Equipment uses half the amperage when run at 220/240 compared to 110/120. It has nothing to do with cost.
Your right, and I see your point
but,
It takes up twice the breaker space! Where's your benefit in that? If the box is less then 200 amps. He's already pushing the space in it. Most I've seen/worked on were less and had space available for 2 30amps but, with 2 set already (30's) and 3-4 20's (bathroom and kitchen) and 15's in the rest of the house. The available breaker space is almost gone.
If, you have that 200 amp box. Now you
may have space for some. Even then the average
in home box has 20 available breaker spaces. Now then Run a well? 30 amp - 2 spaces. Electric stove ability is in most homes 50 amp - 2 spaces. 3 bedroom 3 15 amp outlets 3 spaces. Bathroom - dedicated 20 amp GFI and a none GFI 15 2 spaces. Kitchen 2 20 amp GFI's and a 15 for 2 other outlets 3 spaces. Basement/laundry room 30 amp 2 spaces. The rest depends on outlets available. Say 2 15's for the basement and 1 for the laundry room so 3 total there.
Garage will take at least 1 space... So in total, we are damn close to a full box..... Many will combine a few of the bed rooms, and maybe a kitchen to the garage, laundry thrown on another low use line, so give back 3........Generally I see 14-16 spaces filled on an 20 box..... Not many
homes with 30+ space box's...
This has to be a newer home too. Cities have plenty of box's under 200 amp. Not like folks are running to spend money to change over to the new home code. Fair share of Federal Pacific and Zinsco panels (Many period GE-Sylvania panels are Zinsco made and need to be replaced) still in homes from the 50's to the 80's. These are dangerous and need to be replaced if you have them!
Then you still have homes over 40 years old with split-bus panels.
Not to long ago I saw a
fuse box in a city home that someone wanted help with. That turned into a big money change over for the guy (I told him to get a free panel from the electric company. The electrician bought one and charged him extra).
The other thing is. Unless your growing rather short plants. A DE is not the best in home idea. No high ceilings to draw the heat up and away. 2-3 ft from canopy to light...... I would want a
minimum of 12 ft, floor to ceiling, to run a DE for short plants.
More would be much better! Like 16 to start with.
See mine?