Whats the difference between residential and small commercial heat/ac units?

[Old Man Kenneth]

Are the commercial units more heavy duty? Built better? Or what and why dont you see more small commercial units in homes?

[hcong]

Are the commercial units more heavy duty? Built better? Or what and why dont you see more small commercial units in homes?

From my experience the light commercial units have more powerful fans, slightly better capacities, outside air intakes, and models that are larger than 5 tons.

The line between light commercial and residential is blurry sometimes, I think it really depends on what system you need. I know several commercial spaces that we put in residential split systems (furnace + coil indoors and condensing unit outdoors). Same with the fact that I haven't seen many packaged rooftop units on houses, but I have designed a few.

Why do you ask?

[Old Man Kenneth]

just wondered really, didnt know that all commercials are roof top mounts

[hcong]

just wondered really, didnt know that all commercials are roof top mounts

Sorry, I didn't mean that all commercial ones are roof mounted. I was just using roof top ones as an example since I don't see many houses (at least in California) that are roof mounted.

[motoguy128]

IF you're comparing split system 5 tons and smaller, the only difference is that the indoor and outdoor units can be purchased with 3 phase power source. Commercial and industrial buildings often use 3 phase, so it's cheaper to purchase equipment that can run on 3 phase rather than needed a larger transformer for a larger single phase panel.

Beyond that, equipment size gets larger and they accommodate larger amounts of fresh air intakes for higher typical indoor occupancy as well as economizers.

Commercial is dominated by package rooftop units or large packaged air handler units (like ones you want into). As you get larger, you usually see chilled water used, first air cooled units, then water cooled with separate cooling towers outdoors. ON the heating size, beyond a certain size, you are usually steam coils which means there is a larger or multiple boilers to produce steam.

IT all comes down to economics. Lower initial costs, vs. lower maintenance costs, installation costs, operating costs and space considerations as well as overall comfort of occupants. Most technologies are tried out first in the commerical size due to their higher costs, then later adapted and make cheap enough for the residential market. Zone controls, inverters. scroll compressors, and so on.

I think it's funny how geothermal (water cooeld heat pumps) are somehow considered new. We have tons of water cooled AC units at my work. One we think dates back to 1959 when one building was constructred. Its' a big green monster than Trane cannot find and info on it's so old. A couple others from the early 80's too. I remember seeing a water cooled unit the other day at what was a old tavern, that had to of been pre WWII. IT had that art deco look to it like early refrigerators.