Help with choosing new heating system?

Midge

Hi. I live in MA and just bought a house with a 100-year old gas (steam) boiler, which I've been advised to replace. The radiators are also old and in bad condition, and I'd like to replace them, too.



The house is 100 years old, 1400 square feet, most of the living space on two levels, with a small finished room on the third floor.



-My first question is whether it's better to buy a new steam boiler and new thinner radiators that would take up less of the limited floor space, or whether now would be a good time to switch to a hot-water system, also with thinner free-standing radiators (not sure what they're actually called, but baseboard radiators would not look right in this old house)?



-I know that hot water would be more efficient but will the additional construction/mess/cost be worth it?



-How much more expensive should a hot water system be?



-Also, the guy who gave me a bid on doing the hot water system wants to use pex piping. I'm not crazy about this idea, and would love some input on this. He said copper would cost $2800 more.



And again, my main question is, if you're replacing your boiler and radiators anyway, is it worth it to switch to hot water?



Thanks,

Midge

kcopp

Before you take....

out the sawzsall...  How "bad" is the old steam system. I would sight unseen advise you to get a steam pro out to look at keeping the steam. If done right a new boiler w/ all the right venting can be nearly as efficint as the hot water systems. Where in Mass? There are a bunch of guys here from Mass.

Midge

The old steam system...

I don't know how good or bad the system is.

I know it's really old and the existing boiler was converted from coal to oil to gas. But I bought the place in the warm season, so I don't know much else about it.



I'm just trying to get a sense of whether it's wiser to take the opportunity to switch, while we're in the position of having to buy a new boiler and new radiators anyway.



I'm in Western MA.

kcopp

Charlie Garrity...

is in Lennoxdale , MA .He hangs out here a lot and can help. or look @ find a professional. on the key up top....kpc 

Jean-David Beyer

I know that hot water would be more efficient

I am not a heating contractor, but I am very interested in home heating. I happen to have hot water heating here, with the main (downstairs) heat being supplied by radiant heating copper tubing in the slab.



It is not obvious that hot water heating would be more efficient for you. It is true that for a hot water system with outdoor reset and a modulating boiler you can expect heating efficiencies at the boiler output of around 93% and even higher under less usual conditions. A good oil burning steam boiler could run at 86% efficiency.



But the efficiency at the output of the boiler is not the reason you buy a boiler. You want heat in the house. With hot water heating you need circulator(s), and possibly zone valves, and these use electricity, cost that does not show up in the efficiency of the boiler. These extra costs can reduce your efficiency some. I have four 85 watt circulators in my system and sometimes three of them run at the same time. About 250 watts. It mounts up. Similarly, if you drive regular baseboard heating or radiators with 180F water (a typical thing to do), your boiler will not condense so your efficiency can drop also, to something like 88%. That is not far from 86%. Steam does not require circulators or zone valves.



A well designed hot water system might be slightly more efficient than a steam system, but as they say, your mileage may vary.



As far as I know, PEX or PEX-Al-Pex piping is satisfactory. My house has all copper, but that was built in 1950 and I do not believe PEX was available then. With most steam systems, for example, you should probably be using neither PEX nor copper pipe, but steel.



One thing for sure is that much depends on the skill and knowledge of the contractor more than any particular brand.



It might be that your radiators are not as bad as you think, but only a qualified steam professional could tell you for sure.

Charlie from wmass

Hi Midge

How bad are the old radiators? One thing to keep in mind is that the new ones that are thinner also need to be longer for the same given height, sometimes much longer. I would be happy to check out what you have and give you my input. As I say I have an efficient truck so I can drive a fair distance to work on systems.

Steamhead

First of all

you shouldn't need all new radiators. Unless they've been abused, your current ones should work fine. Same with the steam piping.



Definitely replace that old boiler for better operating efficiency. Charlie Garrity sells some of the most efficient steam boilers out there. I'll second the recommendation for him.



Some of the newer hot-water boilers have higher advertised efficiencies, but some of these have had teething problems. Whether it's worth paying extra for this type of boiler as well as the rather steep cost of installing all new pipes and radiators, is questionable at best. Also, in an extended power failure a hot-water system can freeze up, but a steam system drains completely dry when it shuts off except for some pipes in the basement and the boiler itself.



If that were my house I'd stay with steam.

Midge

new system?

Thanks to those who responded.

I don't know if the radiators are in bad shape, but they don't look good (peeling, rusty, etc). Also, I am not crazy about how much space they take up.



ARe most people in this forum biased toward steam in general?



Thanks,

M.

Jean-David Beyer

Biased?

I am not even a contractor, and I have nothing to sell, so I may not be very biased in the choosing of hot water heat vs. steam heat. I am biased against forced hot air heat. I have lived in houses heated each of these ways. I do not like the noise of forced hot air, or the dust, or the constant temperature variations and drafts.



