If your ENGINE can't keep up with a larger alternator, how do you expect it
to keep up with the load you want that exceeds the capacity of the
alternator you already have?

If you plan an electric load that is larger than the alternator, then you
have to either enlarge the alternator or reduce the load. You are not going
to reduce the load by changing the lights. The lights (headlamps excluded)
only draw a few amps. Divide the total wattage of the lamps you will be
changing by 12 to determine that amps you will save.

What load are you planning to add that will cause you to exceed the
alternator's capacity?

This is one of those things where you have to decide between fuel mileage
and comfort -- assuming the new load is a comfort-based load.

 And you'll spend a small fortune doing it - some of those LED
conversion lamps are north of %50 each.  The payback will take forever
- they're only practical for high-vibration uses like unsprung utility
trailers where regular lightbulbs get bounced to death.

 Adding a larger alternator of the same type you have now is easy -
they use the same frame size for anything from a 60A to a 90A or 100A
unit, and the wiring will plug in just the same.  The only hard part
is putting in a larger charge wire from the alternator output stud
back to the battery, to handle all the extra amps you are making.

 Go find a good local Auto Electric rebuilding shop - they can look
at what you have, tell you what it puts out now, and what they can fit
in that puts out a lot more.

 The EFI Computer can easily bump the idle speed up to cope with
spinning a bigger alternator.

 Another stop-gap trick is to get a smaller pulley for the alternator
- you overdrive it so it spins faster and puts out more power at idle.
But be warned, if you change the pulley and you like taking the car up
to redline regularly you can overspeed the alternator and make lots of
shrapnel out of it...

 If this is a simple HEPA and Carbon Filter, there is just a fan
motor pushing the air through, and that's your main power sucker.  You
can get a 12-volt motor to run the fan directly, the hard part is the
mounting and shaft length and diameter to mount the right fan blade.
Or you take the factory fan out and use a small 12V radiator fan
motor.

 If it has an electrostatic capture grid, there is a high voltage low
current power supply to get 10KV - 25KV DC at a few milliamps.  For
that, you go find a power supply that will go straight from 12VDC to
25KVDC, and save the losses in the 120VAC conversion step.

 Ozone generators are just a High Voltage Power Supply and a set of
static transfer spikes to charge the air.  They don't do much, and
Ozone is rather corrosive in any great quantity.

   --<< Bruce >>--

The Austin Air HM200 is recommended for areas up to 700 SF and has a
capacity of 200 CFM.  If the 700 SF room has 8 foot high ceilings, the room
has 5600 cubic feet.  At 200 CFM, it theoretically takes 28 minutes for a
complete air change in the room.

A Corolla wagon has interior volume in the neighborhood of 120 to 150 Cu.
Ft.  At 200 CFM, your purifier can do a complete air change in less than a
minute, which sounds like overkill to me.

Assuming 150 Cu. Ft. of air in the Corolla, a 10 CFM fan would change the
air every 15 minutes, still faster than the Austin Air HM200 is designed
for.

Does your filter use electricity only to circulate air past the filter
media?  If it does, perhaps you can fabricate a shroud that fits over the
filter's air intake with a 12V fan that moves air into the shroud, kind of
like a kitchen oven's hood that moves air in reverse.  The shroud would
avoid messing with the filter itself and potentially ruining it, and being
able to move air through the filter would give you the advantages of the
nice filter without the big power draw.

ozone is also bad for the plastic and rubber in the car.

I like to buy stuff that I can see and touch firsthand, not just on a
screen.  If I could, I would take the gadget apart and put it back together
before buying it.   ;-)