I am so confused. We have two estimates we are considering- one it three ton for 2300 well shaded house, other 31/2. One guy will use 3/12 coil with three ton , other guy says they need ot match. One vents to floor drain , one to sump. One says humidifier can't use furnace condensate pump, it will be clogged with mineral deposits. ONe is offereing a bypass humidifier others says use power humidifier with multispeed furance. Both are premeier Lennox dealers

First question,why lennox?
The evaporater coil should match the condenser
Next the humidifier puts water/moisture into the supply system,doesn`t take moisture out so why does it need a floor drain or the furnace condensate pump

I think you need to get more estimates from other companies with referances on the quality of equipment and installation
It may not be the same in your area but around here Lennox is not popular because when parts are needed knowone has them in stock and parts have to be ordered and takes several extra days to get repair done

I agree... you need more proposals... several things you mention don't make sense...

We got 8 estimates. Supply company says that bigger coil can increase efficieny doesn't need to match. Lennox is name brand here, also looked t Ruud and american standard

I've always been told that unit size + 1/2 ton on the evap coil was limit?. ie... 3 ton unit = 3 1/2 ton max on eavp coil... o'course... I don't know... just what I've been told for years... and I've been building houses for 40 years...

A larger coil does increase efficiency by providing more coil surface for heat exchange.

next... humidifiers that I've seen didn't have a drain line... they have a supply line because they put moisture "in" the air... a dehumidifier has a drain line...

Why humidifier ? Do you live in dry climate ? Here in the south we need a dehumidifier.

why does the furnace have a drain line ? Is it in a basement ? Mine is a high efficiency (with evacuation fan) and does potentially create a small amount of condensate in the flue but the flue is installed with a slight down hill pitch so (if condensate does occur) it will gravity drain to the outside. Only an issue in extremely cold weather anyway.

I guess... pick the contractor you feel best about and make sure they will be there later to make sure you're pleased with the results?? Be sure to keep all paper work and warranties... you may need later...

Had a thought!. I wouldn't initially install a humidifier nor dehumidifier... get the new system installed... use it a while and see what (if either) you need... if you do... purchase a separate unit independent of the main house system... That's what I did... Works great!. just a thought ?

If mildew is a problem... get dehumidifier

If shrinking wood, dry sinuses... get humidifier

Ive never seen a 90+ furnace without a condensate drain, what brand do you have spanky917?
Ive also never seen a humidifier without a drain(that doesn't mean they aren't out there, just never seen on a forced air furnace). The ones we install have water supply that runs water over a humidifier filter(or pad) and then the excess water goes down a drain hose to either a floor drain or condensate pump etc. We install a lot of humidifiers due to our extremely cold dry winters. I have also been told that you can oversize evap coil one size, but I've also been told a lot of things. Matched system is preferable in my opinion. Good luck with your new system, hope it works trouble free for years to come. Take care.

My a/c evap coil has a drain but not the furnace...

Down here (in Ga) we don't have much use for humidifiers... why wouldn't the humidifiers have a reservoir with float valve and circulating pump instead of just letting the water run over into a drain... sounds wasteful !

I guess equipment in different regions varies greatly...

Humidifiers & dehumidifiers down here are just small independent units sitting in a corner somewhere and they work great... I've got one in my basement now to prevent mildew... cost $75 at Sams... been running for 10 years now

However, you can have one installed in a central unit it's not commonly done... much more costly...