Steam Heat vs. hot water heating
We will soon start renovating a 2 family and will also have to update the heating system. The boiler is now running on steam but I noticed that it can be converted to hot water (it’s a pretty new boiler). Is it worth changing the system to hot water? Which of the two systems is more efficient and any idea how much it would cost to convert to hot water?
brooklyntoqueens
in Brownstoner Renovation 11 years and 4 months ago
8
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8 replies
Master Plvmber | 11 years and 4 months ago
What a bizarre posting that was.
eman134 | 11 years and 4 months ago
stop pimping for ezbz…no one uses it
3l7e2t5i | 11 years and 4 months ago
Some other things to consider. Steam radiators, which might run about 1 1/2# of pressure, would be asked to run at 12-20# of pressure. They may leak. It’s true that hot water is more efficient because it requires lower water temperatures, but junking a working steam system doesn’t make sense. If you want to install an indirect water heater, such as an Ergomax. These are nice if you have large demands for hot water. They also retain their heat loss to about 1/2 degree an hour in standby vs. 10 +- degrees per hour with a boiler. If you have average use of hot water, there is nothing wrong at all with the coil that can be found in a boiler. Your current boiler may even be able to be fitted with a coil. Steam is most efficient in tall structures and less in large footprint low buildings. If it were me, I know I’d go with the current steam system and come up with something else in the addition. I know electricity is expensive, but have you considered an electric boiler? They hang on the wall and will heat your addition with hot water. You can find a local plumber that is reasonable through myezbz.com. I found my plumber through ezbz just by posting a free inquiry. Hope this helps.
ellenlourie | 11 years and 4 months ago
Bruce, TRVs for one pipe steam system allow room to room temperature setting and adjustment, not zone to zone. It is like having thermostat in each room. And yes homeowner can lower temperature in any room if he wish. For hot water systems TRVs do same thing. TRVs for hot water system hunt for the setpoint temperature by modulating flow trough radiator. Manifolded and/or zoned system, unless you use indoor or outdoor reset, just shuts flow to the zone on setpoint. And this what kills efficiency dead. Future separation of the heating system? Why? Properly done heating system in standard brownstone brings bill for heating for one year around $1800\. Why spend your own thousands of dollars to give savings to the tenant? Heating portion of the rental payment pays for whole house heating. So owner gets heat for free.
brucef | 11 years and 4 months ago
Gennady, I cannot quibble with your facts, the question is how does it relate to the issues of brownstone ownership. As an owner, every capital investment has to make dollars and sense, and if the challenge is evenly heating a given building to a finite temperature, well then the savings versus investment have to be weighed. As an owner, that really is not the correct challenge. Suppose the building owner is lucky enough to vacation for two weeks during the heating season. Does the inexpensive but carefully balanced steam system allow the owner to reduce the T-stat for just the owner’s space while keeping the tenant warm? We call the “zoning” obsession “future proofing”. With each zone terminating at a manifold in the cellar, should the gas/oil/electric balance tilt over time, no intrusion into the finished surfaces in the living spaces will be necessary to for instance, install a separate boiler for a rental space or two. Our advice, if you are renovating now, and there is already open walls, now is the time to plumb hot water zones. Can you spell – “Resale Value”
ellenlourie | 11 years and 4 months ago
Properly set up steam system will not be much less effective compared to hot water system and definitely not worth expense. And seeing how cheaply hot water systems done nowadays it is better stick to steam system you have. Just green it up and you will not see much of a difference neither in comfort nor savings. Efficiency of the modulating condensing boiler will be in low 90s and steam boiler in low 80s, also condensing adds up around 5%, But considering total obsession of the public with zoning all these advantages of modern boilers are lost. There are ways of tune up and upgrade of existing steam system, but they are very little known and rarely offered on the market.
brucef | 11 years and 4 months ago
To elaborate on the above: The greater efficiency of hot water is two-fold. It is straight up more efficient, but much more easily “Zonable?”. The greatest savings comes with the ability to heat separate zones with separate t-stats. Floor that is warm anyway, don’t bother to heat it. A floor you aren’t using, lower the temps there. This granularity dwarfs the greater straight out efficiency. While re-plumbing for hot water, there is every opportunity to separately zone the floors etc. By thinking of the convertibility of the boiler, you are missing the bigger picture, the savings and comfort of warm where you want it. We have had great success flushing existing cast iron radiators, carefully tapping for new bushings etc. Not what most tradesmen like to spend their time doing, but where there’s a will, there’s a way.
Master Plvmber | 11 years and 4 months ago
Hot water can be significantly more efficient than steam. 3 heated floors is going to cost you a minimum of $40K to design and install well from scratch.