From what you have said here, it sounds to me that it would less expensive to rehabilitate your existing steam system, replacing the existing boiler, than to rip out everything and starting over from scratch. You are concerned about efficiency, and that is certainly a consideration. But it is easy to be confused or mislead by the numbers. I know I see numbers like 86% efficiency for steam boilers and 93% or more for modulating-condensing hot water boilers. But those numbers may be a little deceptive. First of all, both are probably much higher than what you have now, so you should see considerable improvement no matter which you pick.



Second, modulating-condensing boilers can achieve very high efficiencies, but they do not always do that. It depends mostly on how low the temperature of the water returning to the boiler after it has been through the radiators will be. The usual practice with hot water heat is to put 180F water in the radiators and expect 160F water coming back. If you do that, you will not get any condensing and the efficiency of the system will drop from the md 90s to 87% or so. To get the efficiencies you want from a mod-con boiler, you want the return water to be less than 130F, preferably a lot less. To get 95% efficiency, the return water temperature will need to be around 100F. And to heat your house at temperatures like that, you will need a lot of baseboard or equivalent amounts of other heat emitters.



And these efficiencies are just at the output of the boiler. With hot water, you need to consider the efficiency of moving the water around (typically with little pumps called circulators).  Steam systems do not require circulators; the steam moves itself. It is my impression that for you, the differences in real achieved efficiency may end up being too close together to use it for making your decision.



Another efficiency you might be concerned with is the value of money. If one system costs more than another, and is equivalent in all other respects, it may not make sense to go with the more expensive. Maybe I am biased. I hate the thought of ripping out walls to remove steam pipes and radiators and installing new pipe and heat emitters for a hot water system.



When all is said and done, you will probably do best to get the best heating contractor you can find and rely on his (or her) recommendations. The contractor should be one with experience with both types of heating, steam and hot water. There are several reasons. First, a good professional will almost certainly make the best recommendation. Any biases he has will be the result of years of experience in your area, with whatever boiler he recommends, his experience with suppliers, and more important: he will have actually seen your installation and know the issues. He will be the one who maintains and repairs it in the future, and he surely does not want to make things difficult for himself or expensive for you.

Midge

alternatives?

Thanks, JD, for the explanation. That makes sense to me.



I didn't necessarily realize that taking out the steam system would be a big mess. I thought the pipes in the basement would just be cut out. I once had to remove a steam pipe in my kitchen (which was in the way of the cabinet), so the plumber just cut it and pulled it through from one floor to the next. I guess I envisioned something similar and fairly simple for the removal of the rest of the steam pipes. Does it always involve cutting into walls?



If I were to get a new steam boiler, are there particular brands I should look at that are highest efficiency? Do they have the option of direct venting and including a hot water heater? Would it be super-expensive to buy the more low-profile steam radiators?



Re: new radiators, It's not that I want to waste money to save a little space. I have two issues:



1) These radiators look pretty terrible, so assuming they work well (which I don't even know), they would need to be carted away and sandblasted and repainted or else completely boxed in. By the time I did all that and had them brought back and reinstalled, I figure I might be halfway (cost-wise) toward buying new radiators.



2) My house is really small; the room sizes are mostly in the 10 x10 or 10 x 12 range (and one bedroom is a lot smaller), so the size of the radiators makes a big difference.



I am grateful for any suggestions.



Thanks.

Steamhead

For gas-fired residential steam

the Smith G8 and Slant/Fin Intrepid, fitted with power gas burners, offer the best efficiency. They have more heat-transfer surface available than the usual atmospheric gas boilers do, and the power burners can burn clean with less excess air carrying heat up the chimney.



Older radiators seem to have heavier cast-iron than new ones do. So they're plenty durable, and if one does leak it's usually at a push-nipple between two sections. This is relatively easy to fix. The peeling paint is probably due to painters using ordinary wall paint that can't handle the heat. When stripped and repainted with the proper high-temp paint, radiators usually look fantastic.



The only time I'd consider replacing all the radiators is if the house was tightened up, with better insulation, windows etc. This would reduce the house's heat loss, which would allow the use of smaller radiators.

Jean-David Beyer

Alternatives...

Remember that I am not a contractor.



You might not need to remove the old steam pipes. You could just leave them in the walls. I think that is messy and personally I would not care for it. If the contractor could get at them in a simple way, they could be cut off at both ends and pulled out. That might make putting new pipe easier. But you need a qualified contractor who has actually seen your existing system to decide.



If you look at this site for a while, you will see that there are several really expert steam professionals. I suppose they would work on hot water too. steamhead is one; boilerpro is another; and charlie from wmass is a third -- and he is probably close enough to you to look at, and probably to work on your system. I am incompetent to recommend a suitable boiler, and defer to the professionals.



A pro would check on the sizes of your existing radiators to see if they are the right size for your house. They might, if you are lucky, be just right, but if your house has had any improvements over the years, they may be too big. Likewise, if your house has been insulated, better windows installed, etc., it could be that your existing boiler is too big.



If it were just the appearance of the radiators, it could be that all they need is cleaning and painting with a suitable paint. Boxing in a radiator would probably reduce its efficiency. There is no substitute to getting a reliable pro in there.