Need Date of Lennox Co Furnace (SR? 00 or 01 ?)

I have a photo of the door of a Lennox Company Furnace. Below the name it looks like it’s imprinted with SR? 00 or 01 ?

The furnace front and interior was originally a cast iron, short/squat “pot belly” coal-fired furnace.

Later, a fan and motor were placed beside it in a open top wood-enclosure with hinged door. I presume it was a conversion from convection to forced-air coal.

Later, the furnace was again converted, this time to natural gas.

On one side of the furnace were old ducts wrapped in asbestos paper.

On the other side of the furnace, new (unwrapped) (galvanized steel ?)ducts were placed.

The original ducts went to drop vents located low on walls on the first and second floors. The 2nd floor also has several larger (cold return?) vents in the floors?

A second gas furnace was installed about 1940 for the first floor, with heat registers and cold air returns, both in the floors of each room (1st floor only). It’s ducts to the top edge of floor ducts have only asbestos wrapping, which is crumbling at edges.

The Lennox furnace was in a home built between 1890 and 1900 in NE Ohio by a rich leather-works owner. The home is 1/2 block long and roughly 1300 sq feet per (3 floors counting unheated attic). The 2 floors of living space have 3 fireplaces (since converted to gas but now blocked and unused for years); the 2nd floor was heated by the Lennox; the first floor has been heated by the 1940s furnace.

I figure they used only a straight convection furnace at first for the whole house, then converted / upgraded. The converted-to-gas Lennox–originally coal–furnace was in operation until 2007. It was only replaced after the pilot light, which was hard to re-light (inside the old bottom door used to clean out coal ashes), kept going out.

I have pictures of the Lennox furnace showing the front, sides, and both types of ductwork. But since I’m new here, I’m not allowed to post them. If anyone wants I can send the pictures by email. The lettering on the door is mostly clear.

I wanted to know what the 2 letters mean on the right side of the door, under the company name. If it is SR as I think it is, what does that stand for? Is the 00? or 01 ? numbers (across from the SR) on the right indicate the year of manufacture?

I read that natural gas furnaces started around 1935. Is there a way to find out the age of the 2nd gas furnace that’s still in the home-- I was told it’s a 1940s one. Is there a place to look for a Model or Mfg date?

As a secondary question, health-wise, what are the risks when asbestos wrap begins to deteriorate and crumble from wrapped ductwork and at the inside edges of heating vents? I’ve lived here about 14 years and during this time some old vents have split at points of seaming where one length of single duct meets another length (and so on), because of the weight created by using several “one long duct” placements through the basement from almost the front house wall to almost the back house wall, and too few original hanger or wire supports. Each extra long seamed-duct travels maybe 50 to 60 feet from front to back. Several sections separated entirely over several years; These seam breaks with torn asbestos covering at the seams were then repaired NON-professionally (i.e. duct tape and poorly rigged rope-support done by landlord). Other ducts have not broken at seams, but the covering on all the old ducts have crumbling edges along every wrapped-turn (the layers overlap each other at an angle and those edges are the worst). With all the news about asbestos exposure, I’m wondering if those breaks in the coverings pose health risks. Is the risk only if the broken covering is handled? Or once broken, are there airborne particles that pose a risk?

Thank you,


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