Converting to hydro air - worth replacing Thermodynamics S-125?

Icy L.I.

First, my apologies for the breach of etiquette on pricing.

The monoflo is being scrapped largely because it doesn't work well, loses pressure (leak cannot be located), has uninsulated pipes run in an inaccessible crawlspace that gets very cold, and other sections that run through an uninsulated concrete slab (best guess as to where the slow leak is). I share your view and would prefer anything above forced air, but it was the most economical way to address shortfalls of existing system and deal with needs of renovated space.

While we are replacing windows and doors, they should show only minor improvement versus existing which are comparable. Insulation will be modestly better, but I'd estimate that any gain will be offset by additional square footage.

Calcs, I believe, have been done. Existing boiler is right-sized to slightly under according to HVAC guy. I guess what I'm really wondering is for similarly sized boilers, how to figure any savings from greater efficiency so that I can estimate the pay back period.

Existing is heating oil and I plan to stay with that. Have a brand new tank and believe that this country will be NG constrained in coming years due to shift from coal for power generation (but that's an aside).

Thanks for the response.

Icy L.I.

converting to hydro air - replace S125?

Hi all,

We are doing some major renovations to a 50's ranch on Long Island, including adding more living space on the second floor. As part of the work, we will be scrapping the existing monoflo hydronic system with in-wall convectors and will add a hydro-air coil to an existing central AC handler on the first floor as well as add a new handler with coil for the upstairs.

The question: Existing boiler is a Thermodynamics S-125, age unknown but guessing 10+ years old. In addition to the hydronic system which is being scrapped, it provides hot water via an indirect system which is 3 years old. Thinking that with all of the repiping for the conversion this was a logical time to switch to a new, more efficient boiler, I asked contractor for quote to replace S-125 with a new unit. Quotes I received were for a Weil-McLain ($5850) or Weil-McLain Ultra ($7050). Quote indicates 5 section, 2 zone and also includes the cost to build an elevated platform for new boiler to meet local code for garage location. S-125 has an efficiecny sticker which says 82.9 (looks to be at the lower end of the efficiency scale on the sticker). In a typical winter, I use 8-900 gallons of HO. Does it make sense to upgrade and which option would be better?

Sorry for the newbie question and omitting any necessary stats. I'm happy to supply any other info that is needed.

Steamhead (in transit)

To begin with

by going to hydro-air you will sacrifice a lot of comfort. Moving air makes you feel cooler. This is great in the summer but bad in the winter. In the winter you and your family will be tempted to turn up the thermostat as the moving air carries heat away from your bodies. If you tear out the convector system, you'll literally be spending big money to decrease your comfort level and overall system efficiency. We would NEVER suggest that our customers go this way. With today's and tomorrow's fuel prices, we can't afford to increase our fuel consumption this way, can we?

Now as to the boiler question: First of all, we don't discuss pricing here. This has been a house rule on The Wall since long before I started posting hereon.

Second: will you be increasing the house's thermal efficiency by adding insulation, upgrading windows and doors, etc? If so, you would need a smaller boiler which will burn less fuel year after year, which will have you sitting pretty as fuel costs rise.

Third: has anyone done a heat-loss calculation on the house as it will be when finished? If not, these proposed boilers are just guesses, and are probably oversized. Oversizing boilers is an extremely wasteful practice.

BTW, will you be using oil or gas?

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

Steamhead (in transit)

Well, then

don't even consider a vertical-flue, pin-type boiler. These are much harder to service than the 3-pass type since the flueways are narrow and filled with pins. The cheaper W-M model is probably a WGO, and this is a pin-type. The W-M Ultra Oil is a 3-pass, and would be a better choice. On a 3-pass, all flueways are accessible from the front (and some have rear access too) so they are much easier to keep clean- ask me how I know that ;-)

What you may not be aware of, is that some boilers can be fired with either oil or gas. This would put you in control of what you burn and how much you pay. W-M does not offer this option, but others do.

We like the Solaia boiler which is a slightly massaged Biasi. This boiler can be had from the factory with either oil or gas burners (It's also available as a Dunkirk, PurePro or Utica but I'm not sure if these brands offer the gas option). So there's no field-engineering necessary if you want to change it over. Your heating pro can swap out the burner and a few trim items, set it up with a digital analyzer, and you'll be on the other fuel. Here's a shot of one we installed recently which is gas-fired.

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

Steamhead (in transit)

Well, then

don't even consider a vertical-flue, pin-type boiler. These are much harder to service than the 3-pass type since the flueways are narrow and filled with pins. The cheaper W-M model is probably a WGO, and this is a pin-type. The W-M Ultra Oil is a 3-pass, and would be a better choice. On a 3-pass, all flueways are accessible from the front (and some have rear access too) so they are much easier to keep clean- ask me how I know that ;-)

OK, a modern oil-fired boiler should not soot up at all if properly set up. But if something goes wrong and it does soot up, it should be easy to clean.

What you may not be aware of, is that some boilers can be fired with either oil or gas. This would put you in control of what you burn and how much you pay. W-M does not offer this option, but others do.

We like the Solaia boiler which is a slightly massaged Biasi. This boiler can be had from the factory with either oil or gas burners (It's also available as a Dunkirk, PurePro or Utica but I'm not sure if these brands offer the gas option). So there's no field-engineering necessary if you want to change it over. Your heating pro can swap out the burner and a few trim items, set it up with a digital analyzer, and you'll be on the other fuel.

Here's a shot of one we installed recently which is gas-fired.

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

Robert O'Brien

If

it has to be hydroair,oversize the HW coils to allow use of an ODR control.An ECM would also be my only choice.I would do a heat loss calc, an S-125 is too big by 2X for a typical LI ranch house.

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

Bruce M_2

Get another Opinion

You live on Long Island which is "oil country". There are a lot of competent professionals who could fix your hot water system. There are companies which can detect and fix any leak. Meenan Oil has a long standing expertise in this field because they have been servicing Levitt houses for 60 years. If there is a leak in your current system it is not hard to repipe the system. If you do not install a truly efficient boiler you will be wasting a lot of money.