? I'm clueless about coal and had to look it up. I also saw that anthracite coal accounts for only 2% of coal production. And its mostly used in the north east. So prices might soon go the way of LPG.
Proving once again that safe, dependable oil heat rules.

hot_rod

What is the typical efficiency of a coil fired boiler? Wood boilers that are gasification style run in the high 70%, OWF run in the 40%.

The cost of the fuel plus the efficiency is needed to get an accurate cost of creating useable heat energy. I'd guess a non gasification coal boiler in the 60%.

Common oil fired mid 80%, LP if a properly operated mod con low 90%?

HomerJSmith

When I was a kid, I worked for the inventor of the stoker stove (gravity furnace, I believe). At that time he was a grizzled old man and I was a young kid. What could he show me? I realized much later how I squandered my time with him.

HomerJSmith

I met an old guy once that was selling oak mill ends for fireplace burning for heat. He remarked to me on one of my purchases from him that he sent his four kids thru college on the wood he sold.
What he sold was cut up pallets that he got for free from businesses around town. That's initiative.

Icarus

Heat pump comes to mind. (Not withstanding previous comments of doing a proper energy audit to address heat loss issues...). Mini splits and or hot water heat pump (Sanden or Nyle) coupled to your boiler, with a good boiler guy doing the install. Propane gets really expensive some places and at some times of the year. Also consider a second tank, to buy in bulk in the summer when it is typically cheaper.

Icarus

PS Heat pump may not be the cheapest option of operation in bitter cold (~10-15f or colder) but over the course of the season it might well prove to be.

retiredguy

So, as @Jamie Hall stated, tighten up the house first. Start with the attic, then go to windows (storm or complete replacements), next is the wall insulation and last is the heating system. You may find out that the heating system as it is now is oversized for the area you are heating. If you are going to purchase and install an anthracite stoker, purchase it from a reliable dealer that can inspect the present wood boiler to make sure that you can burn anthracite coal efficiently. Not all units can burn different types of fuels without some internal changes in the fire box.. Let me explain; the burning of soft coal requires under fire air to control the speed of the burning fuel and over the fire air to promote the burning of the gases that escape when the coal is heated and to help with the cleaning up of the dirty burning coal. Anthracite coal burning requires the majority of the combustion air to be from underneath with very little "over the fire" air. Soft coal burns yellow and sooty and anthracite (hard) coal usually burns with a very clean blue flame. One last thing, soft coal is way less expensive than hard coal but requires constant cleaning of the boiler, the flue pipe, the chimney and everything associated with it. Dont go "soft coal" your wife will divorce you. my 2 cents

Ironman

You've got the cart before the horse.

You need to do the heat loss calculation and a radiation survey BEFORE deciding that you need another boiler.

I can't recall the last time that I saw an under-sized boiler in my 45+ years of doing this. They are almost always over-sized.

It could well be that you're radiation is under-sized and that's the reason that your not getting sufficient heat. Standard BBs are good for about 500 btus per lineal foot of element @ 170* Average Water Temp. That's the number that you need to use in spite of what you may see in some spec sheets.

It's not uncommon to find houses that once had an oil boiler and under-sized BBs. The installer cheaped out on the radiation and turned the SWT upto 195*+ to compensate for the lack of radiation. You can't do that with a gas mod/con since 180* is usually the highest the SWT can be set.

As Jamie said, tighten up the house and do the heat loss calc first.

RedOak

Ironman said:

You've got the cart before the horse.

You need to do the heat loss calculation and a radiation survey BEFORE deciding that you need another boiler.

I can't recall the last time that I saw an under-sized boiler in my 45+ years of doing this. They are almost always over-sized.

It could well be that you're radiation is under-sized and that's the reason that your not getting sufficient heat. Standard BBs are good for about 500 btus per lineal foot of element @ 170* Average Water Temp. That's the number that you need to use in spite of what you may see in some spec sheets.

It's not uncommon to find houses that once had an oil boiler and under-sized BBs. The installer cheaped out on the radiation and turned the SWT upto 195*+ to compensate for the lack of radiation. You can't do that with a gas mod/con since 180* is usually the highest the SWT can be set.

As Jamie said, tighten up the house and do the heat loss calc first.

These are really great comments, but, like myself, I think that Ironman read all of them and put together a great summary (above).

