On Fri, 6 Sep 2019 15:00:15 -0700 (PDT), trader_4
wrote:

On Friday, September 6, 2019 at 5:04:38 PM UTC-4, Davej wrote:
Why the heck would you need a variable speed blower? That doesn't
even make any sense to me. I was pricing a new system until I
noticed that your only choice was a variable-speed blower unit,
which of course bumps the price up.

Idk why variable speed blower would be your only option. One thing pushing towards that is the quest for energy efficiency. An ECM motor is more efficient and when you have that your a good ways toward variable speed. Variable speed let's it spool up and down very quietly. It is also useful with two stage furnace or AC. Downside is if it fails they cost a lot more than a regular motor. I have one, 8 years now, no problem, lower electric bill. On the other hand the ECM fan motor on the condenser failed. It was 350 for a new one, so for 90 switched to a regular, split-phase one.

If you have a variable speed air handler and the or board motor goes,
plan on $1600 plus labor (based on a Trane TWE) because they like to
replace the board and card as a set. The guys say if one is blowing
the other, you will end up doing both anyway after you buy one.
I went the $300 route and had him put in a contactor and a regular
motor. (parts and labor). The couple bucks a month I may be spending
will go a long way before I spend $1750 ($1600 parts, $150 labor)