Is that what you use? I know you could run a small Fortune 1000 company from your house
Shamefully, I have to admit that my "rack" consists of about 14u worth of equipment stacked on top of three cabinets in my garage. I do have a plan to get it properly racked & stacked, but life has had other priorities recently...
And yes - that plan does include using a 4-post open rack. I gave each of the server chassis some "quieting" treatment when they were constructed and each runs reasonably quiet. Each of them uses careful cable management to avoid blocking airflow, low noise fans, quiet PSUs, quiet CPU coolers, etc. On the Norco 4220, I made my own 120mm fan tray and pretty made sure there were no un-filled gaps that would allow reverse airflow between the back and front half of the case, which allows use of quiet fans with enough airflow to cool all 24 drives even when it gets hot in the summer (at least i think it will - we haven't really had a hot summer for the last two years). Individually, I could run any one of them in my family room with no complaints from the wife. In fact, at various points in their construction/testing I did exactly that and didn't consider them "done" until I could leave them powered on without the wife or kids complaining. Don't know if the entire stack running together would be that quiet, but in the garage its no problem.
The only troublesome item is the Juniper switch, which even at its quietest fan speed is still too loud. Not obnoxious, but not suitable for living space either.