For old row house, steam heat or hot water?

PittsburghRowHouse

Hi all,

I am new to homeownership and heating installation. I just bought a duplex in Pittsburgh, Pa, with a studio on the first floor and a two-story house on the second. Having lived in New York City for many years, I've become a big fan of steam heat. The house currently has forced air, which I want to get rid of and replace with steam. However, my general contractor and local HVAC company are trying to convince me to me to use hot water instead. I've read many threads on HeatingHelp and I can't find a definitive answer, so I want to start a new thread.

As background, the house is three stories, brick, a little under 2,500 square feet, and will be fully insulated. All the walls and ceilings are already down (we're doing a full renovation). There is no basement, so the boiler would go on the first floor, which is the same floor the studio apartment is on. I am of course budget conscious, but I plan on being one of those few folks that lives in their house for their lifetime, so I am willing to pay for quality that will be efficient over the long-term.

The reasons I think I want steam are:
1. Quality of the radiant heat (moist, not dry; no dust pushed through the house)
2. Durability of the system (a good one can last more than a 100 years; stapling pex to the bottom of the floors does not sound any where near as durable)
3. If properly installed, can be an efficient way to heat the house
4. The ability to shut off a radiator in a room if it is unoccupied (we've got a first floor apartment and will have unoccupied bedrooms for the first few years)
5. Fact that some spaces can be heated w/o a radiator (many rooms in NYC only have an exposed pipe, for example)
6. I like the look of radiators
7. The fact that the pipes won't freeze if we lose power
8. No risk of water leaks
10. If something goes wrong, pipes are accessible (w/ hot water ceilings would need to be ripped out)
11. Doesn't use water like a hot water system, thus doesn't impact our water bill
12. I personally would enjoy learning to maintain a system like a steam (but, perhaps a similar level of handyness is required for hot water)

Here's what the HVAC professional had to say:
"A steam boiler is either on or off and at best is 82% energy efficient. To make the steam the water has to get to temperature to begin making steam. The boiler does not know if the outdoor temperature is 0 degrees or 50 degrees. All it knows it has to get up to temperature to make steam. A modulating water boiler can get up to 96% and can vary the water temperature depending on the outdoor temperature. Instead of operating at 80,000 btu when it's 0 degrees outside, it can run at 40,000 btu’s when it's 50 degrees outside and burning less gas. The piping on a steam system is normally a steel pipe compared to a copper. Since the steam will cool down and condense after the radiators or baseboard, this condensate piping needs to slope downward towards the boiler for a gravity feed back to the boiler. You are also very limited on either the radiators or steam baseboard. Hot water has many different styles of radiators, steel panel radiators towel warming racks, baseboard and radiant floor heat. We could install a system that would have the PEX tubing stapled up to the bottom of the floor joist and they would not need any baseboard or radiators."

From what I've read here and in Dan Holohan's The Lost Art of Steam Heating, I am skeptical of this assessment. For one, it seems like he's just describing how steam works... these things don't have to be drawbacks if done right (right?). Two, from what I've read, those efficiency measures don't seem to be apples-to-apples; steam can be just as efficient as hot water (right?).

I am really in a bind here. This is such a big decision to make and I don't want to start down the wrong path because I was getting the wrong advice. I would appreciate any insight the The Wall can provide!

Steamhead

If I were doing your house, I'd do a mini-tube steam system. Go here to see what that is:

http://forum.heatinghelp.com/discussion/131555/new-steam-mini-tube-system-installed-in-my-own-house-iron-fireman-style

http://forum.heatinghelp.com/discussion/151994/new-steam-mini-tube-installation-in-ohio

Gordy

#2 plenty of 100 year old converted gravity systems still going.
#11 is wrong. Once filled a hot water system is done using water.

Gordy

You have lived with steam, but have you lived with hot water heat? Especially radiant?

Bob Bona_4

#4 is not doable if it's 1 pipe steam. Forget about #5, it's a happenstance if an exposed pipe is in a room, you cannot quantify the "free" heat, and the pipe is supposed to be insulated anyway. #10, steam can leak too, so that's a moot point.

Your pro's statements are correct.

PittsburghRowHouse

Hey @Steamhead, thanks for the links on mini-tube steam system. What do you recommend as more efficient over the long-term, a mini-tube steam system or radiant hot water?

Everyone else, a big thanks for weighing in. I appreciate you all giving a rookie your 2 cents and clarifying the things I didn't understand. (I am definitely leaning more toward hot water now, although the appeal of steam isn't totally broken.)

PittsburghRowHouse

@Gordy, no I haven't lived with hot water heat. You think it has all the positives of steam? Thanks for chiming in.

ChrisJ

@Gordy is currently living with forced hot air, his points are moot.


Steam will do better in any units that may be at risk for freezing.
Steam won't need to be bled and there's no pumps or bladder tanks to fail.