No doubt, "tightening up the house" makes a lot of sense. I also wanted to clarify that we presently have a propane boiler and, tight house or not, the cost of propane is prohibitive here. Cord wood, as I touched on in the original post, is a real pain in the neck to get delivered, but that pales in comparison to the time lost in tending the stove. In short, burning wood has proven to be unacceptable, as well...so we will definitely be moving on to something else.

As I know folks in this area who have gotten rid of their oil tanks and are now happily burning coal for heat, it's hard not to put anthracite at the top of the list, but, as one poster pointed out, the price of hard coal could very well be on the rise. Having written that, however, any type of fuel could be on the rise...and, in fact, I recall a fellow who built his new house, about 11 years ago, who openly spoke about how great his propane system was.

As soon as I get some time for it, I'll try to download and install the slantfin utility that poster Jamie Hall turned me onto. If I can get it to work on my MacBook Pro, I'll definitely give 'er a go and, with a little luck, get back to the thread with more information.

Thanks very much and, by all means, I'd love to read more thoughts about this. Have a great weekend ~ Red

Jamie Hall

Just a couple of minor thoughts here, @RedOak . First, I think that you may find that, per BTU delivered, the cost of coal, and oil are not much different, and the cost of propane, on the average, isn't that much different either. Propane costs do vary a great deal more than coal or oil, however.

The other thought is this: before you put a lot of work or even though into a coal or wood burning boiler for your house, check with you local authority having jurisdiction. In some towns and cities, new installs simply aren't permitted. Also check with your homeowner's insurance (they may not cover the installation -- they may not cover the house with the installation, either) and your mortgage holder (it may invalidate some conditions of your mortgage).

JUGHNE

Assuming this is an older house, the condition of the chimney in use should be a major safety concern.
Wood and coal burning require a pretty solid chimney.
Is your LP boiler and water heater? using the same chimney?

RedOak

> @JUGHNE said:
> Assuming this is an older house, the condition of the chimney in use should be a major safety concern.
> Wood and coal burning require a pretty solid chimney.
> Is your LP boiler and water heater? using the same chimney?

The house is about 30 years old now and, yes, the new (proposed) boiler will exhaust smoke through a solid masonry chimney. It has been inspected and is NOT going to be shared with any other appliance of any kind.

The propane boiler we stopped using to heat the home with uses a separate exhaust port at the opposite corner of our large basement.

RedOak

As practically everyone knows, 2020 has been one loooong year, but we did manage to make some progress regarding the heating system in our home. Although I was unable to run the slantfin heating calculator, we did manage to have a couple of people come out and take a look at the concern areas identified in this thread. First, we have an above average amount of insulation in our attic space. Next, we have pretty good windows and sliders (both double pane) in the house. No, neither are top of the line, but, relatively speaking, they're not bad, either. The one area that was identified as playing a significant part in air leakage was around the three (swinging) exterior doors -- and all three of them have now been addressed. To close out the insulation aspect of our project, we were told that the house is indeed insulated, but, after talking to more than one "expert," it became clear to us that you can never have enough of it. The major source of air leakage was around our exterior doors and, once again, that has been rectified.

After a lot of research (including sourcing the fuel itself) and hunting around the region, we were able to inspect, purchase and take delivery of a (anthracite) coal boiler system for a reasonable amount of money. After processing enough cord wood to get us through the winter season, we are finally at a point now where we can devote our "free time" to the coal boiler. Needless to say, it's not the ideal time to be taking the system apart, but it's in an enclosed area and, given how things have gone for us this year, this is the first chance we've had to get back to the heating project in earnest.

After removing the rear insulated covers on the boiler, it was verified that the domestic hot water (DHW) section of the boiler is leak free, so that was a [U]huge[/U] relief for us. I'm still in the process of removing some of the electronic controls that support the boiler, but, so far, the boiler looks pretty good.

So that's an update to the thread. When I have more to share, I will add more information.

By the way, I forgot to mention that one of the HVAC guys we had out to the house actually laughed at our propane boiler and, in the end, asked us the obvious question: Why do you think that the previous owners built that big covered wood shed and installed a wood furnace? In addition, our propane delivery man told us this summer that the previous owners used to have heating oil delivered to the house. As we never actually met the previous owners, I guess that we'll never really know why they converted from oil to the propane boiler system (in 2014)?

Canucker

They may have converted to propane so they could get a condensing boiler in the future. It sounds like they were preparing for the inevitable day, when heating with wood, where the spirit is willing to cut, stack and feed the fire, but the body is not.