Where are you located? Why only 80% furnace? They both seem pretty high to me. Might want to get more estimates on diff brands (try Trane/Am Std, Rheem/Ruud, Goodman/Amana).

Quote 1 looks like a typo it should be a 24VNA9 this condenser model is a 5 speed variable system. (Inverter System) Pairing a system like this to a zone system is the cat's meow, the hot dog's bark, the cool man's Luke of HVAC systems.

Quote 2 maybe a single speed and I don't see any mention of zoning with this one. If it is single speed it can work with zoning, but it's performance will be no where near that of the inverter system.

You may want to get some other bids Amana inverter system is a bit more efficient at around 21 SEER depending on equipment configuration. Also the Amana manufacturer warranty is hard to beat.

Day & Night isn't in all locations and they may not make an inverter 5 speed system. This realm is typically that of the big national brands.... I know of a few that delve into this area but they are somewhat rare. As a side note Day & Night is more or less a off model Carrier.

Brand aside, installation & system design is most important especially when it comes to zoning and 5 speed AC systems. Above that your relationship with the installing company. So keep these things in mind.

Thank you for your comments. I am located in Los Angeles so rarely need to use the furnace and also probably explains why the quotes are so high, labor is expensive out here! At this point, I am very confused as to what my home needs and am not comfortable with any of the quotes I received. I am going to look into Day & Night. Thank you again.

pdk830, good idea! Again, hvactalk.com!

You can read and ask questions there (from PROS), to better understand your own needs.

For example, zoning can be great, BUT our house is 50 years old, and unless someone could redo a lot of the runs and returns, it wasn't going to work correctly or efficiently. That didn't stop most of the companies from trying to sell it to us though!

IIRC, I first read about the Day & Night brand on someone's blog (an HVAC company) out of San Diego. I'll see if I can find that link for you.

Mary Elizabeth- thank you! I posted on HVACtalk as well.

Quote No. 1 is Carrier's top of the line equipment with an 80% efficiency furnace. The Infinity zone controllers are the best but they are very expensive. The AC condenser model quoted is over kill in my opinion. You don't have to spend this amount of money to get something that will work well.

How large is your home? Are any of these contractors doing a load calculation? You are being quoted 90K BTU furnaces which are too big for your climate. The reason for this is that you are also being quoted 4 ton condensers. If you are near the coast your cooling requirements many not justify such a big AC.

If you like the Carrier and Bryant contractors then ask them to quote other equipment. If you are going to install zoning then I suggest you spend the money on a variable speed furnace and 2-stage condenser.

mike_home- my house is in Los Angeles, 4-5 miles from the beach (as the crow flies) and gets a nice breeze. Note that we have not moved in yet because we are doing renovations so I don't know what the temperature swings are like. It is 2 floors, 2,200 square feet with 2 bedrooms on the first floor and master bedroom + 4th bedroom on the second floor. I would estimate first floor square footage is approximately 1400-1500 sq ft and second floor is 700-800 sq ft. The first floor has a very high (2 stories) vaulted ceiling in the main living room and both bedrooms on 2nd floor also have very high vaulted ceilings.

I don't know if either of them did a load calculation. I would like two zones. Would it be more efficient/cheaper to install two completely different systems, one for each floor?

Two separate systems is going to cost more than a zoned system. Even if you wanted to spend the extra money, a separate system for a 800 sq foot second floor is not practical. A properly installed zoned system would be your best option.

I highly doubt either of these contractors did a load calculation. They are either using the current sizes, or using their rules of thumb based on the square footage of the house. Rules of thumb tend to over size equipment which leads to an uncomfortable house and money wasted.

Try to find at least one contractor who will do a calculation and agree to explain the results. If you are adding new insulation or windows that should be factored into the calculation.

You also have to be careful about choosing a good contractor if you are going to get zoning. Most contractors don't know how to install zoning properly, or they want to cut corners. You can buy the most expensive equipment, but if it is installed incorrectly it will never work properly.

mike_home- what do you think about installing ductless mini split systems in both 2nd floor bedrooms and smaller hvac system on first floor? that should reduce costs meaningfully and be the most efficient, right?

Have you seen the installed cost of mini splits? I doubt it would be cheaper than a standard split system.

If the second floor has an open floor plan, then a mini split might be a good solution. If there are two big rooms and a hallway, then a mini split with two heads might work.

I think the cost will be more expensive than a zoned system. However it might be a way to eliminate the risk of a more complicated zoning installation. I would put it on your list of options to consider.

Day n Night is more or less the same thing as Comfort Maker and Heil. These are all ICP brands that are very similar. In fact if you look at the ICP brands they all look the same except for the name decal on the units. The Carrier Infinity is more or less the same as these just in a different wrapper.

The Day N Night, Comfort Maker & Heil are more or less ICP brands that tend to use a lot of the Old Carrier 'TRA' model number tech transferred over to R410a refrigerant models. These 'TRA' models were used back in the early 2000 time period.

The biggest thing of note that I see in comparison to the Amana 5 speed is the compressor type difference and the noted noises these machines make after each cycle. (Hissing noises).

As far as I can tell the hissing noises are probably related to the type of compressor used for the 5 speed machine as Amana makes no mention of any new noises of operation.

In the 5 speed machines (Inverter Systems) The Carrier and ICP brands all use Rotary Compressors. The Amana uses Swing Compressors in all units up to 4 tons and scroll compressor in 5 Ton model. This is also likely the reason the Amana is a shade more efficient.

Carrier makes model that is more efficient in a 2 speed. However, with that said matching a 5 speed machine with zoning would increase efficiency in my opinion not to mention it will just work better.

If you decide to go with a ICP brand or Carrier 5 speed, due to the hissing noises the condenser will make after every off cycle I would be leery of placing this near a bedroom window.

2 speed models likely won't make these hissing noises as the compressors are almost always scrolls.

I've been to a class on the Comfort Maker 5 speed (Inverter System) and while the hissing noise is not all that loud or lasts that long (few seconds), the noise occurs after every off cycle. Condenser sitting near a bedroom window it would take some getting used to. So you definitely want to consider these things especially tied to a zone system, because equipment cycling can happen a bit more frequently with zone systems.

Interesting - sounds like the old disclaimer on LCD video displays ("white dots on the panel are a normal part of the manufacturing process and do not represent a defect"). Which was, if course BS! I suspect as they get the engineering "issues" figured out, this hissing will be banished. Given the cost of these new inverter system, I'd be pretty pissed if it was hissing like a snake, 24/7, every time the unit turned off!

Yeah and even the Carrier infinity 5 speed has this oddity. As far as I know only Carrier or ICP made 5 speed inverter systems have this odd noise event so I thought it was kind of strange.

Needless to say, if the unit was no where near a bedroom window you probably would be none the wiser unless you happened to be near it when it cycled off.