Lowes and Home Depot? Why have you not got Quotes from a proper A/C company?

That's like asking them to put a new roof on your house when you should be using a roofing company.

These prices seem high given the SL280NV furnace has an 80% efficiency rating. But you are being quoted about $5000 in duct work, electrical wiring, and permits. That and the your location in Los Angeles may mean the quotes are what they should be for your location and installation.

First advice is to avoid buying HVAC equipment through a big box store. You are paying more and the contractor is making less profit. Get a quote from a Lennox dealer to compare prices. Your quote also needs to specify the model numbers of every piece of equipment. The model number will indicate the size which is important. You don't want equipment that is either or too big or too small.

A Merv 8 filter is fine, a MERV 11 is more restrictive. Ideally a 4 inch media filter is installed. They are more expensive but last 6-12 months and provide better air flow. You don't need to spend money on UV lights. The thermostat needs to be able to control a 2-stage or variable speed equipment. The fact the thermostat is being quoted lends me to believe it will be low end type and not appropriate for the equipment you are buying. You have to decide whether you want to pay extra for the WiFi type.

You should also understand the warranty coverage for parts and labor. Find out if you are eligible for any manufacturer, local utility, or state rebates.

I'm a little confused - why do you need new ductwork/electrical at all?

Agree with the above though; nix the bigbox stores and find a proper HVAC contractor.

Thanks all, I edited the post to clarify some items. These were both from Lennox Dealers, I got their names through the Home Depot/Lowes pro-referral program.

I added the model numbers, not that they mean anything to me! (eekkk)

A few clarifications: They said we needed electrical as our current electrical is basically untraceable. They cannot find a switch for the AC on the main circuit box. And duct work, again, I have no idea what it means to even need this so we're running blind here - they said our duct work was recent but not done well. For reference, the heat works fine and the AC worked fine until it didn't and no no one can help us even figure out why the unit isn't getting power.

It seems odd 4 electricians can't trace the power from the condenser back to where it's piggybacked onto some other circuit. My guess is that is why the AC is not working.

What kind of ducting exists? An attic unit with flexible runs to rooms? Returns in each room or 1 main one? So is the ductwork to replace all, or just at the unit and it's plenum?

The outdoor design temperatures for Los Angeles for summer and winter are 40F and 89F degrees. It seems a 80K furnace even at 80% efficiency and a 4 ton AC are over sized. They most likely are going by the existing sizes. Does Los Angeles require a load calculation to determine the correct sizes of the equipment?

Home Depot and Lowes sign up local dealers for each store. It seems now the deal is with Lennox. In the past it was Rheem. The one you get could be very good. Good HVAC companies don't have to pay money to big box stores to attract business. The only advantage of the big box store is a financing deal through their credit card, and you have the weight of Home Depot or Lowes behind you if there is a problem.

Another thing to add to your list of questions is what coil will be installed and will the line set be replaced.

I suspect the “duct work” is the contractors profit and cushion.

in the old days, when buying a car, there was $200+ of dealers prep charges.

The duct work charge is equivalent of “dealers prep charges”.

It is not wrong, if a company does not make a profit, it will not stay in business.

It is possible the duct work needs to be repaired or replaced. Post some photos of the areas which the contractors think are a problem.

I wouldn’t ask Lowe’s to replace my HVAC nor would I ask Lowe’s to recommend a contractor to me. Why would I want a third party (Lowe’s) to stick their hand in my pocket too?

“No one can help us even figure out why the unit isn't getting power.“ If the existing unit worked fine until it didn’t, and you know that the problem is that it isn’t receiving power, why not cap off the old electric wiring to the unit and put a new electrical circuit to the old unit? If that doesn’t fix it, then you already have the electrical for a new unit.

As other have said, get a few quotes from unaffiliated HVAC contractors. You're paying extra for the commission the big box stores earn for the referral and you're getting nothing for the extra cost.

Thanks all. We just called in 2 unaffiliated contractors and will see what they come up with. I'll circle back with the new quotes.

Updated update: The installation passed permit inspections and HERS test without new ductwork. All in all the two companies who first quoted us added close to $9K of extra charges that were just unnecessary. thanks again to all of you for your help.

What equipment did you end up installing?

Furnace: Lennox SL280NV [SL280UH080NV48B, indoor coil]

Air Conditioner: Lennox 16ACX [2 stage operation 60%/100%] [16ACX-048-230]

All in including new electrical (our outlet was not to code) and new copper piping (as we wanted it moved) for over 200 feet of wring the cost was $12,400 including inspections and permits.

"An informed customer is the HVAC industries worst enemy"!

Shop around more. I try to get at least 5 quotes. 15-19K seems a tad high to me. Why not just fix what can be fixed and replace what needs to be replaced. Isn't that wasteful to scrap everything. Ultra high efficiency might not even pay for itself over 10 yr period with these low energy prices.... Find more tips on hvacguides101.com