More efficiency wanted, but keep the radiators

Dave Yates (PAH)

on the overall condition of your system. We converted a Tudor-style mansion from two-pipe steam to hot water using a Munchkin (customer driven choice) and he has tracked gas usage this past winter. According to his records, he reduced energy consumption by more than 50%.

In addition to proving a number of zones (6), we installed radiant under his newly installed stone floor in the kitchen and a hydro-air coil in the A/C duct serving the great room that's never been warm enough in past years utilizing a two-stage stat to kick up the heat via the coil when old man winter tries to put a chill on comfort. A damper closes to seal off the other rooms on that A/C zone and a by-pass relief damper ensures proper air flow without blowing the curtains off the windows!

As with any steam to water conversion, there's the possibility of leaks in distribution piping, radiators and other assorted fittings. Typically, there will be several to correct. In this case, not one single leak!

Worst case scenario? We did an old farm house that had cast iron baseboard & found that almost every section had hairline cracks radiating (on the back & away from view) outward from the air openings along the top. Major expense was incured by the HO to replace the BB. Also found concealed copper (!) behind one wall - rest was black iron - that had joints never soldered.

So, as long as you know the risks & are willing to go the distance, it can work quite well.

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=98&Step=30">To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"</A>

Laurie Schubert

Need to get more energy efficiency but keep the radiators

We would like to be more energy efficient (plus head off the predictions of high natural gas prices) by replacing our 1970's STEAM boiler with one of the new 'munchkin' HOT WATER systems, but I don't trust our nearly 90 year old steam pipes which run through our second floor. Could any one tell me if they have addressed the idea of fishing pex tubing through existing radiator steam pipes, so that they serve as a conduit for the pex (hot water tubing), then hooking them to the existing radiators. If I don't come up with a solution, I'm afraid my husband will put in a forced air furnace, which I feel will wreck the comfort and ambiance of our old house's radiant heat. (Help!)

Steve Whitbeck

You said your system was a steam one.
Do all of your radiators have two pipes coming off them?
If not then before you can convert to hot water from steam you will have to run the extra pipes.
If all have two pipes then just pressure test the existing piping and radiators to see that they don't leak.( 30 psi )
If nothing leaks then convert away.
You will need to change the valves on the radiators to hot water ones and drill out the steam traps on the radiators also.
You will have to flush out the entire system before you pipe it to the new munchkin boiler or the sediment will cause you some real nightmares.
Make sure you install a fine strainer on the return to the boiler.
The boiler will have to be piped primary / secondary.
Good Luck

Dave Stroman

Put your money where it counts

Does your steam system work okay now? Leave it alone and spend your money on other things like better insulation or windows or just a set back thermostat. You will tear your house apart puting in scorched air and will problably not save a dime in fuel costs. Plus you will not be as comfortable. A 90%+ boiler will not run at 90%+ unless you run the system below 130 degrees. Can you heat your house with 130 when it now uses 200+?

Steamhead

Laurie, the economics of converting

are doubtful.

Hot water runs at least 10 times the pressure of steam. If there are weak spots in pipes or radiators, they will leak.

Some steam radiators cannot handle hot water.

If you have a one-pipe system, you have to run all new return lines.

If you have a two-pipe system you may still need to repipe the returns- some are too small to handle hot water.

And a hot-water system can freeze. A steam system typically drains dry when shut down, except for the boiler and wet returns in the basement.

Can you tell I like steam?

I applaud your quest for better efficiency. However, you can make significant gains on steam systems if you know what you're doing. Tell us where you're located and more about your system (post some pics if you can) and we'll see what we can do.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Laurie Schubert

Yes, our radiators do have two pipes coming to/from them. I will work on getting pics posted so that someone could see if pex could work running inside the service/returns (conduit)...........if this is even a possibility in the first place. One would think that if electricians can fish electrical wire, pex could be fished through too(?) Also, a second question. Our system has a low point in the basement, where it seems everything converges and that is where the trap is located, yet away from the boiler. At the beginning of every heating season, we have a leak (or more) in this area, even though the pipes have just been replaced-over and over again in some circumstances. I understand the corrosiveness of the water condensate. Should the trap be opened and drained at the end of every heating season, to avoid making an annual contribution to our mechanical contractor's retirment fund? Thanks...Laurie

Steve Ebels

I would never

Advise you, or attempt myself, fishing pex through steel piping. Number 1. Pex would have a hard time making a 90* turn inside a steel elbow. Number 2. If it did make a turn it would really scrape and abraid as you pulled it further down the pipe whilst moving through said elbow. Number 3. The constant expansion/contraction of the pex would for sure eventually wear a hole in it at the point where it contacts the steel. More likely sooner than later.

The advice posted above is all good. What you wind up doing depends on a LOT of factors. My own personal course of action would be to address your building "envelope" IE. insulation, windows, weatherstripping etc. Get your present system in it's peak operating condition and leave it alone until such a time as the payback on your investment would be a reasonable amount of time. 5 to 7 years or something like that.

Hope this helps.

Dale

Question comes up alot

I guess it's several questions, first the money, what's a reasonable payback to you? A business is now less than one year, homeowners sometimes say 10 years. How long do you plan to stay in your house? Cost, steam will cost you more since you need 212 plus on days that 120 degrees would do. Do you ever want to zone? You can have your steam system fixed to be warm and quiet, how much? Depends, How much hot water do you use, modern DHW zone makes alot off the little munchkin. As to the pipes You could isolate and air test. Your house is probably balloon framed, you could probably have pex run to the second floor without too many holes cut in the wall. I too would forget about fishing pex except up straight runs of pipe cut off below the floor to the second floor. I see lots of 2 pipe steam converted very nicely to hot water. You can have heat anywhere you want it at whatever temp you want and save alot of fuel. If there's a contractor in your area that has done some of these with success I would get a price.

Steamhead

Laurie, I'll bet

you have a Vapor system. Most old, two-pipe residential steam systems were Vapor systems of one type or another. The exception would be if each radiator has a hand-operated valve on the return line as well as the supply, and an air vent. The latter is a two-pipe air-vent system. If you post some pictures of the radiator inlet and outlet fittings and any strange-looking devices around the boiler and the leaky trap, we can probably identify it.

Old Vapor systems were some of the best systems ever invented. They were designed to be quick, quiet and efficient. And if properly maintained, they will continue to be.

Vapor systems typically run at a maximum pressure of a half-pound. Air is vented at one or more central locations in the basement- this is why vents are not needed on the radiators.

The critical thing in most Vapor systems is to keep steam out of the dry return. Many systems use traps to do this. These are moving parts which do require maintenence. Parts are available for almost any trap you may have, including the leaker in the basement.

I wouldn't try to convert that system. It's much easier and cheaper to fix it. Tell us what area you're located in, I'm sure someone near you can help. If you're near Baltimore, e-mail me!

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"