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Hot water zone or steam to heat upstairs of cape?

mizmary
mizmary Member Posts: 9
edited June 2021 in THE MAIN WALL
Hi,
I live in a 1250 sq. foot, 1939 cape in Worcester, MA. The first floor is heated by a steam boiler (single pipe system) while the upstairs has electric baseboards. I had to replace the original boiler a few years ago and asked my plumber (not a steam "expert" per se) about getting heat to the upstairs. He suggested adding a hot water loop to the system and I believe he did a few things during the boiler install to facilitate doing so when I decided it was time. I recently asked the same question of a steam expert who was servicing the system and he indicated it would be much easier to pipe the steam upstairs and add radiators. The upstairs is approximately 350 sq. feet. Which is the better approach?
Thanks for any input!
Mary

Comments

  • mattmia2
    mattmia2 Member Posts: 9,572
    It depends. The steam would be less maintenance and simpler assuming the boiler can support the EDR but you would need to get steam piping up there and would need to get some sort of radiators or convectors that will work with steam.

    Hot water could be easier to get the piping up through the building and get some sort of heat emitters for and could be controlled separately from the steam side of the system but it would be somewhat more complex and would be more difficult to keep free of air unless you set it up as a pressurized hot water loop with a heat exchanger or a tankless coil in the boiler.

    The separately controllable between floors is a great benefit of the hot water loop since 2 different floors of a building never have the same heating load.
    mizmary
  • mizmary
    mizmary Member Posts: 9
    @mattmia2 thanks for your reply. It was my understanding that the boiler can support the additional heating load. However, it would be great to have separate zones for the two floors.
  • Jamie Hall
    Jamie Hall Member Posts: 23,162
    Either one will work, though as @mattmia2 notes it would be much easier to zone with hot water.

    However, I'll go a bit farther than @mattmia2 on one point. He implies that it could be set up as a non-pressurized system. Don't even think about doing that. You will need a heat exchanger powered by the boiler -- that can be direct from the boiler -- but the actual heating loop will have to be pressurized or you'll be fighting air in it all the time -- and any air at all in it would shut it down. No heat.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    mattmia2mizmary
  • bburd
    bburd Member Posts: 909
    edited June 2021
    If it were my house, I would decide how important separate zoning is; then probably get estimates for both approaches.

    A hot water zone would cost more to maintain, because it is more complicated:  the heat exchanger, pump, expansion tank and air separator will need repair or replacement as the system ages.

    With steam, there is not much to need fixing besides radiator shutoff valves and air vents, which are usually reliable. 

    If you go with steam, use the same type of radiator that you have downstairs. Mixing cast iron radiators with copper fin tube on the same thermostat zone will cause underheating of the rooms with fin tube or overheating of the rooms with cast iron. The two materials have very different thermal mass.

    If you do hot water as a separate zone, you can use any type of radiation that meets the heating load.

    Bburd
    mizmary
  • mizmary
    mizmary Member Posts: 9
    @Jamie Hall @bburd Thanks for your responses. I have a quote for the steam. Any guesses as to the relative initial cost of the two approaches? I'm not sure how important separate zoning *should* be? Do you think there's a high risk of not getting enough heat upstairs with the steam? I know *enough* is subjective. I wouldn't mind its being somewhat cooler, but do not have any sense of what the differential might be? Adjusting the radiator valves/vents would allow some adjustability, right? I do like the ease of steam in terms of maintenance and reliability. Ductless mini splits seem to be very popular right now -- does it make any sense to consider these? Thanks again.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,453
    @mizmary

    If you have a steam guy that knows what he is doing (not easy to find) I would go with steam. If not go with water
    mizmaryethicalpaul
  • Jamie Hall
    Jamie Hall Member Posts: 23,162
    In direct response to your third question, @mizmary , there's no risk at all of not getting enough heat upstairs. How much heat you get upstairs will be entirely a matter of how much radiator gets installed, and if your steam guy is any good at all, he (or she!) will have chosen the radiator size for each room to match the room. Then you can fine tune it with the venting.

    The first question -- cost -- is a little hard to quantify. The steam will probably be somewhat less expensive, but I wouldn't expect it to me much less. It's really in the additional complexity and widgets required for the hot water to the additional difficulty of running the pipes for the steam.

    Ductless minisplits are wonderful gadgets. In New England, at least, except right along the southern shore areas, they are not a good substitute to use for base heating loads or for heating when it's really cold out -- at least not in my opinion, at the present state of the art. They have some very attractive qualities, particularly in the "shoulder" seasons and summer (built in air conditioning), but the enthusiasm tends to dim when it's 0 out with a 30 mph wind and you can't find enough sweaters....
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • mizmary
    mizmary Member Posts: 9
    edited June 2021
    @Jamie Hall thanks, I figured the ductless mini splits would be insufficient for the heating needs. Though the air conditioning is real appealing. Oh, the joys of owning a cape!
    So, it's not a matter of the boiler shutting down in response to the thermostat on the first floor before a comfortable temp is reached on the second floor?
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,823
    @mizmary the ductless minisplits (cold climate type from Mitsubishi, Fujitsu, LG, etc.) will have no problem with your climate. You also have electric baseboard you could keep just in case it gets to -20 degrees. They come in several indoor "shapes", so take a look at the options in case one looks particularly good in this room. The most obvious benefit besides their high efficiency would be air conditioning.
    ethicalpaulmizmary
  • mizmary
    mizmary Member Posts: 9
    @Hot_water_fan Thanks, that option crossed my mind as well. Worth considering to improve on the heating situation while adding air conditioning.
  • bburd
    bburd Member Posts: 909
    @mizmary@Jamie Hall’s response is spot on. You should have no trouble getting enough heat upstairs if the new radiators are correctly sized.

