Pricing varies by region, but no one is going to be able to comment on the price without knowing the model numbers of the equipment. You don't have a valid quote until you have the model number details.

I don't care for a contractor who says you have 3 days to sign a contract otherwise the price goes up $2000. This is a high pressure sales tactic. I would pass on this contractor.

You may need a 5 ton AC, but I would like to see a load calculation to confirm this. I think the furnace is oversized considering your mild winters.

I am skeptical of UV lights. I would not spend the money on this. I would get a 4 inch media filter instead of an electronic air cleaner.

Thank you for the advice.

I did not like the high pressure sales tactic either. That is usually enough to make me ignore the rest of the sales pitch.

I will remember to get actual model numbers next time I have a contractor out to discuss it.

"I also got a stand alone quote for UV...my youngest child has health problems and was told it is used in hospitals etc. for air quality.
$700 for UV installation only"

UV in AHU for commercial and industrial systems has been shown to work when installed properly. I have not seen similar data for residential systems. That does not mean that it does not exist.

rather than putting money into uv lights
put the money into sealing ductwork & return air.

if the stuff the uv addresses has no entry into
the duct system, then there is no use for it.

sealing the system & using 4" pleated media filters
is a better option.
no bulbs to replace yearly, and duct sealing will
last, when properly done for the life of the
duct system.

electrostatic filters aren't an upgrade IMO.
media filter is better investment.

instead of changing r/a filter rack, price
filters like the one in attached picture.
these filters retrofit into existing filter
racks. 1" lip on these filters make these
filters work in existing r/a filter grills.
I purchase mine directly from hvac supply
by the case.

best of luck

Wow very detailed advice thank you.

As a follow up what is the general cost of sealing duct work? We had a free inspection from our AC maintenance company due to air flow and temperature balance and their expert said it wasn't worth the expense to try and fix airflow problems to a downstairs bedroom b/c the ducts run between the upper/lower floors and everything would have to be torn out and redone.

He didn't tell me an actual price though. If it would make a major difference when an entire system is insalled it might be worth considering though.

The draw to me was the wash/reuse of the electrostatic filter. Was quoted annual replacement costs for the 5" pleat type filters. But if I can do it myself like the normal thin filters we currently have it may be worth the upgrade for quality.

fyi:
always get at least 3 bids.
the bids should include model numbers
so that you can compare same size & efficiency
units to same size & efficiency units.

don't let any company bully you into accepting
their bid.

you posted:
We had a free inspection from our AC maintenance company due to air flow and temperature balance and their expert said it wasn't worth the expense to try and fix airflow problems to a downstairs bedroom b/c the ducts run between the upper/lower floors and everything would have to be torn out and redone.

free inspection is worth what you paid for it.
if it is difficult to seal ducts and or address air flow
issues..then everything would have to be torn out and redone.

often air flow issues can be solved by adding manual dampers at the plenum. by adjusting the air flow..
less to some rooms, more to others..this can solve
some of the issues.
this is a different thing than just closing off supply
registers, when you adjust the air flow at the plenum..
where the ducts are connected..then you are re-distributing
the total air flow..not just choking it off at its delivery point.

if you have major air flow issues..then flow hoods
and duct sizing & design may be needed.

costs vary on duct sealing. it isn't rocket science,
but it is a cramped often dirty job. materials are
cheap..but its labor to install.

when in between heating & cooling seasons hvac
companies are more willing to do these type
jobs..as opposed as to full on heating or cooling
season. better rates, better temps to work in.

where is the supply plenum? attic?
what type ducts? flex or hard pipe?
could you post pictures?

while you can't get between floors, sealing where ducts
exit the plenum (and plenum connections to equipment)
helps to minimize leakage. if the ducts are flex..all
the better. flex leaks at either end..not anywhere else
unless the duct is torn.
sealing at supply plenum and again where the duct ties to the supply box will reduce leakage.

the next leakage site is where the supply box
penetrates into the living space.
often this cut into the sheetrock ceiling (for example)
is oversized. as it is hidden by the supply grill,
hvac companies don't often address this leakage.

what I find is that this supply box is surrounded
by insulation on attic floor. where the cut is
oversized, insulation particles & attic temps
condensate on supply grill to interior of house.
sealing this area also addresses leakage,
and reduces insulation particles entering the house.

I use a mastic tape to seal the supply boxes to
the sheetrock. attached is a picture of how it looks
when finished. (hardcast #1402 brand mastic tape is
the only product I use aside from paint on mastics)
remove supply grill. cut mastic tape lengthwise into
1 1/2" wide strips (tape is 3" wide) cut lenghts to
size of supply box. place tape on sheetrock & fold
into supply box. press well to seal. keep tape on
sheetrock within area covered by supply grill.
surfaces will need to be both clean and dry for
tape to adhere.
not only will this seal oversized cut, but it will
keep box flat on attic floor when supply grill
is installed.

you can also seal bath fans with same method above
by removing cover & using mastic tape. both
supply boxes & bath fans are leaks I commonly find
when testing ducts for leaks and houses for air
infiltration. as they are both surrounded on attic
floor by insulation..you understand why it is
important to stop the air leakage.

you can purchase hardcast 1402 at hvac supply
or directly from hardcast's site.

if you post pics of supply plenum, include
return plenum and return inside house.
if you open the return and take a picture inside
of r/a it will help to determine how to seal these
areas.

if you are halfway handy..I can walk you through
how to seal some of these areas. some of the sealing
work can be done from inside your home.
other work would have to be from inside attic or
wherever equipment is located.

best of luck

when you get bids
ask each company to bid for brands they install.
for instance Trane has alt brand American Standard.
same mfg different name tag.
usually cheaper price.

if you have long cooling season, move up to
15-17 SEER a/c.
I find a good roi on these efficiencies
going higher 18-21..not so much.

5 tons on 2400 sq ft is rule of thumb sizing.
investing in a load calculation is a good idea
to avoid oversizing of equipment.

With regard to U/V lights: in a hospital situation, the room air is being 'bombarded' with the light as the dust/particulates waft about. In a ducted system, the airflow is traveling by the light at (hopefully) hundreds of feet per second.

V

Thank you so much for the detailed responses.

I feel like I am taking beginner classes in HVAC.

Unfortunately I am not handy...I'm more of a patent law guy for computer stuff.

I will try and look into the areas you suggested.

Long cooling season is definitely us. Work from home so the AC is running non-stop. Will make sure to focus on the correct SEER range.

Think of each increased point of SEER being something like a 4% reduction in your electrical usage. The cost of going up each point increases but the reduction in your power bill remains the same. The sweet point is around 15SEER. Continuing higher costs more and therefore a longer ROI.

But you're in CA which has high daytime electric rates. This might mean that you could afford to go higher in SEER. Also, you should check with the power company and see if they have any incentive rebates.