Describe your typical winter temperatures.

Where will new furnace be located? If you elect high eff furnace, then you must vent normally through an external wall either in basement or crawlspace.

Correct sizing of furnace is important for both comfort and operating cost.

What do you plan to do about asbestos ductwork?

Yes, you need a minimum of one return for each floor . I would think a minimum for 800 CFMS for each return. Of course return should be strategically and centrally located best at internal hallway.

IMO

Just reviewed winter temps for LA.

I would think a high eff furnace 60 K size with ECM blower motor would be adequate. AC could be added at a later date if ever interested.

IMO

Thanks for the reply!

Re: Asbestos ductwork, we want it out. In all honesty, if we didn't have the asbestos, we would probably live with the gravity heater for a while--removing this is the main reason the heating system is even on our radar.

With regard to the duct location, is it okay to keep them on floor on interior wall? Some things I read said that this was not correct, but the first person who came to visit our house said it was fine. I am sure that changing the location will add more cost to the installation, but I would like to know if there is a big difference in the comfort level or use of energy if they remain where they are located.

If the asbestos covering is intact and not shedding any fibers then it is safe. There is no need to spend money on removing it if the current heating plant is working well.

The duct work for a gravity system is very different from a forced air system. You are going to need to duct modifications if you get a new furnace. At that point the asbestos will have to be removed. If there is not a lot then you could remove it yourself and save a lot of money.

Normally floor registers are installed on exterior walls below windows. The idea is the cool air coming from the window drops to the floor and causes a draft. This makes the room uncomfortable. The warm air rising from the registers helps to counteract this. I would not spend a lot of money to move the registers. It is not worth it in my opinion.

On ductwork, normally supply registers are located on external walls and return(s) on internal walls.

So you will have all old ductwork removed. I would ask dealer what his recommendation is. I am not sure if I would go to the trouble and of course the expense to change location of supply registers. You do need at the very least one return on each floor. I would want R8 insulated ductwork.

Post back and let me know what he says.

IMO

I will follow up with the one fellow that we have gotten a quote from. He was highly recommended as doing a good job, but in speaking with him I wasn't sure--as he seemed to answer my questions counter to what I had learned thus far online (e.g. only 1 return register needed; location of supply registers fine--and I don't think he did a cost-benefit analysis, I think he didn't even think about it). Because he WAS highly recommended, I wanted to give him the benefit of the doubt and see if I was misunderstanding what I read. Seems like I was not. I will need to get some more quotes, but likely cannot until next weekend, unfortunately.

Is the heating installer usually the one that insulates the ductwork, or do you mean that the ducts themselves are purchased with R8 insulation?

Also, the machine he recommended was the York Guardian model# GG9S080B16MP11 (95% efficiency). This seems to be an alright model--not excellent. Do you think this is appropriate for a long-term fix? I would be willing to spend more on the model if it means it would last substantially longer and with fewer headaches.

Forgot to mention--it will be located in the basement.

Also, I am okay with the asbestos ductwork for now, but my husband is adamant about getting it out, so I am trying to do some research and figure out what the appropriate new installation should look like.

"I would think a high eff furnace 60 K size with ECM blower motor would be adequate. AC could be added at a later date if ever interested."

You certainly don't need an 80 K size high eff furnace. Not a particular fan of York. I will review this model later when I have time.

IMO

Duct work in the basement or any conditioned space does not have to be insulated.

Keep asking questions of HVAC contractors. Most people call it getting quotes. I think of it as interviewing someone for a job. If they can't answer the questions to your satisfaction then the price does not matter.

Not all basements are conditioned.

IMO

The Guardian is a low end furnace. I wouldn't have it. Not clear of York connection.

York Guardian 80,000 BTU 1 Stage 95% Efficient Multiposition Gas Furnace
by Guardian
Be the first to review this item
Price: $995.00
Only 9 left in stock.
Ships from and sold by Shurail HVAC.
York Guardian 80,000 BTU 1 Stage 95% 4 Ton Multiposition Gas Furnace
1 stage multi-speed multiposition (upflow.downflow, horizontal) natural gas furnace. 4 ton drive.
Dimensions 33H x 21W x 29 1/2D

Planning to meet with more HVAC reps this weekend....