    Bburd
    mizmary
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,823
    What's the motivation for switching heat sources upstairs? Is it safe to assume the steam quote was high enough that you haven't made the call yet?
  • mizmary
    mizmary Member Posts: 9
    @Hot_water_fan That's a good question! I started thinking about it when I thought I would have to sell my house to move closer to work (that's no longer the case). I believed that potential buyers would cringe at the thought of electric baseboards. And, I feel like heating with electric baseboards is like throwing money out the window. Having to replace my steam boiler also led me to consider the change. However, the cost of getting the steam upstairs is high enough that it would be a very long time before I would recoup any of the money spent. I have not yet received a quote for a hot water loop.
    Am wondering whether my money might be better spent on more efficiently cooling the upstairs in the summers.
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    Another thought...it is likely with a house that small that any steam boiler you have is currently oversized to only heat the first floor. It will likely run better with additional radiation installed upstairs. I recommend running the pipes in the interior space (in an inconspicuous corner is best) rather than in the cold wall spaces.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    mizmary
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,823
    @mizmary okay perfect! It’s a difficult situation for you because you have all the expense of running steam, but you’re only serving 350 sqft so you’ll be hard pressed to make up the initial cost with energy savings and who knows if a potential, future buyer will value the steam vs electric at anything close to what you’ll spend on it. The minisplit probably matches the energy cost with lower install cost and cooling capability. Is it multiple rooms on this floor?
  • Jamie Hall
    Jamie Hall Member Posts: 23,162
    Quite right to think that people might cringe at the thought of electric baseboards. Though "cringe" isn't quite the word; unless you dropped your asking enough to cover replacement with something that worked, they'd run for the hills.

    There are some rather amazing claims for the performance of heat pumps -- and mini-splits -- in colder climates. I am, quite frankly, skeptical. I will quite happily say that the very best hyper heat units will work down to an ambient of 0 Fahrenheit. Are they the best way to heat a structure at those temperatures? @Hot_water_fan would claim that they work fine down to -20 F, but it is worth noting that the manufacturers do not make such a claim. Mitsubishi's HyperHeat units -- which I regard as among the best -- do claim they will work down to 0 with good efficiency. They make no claim, however, for ambients below that temperature. I personally do not think it would be prudent to have, as the main heating source, a system which might -- or might not -- work if the design temperature for the structure were less than 0. As it happens, that is the design temperature for immediate coastal southern New England. Even as closely down east as Portland, Maine, the design is -5. Concord,, New Hampshire -- which is representative of inland Massachusetts and Connecticut as well, is -15.

    I'd go with with the steam, myself.

    For what it's worth, for reference for you, Cedric's home -- the main place I care for -- has routinely recorded outdoor temperatures of -10 for days at a time, though I've never in 20 years seen it colder than -25. The heat is steam, and there is one centrally located thermostat. The temperature throughout the house (7,000 square feet on 3 floors) is even within about 3 degrees, except on very windy days
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • mizmary
    mizmary Member Posts: 9
    @Hot_water_fan yes, a 10X15 bedroom, 10x10 bedroom, and bathroom
  • mizmary
    mizmary Member Posts: 9
    @ethicalpaul yes, the boiler is oversized. So, by "run better", you mean the overall efficiency will be improved? Thanks for your thoughts.
  • mizmary
    mizmary Member Posts: 9
    thanks, @Jamie Hall, I don't disagree with you about the heat pumps/minisplits as a primary heat source. Sounds like most opinions are leaning towards expanding the steam.
  • Hot_water_fan
    Hot_water_fan Member Posts: 1,823
    @mizmary The resale value portion is such a wildcard. You could spend thousands and recoup absolutely nothing, I'd be skeptical of any claims, but if anyone has data I'd listen. I think the second story heating source is maybe the 50th most important attribute of a house for sale, unless you're selling to someone on this forum! Cooling seems more valuable, but that's market specific, so do your own research.
    @Hot_water_fan would claim that they work fine down to -20 F, but it is worth noting that the manufacturers do not make such a claim.
    That's correct!! My bad. The manufacturer says their thermal lockout temp is -18, -14 restart temp. Maybe a hours per decade you'll need the electric resistance. Not a big deal.
    ethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited June 2021
    mizmary said:

    @ethicalpaul yes, the boiler is oversized. So, by "run better", you mean the overall efficiency will be improved? Thanks for your thoughts.

    Well "efficiency" is a tricky word. No, the boiler won't be much if any more efficient in terms of "heat energy gained out of fuel burned"

    But if you are seeing short cycles during calls for heat, these are likely to be reduced. The sq ft of radiation will be a better match for the steam produced by the boiler.

    One of the main benefits of running steam up there is after it's installed there's really no additional complexity, maintenance, or moving parts to worry about (OK other than vents). The steam will just go up there by itself and provide beautiful warmth to the occupants!

    I do agree with the above sentiment that the "method of second floor heating" is not any kind of maker or breaker for home buyers. They are far more interested in the kitchen fanciness and open floor plan.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    mizmary
  • jumper
    jumper Member Posts: 2,226
    I didn't expect significant difference but experienced improvement both in comfort and consumption when I replaced baseboards with ceiling height radiation. Some women do not like the look.
    mizmary