I prefer steam, but hot water is fine if done right.

Hot water will likely be slightly more efficient when compared to a properly working steam system.

Gordy

Temporary Chris.

Freezing pipes is such a weak argument.

ChrisJ

Gordy said:

Temporary Chris.

Freezing pipes is such a weak argument.

Tell that to those who have had to deal with it. I don't think they found it to be very weak. In fact, the two cases I know of were a disaster and extremely expensive to repair. With steam, neither would have happened.

jumper

Panel rads can use steam. I'd mount them high. Search IGOR on this site.

Gordy

Temporary Chris.

Freezing pipes is such a weak argument.

ChrisJ said:

Gordy said:

Temporary Chris.

Freezing pipes is such a weak argument.

Tell that to those who have had to deal with it. I don't think they found it to be very weak. In fact, the two cases I know of were a disaster and extremely expensive to repair. With steam, neither would have happened.

Weak, and rare cases of incompetence by builders, and or homeowners.

Tell me Chris if you have steam heat you don't have domestic water?

If I just had to have pipes freeze I would rather it be a 15psi closed system with x amount of water than a domestic side 60 psi with endless water.

Tinman

If you had an existing steam system, I would recommend keeping it 95% of the time.

Starting from scratch with the ability to do anything you want, a modulating condensing hot water boiler would be my recommendation. Dave Yates has an excellent tutorial on this very subject at heatspring.com.

ChrisJ

Gordy said:

Temporary Chris.

Freezing pipes is such a weak argument.

ChrisJ said:

Gordy said:

Temporary Chris.

Freezing pipes is such a weak argument.

Tell that to those who have had to deal with it. I don't think they found it to be very weak. In fact, the two cases I know of were a disaster and extremely expensive to repair. With steam, neither would have happened.

Weak, and rare cases of incompetence by builders, and or homeowners.

Tell me Chris if you have steam heat you don't have domestic water?

If I just had to have pipes freeze I would rather it be a 15psi closed system with x amount of water than a domestic side 60 psi with endless water.

Yes I do, but not along outside walls which will likely freeze first.

My initial posting was in my opinion, fair. I don't understand why you have a problem with it.

I'm thinking that forced hot air is making you grumpy.

Gordy

Hi Chris,
I'm trying to help you out. If you want to promote your fondness of steam heat use better arguments. That's all.

I have no problem with steam heat. The OP seems passionate for it, yet not sure. Also some misinformation.

Piping size for steam is a minus, along with having to maintain proper pitch. Existing construction may not lend itself well. I'm assuming that's why mini tube was suggested. Pipe size for hot water is not an issue. If freezing pipes is a concern just add glycol

Paul48

From scratch....hands down......heavily insulated, over-radiated, mod/con.

Steamhead

PittsburghRowHouse said:

Hey @Steamhead, thanks for the links on mini-tube steam system. What do you recommend as more efficient over the long-term, a mini-tube steam system or radiant hot water?

About the same. The "mod-con" hot-water boilers mentioned in some posts in this thread do have higher advertised efficiencies, but they tend not to last as long as regular cast-iron boilers, and they require more maintenance, without which their efficiency drops. Also, if they break down, parts are often several days away or longer and are more expensive. So as far as the money you will spend, it's pretty much the same.

Paul48

There's been a lot of talk , lately about water quality, and the new steam boilers. In order to get the life out of the boiler, your water chemistry has to be right. Maybe( I don't know), if as much time was spent on water quality for a mod/con, there would be less maintenance needed.

Gordy

It still all comes down to the ability to implement the infrastructure for steam verses hot water. Does the site lend itself to steam piping, or hot water better.

Loving steam heat benefits, and the rads is one thing. Connecting the boiler to the rads is another matter over looked. By the Client.

Gordy

By the way @Steamhead presents a plausible argument in favor of steam.

Tinman

Parts availability - I'm of the opinion that if you're a contractor and you're going to offer a particular mod con, it's your responsibility to stock the most common parts that may be needed. It would be a crapshoot if you left that up to the supply houses, similar to what @Steamhead said.

JUGHNE

On some HW boiler replacements, the lack of a solid chimney could be the deciding factor to go with ModCon boilers.
Could be considerable initial expense.

Not all existing masonry chimneys can have a liner installed.
If your project has a complete remodel then a B vent is doable.
But to punch one up 3 stories thru a 100 year old house can make you very unpopular with owners.

PittsburghRowHouse

Hi all, I've decided to go with hot water. It was a combination of the advice here, where most folks seemed to think hot water was the way to go, plus the fact hardly anyone in Pittsburgh has steam (it's either forced air or hot water). I figured it would be hard to find folks to service the system. Many thanks for the advice!

Bob Bona_4

Good plan. You'll find it has many options and flexibility. Good luck!