Hashrate distribution went from 4.4% to 0.6% in the last 4 days, looks like a large factory went online in china.
https://blockchain.info/pools?timespan=4days

They either have a limit of 1 per customer or inventory of 1.  When I try to add 2 to my cart it says unavailable.  I might drive there on my way from work.

I think that you would probably not want more than (3) 50 amp 240 volt circuits drawing continuous power at your house.  3 50 amp circuits will allow 18 Antminer S9s drawing a total of 100 amps.  That will allow you 100 amps for other items around your house.  I don't know what your additional loads are at the house but you probably have additional 240 volt circuits for things like air conditioner, dryer, oven, hot tub, etc.  An electrician can do a quick load calculation to let you know if you can draw 100 amps continuously and allow for normal operation of your other appliances and electronic equipment.  30 S9s would be 165 amps, (30 x 5.5), and you wouldn't have enough power at a house to run normally.  If you think you are going to run 30+ I would look to get a space that has at least 400 amp service and 3 phase power.

I would really want you to verify that you have 240 v and not 208 v at your house before proceeding.  I believe (and Finksy or others can correct me if I am wrong) that the PDU can only handle 12A per switched port and is rated for 40A total power.  The 2880 watt PSU is capable of powering 2 Antminer S9s but only if you have 240 volt power because if you have 208 volts then you are drawing 12.6 A to power 2 Antminers, which may be too much for each port of the PDU.  The "pimp daddy" package will allow you to run 6 Antminer S9s from a 50 amp 240 volt circuit using 3 ports of the PDU, I think in theory you could add a single Antminer to the 4th port, but I wouldn't do it.  Assuming 240 volt power and Antminer S9 13.5 THs I would only run a total of 6 miners on each 50 amp dedicated circuit and a total of 4 on a dedicated 30 amp circuit.  I hope I answered your question.

1) I have one S9 in my basement venting outside, the rest are in other garages.  So I can't speak much for the sound, I can just tell you that the hotter they get, the more sound you will hear.  The startup sound is extremely loud, but it will slow down once startup checks are done.

2)  If you put it in a room you will definitely want to vent it outside; running an air conditioner to cool is like running an additional miner because of the additional electricity costs, so you have to keep that mind.

I have no idea how to quote a comment so please forgive me.  I am also not the best at electrical but I can tell you what I've learned and if someone wants to correct me, that would be great. 

200 amp 120/240 single phase service is probably common for a house, my house is 200 amp 120/208 single phase. 

I started with 1 miner about a month ago, plugged it into a 120v 20amp dedicated circuit and exhausted it through the basement window.

The only reason that I mentioned voltage is because your miners will draw different amps depending on the voltage.  As an example, the Antminer S9 is pulling 1323 watts from the wall.  The calculation is V x A = Watts, so to figure out amps, just divide watts by the voltage.  So, on a 120 volt circuit, it will pull ~11 amps.  That same miner connected to a 240 volt circuit will pull ~5.5 amps.  The miners are also continuously running so per NEC you have to derate the power by .8.  So as an example, a 50 amp circuit x .8 is = 40 amps.  I'm running 6 miners on a 50 amp 240 volt circuit so my miners are drawing 6 x 5.5 = 33 amps which is well below the NEC recommended 40 amps.  My PDU is also rated at 40 amps, so I am well under what that is rated as well.  If I was to plug that same 40 amp PDU into a 30 amp 240 volt circuit I would not run more than 4 S9s on that.  That would draw ~22amps, 80% of 30 = 24amps, so I am safely below the guidelines for that as well.

At this point, I am investing into miners.  I should have invested into bitcoin for the last month, but I didn't .  I have a larger project in mind that I talk about here: https://bitcointalk.org/index.php?topic=1920614.0

Make sure that your 240 V is really 240 V; at my house I have 120/208, so I am just running 2 13.5 THS S9 Antminers each on a separate 20 amp 120 v circuit, each with a 1600 watt power supply.  I am also running 6 S9 Antminers on a 50 amp 240 V oven circuit from a 40 amp PDU, I believe the miners are pulling around 5.5 A each.  On a 208 circuit the miners will pull 6.3 A.  The three car garage where I have 6 miners in gets really warm during the day, so you have to really think about ventilation.  Finksy sells power kits for bitcoin miners, I would highly recommend his equipment. There is a thread from him here https://bitcointalk.org/index.php?topic=966135.0.  I did not see on the Bitmain site where T9 is for sale currently, maybe I missed it.  The S9 is sold out and won't be shipping until July 5th.  I have 13 more S9s coming in Friday, just waiting on the electrician to install (2) 3 phase 60 amp circuits at the shop.  If he doesn't do it soon, I may sell these S9s and order more from the July 5th batch.  

Thank you for all the replies and feedback so far.

The electrical upgrade on the building was an idea prior to me getting involved in bitcoin, it makes financial sense as an investment for the long-term marketability of the building.  Also, I'm not using the entire building in my main business so I do have space for racks, shelves or even purpose-built data rooms.  The one thing I don't have now is power, just 200 amp 3 phase 208 at the moment.

I do not know the power factor that is to be taken into account so if someone wants to clarify that, please do.  Also, my numbers below do not take into account ventilation and/or cooling costs, just the bitcoin miners themselves.

The meter charge is $66.17
Demand is              $  8.00 per kW
Energy is                $0.10629 per kWh

An an example, running 1 Antminer S9 13.5 TH/s for 1 month.  1.323 kW x 24 h x 30 d = ~953 kWh per month x .10629 = $101.29 + $10.58 demand + $66.17 meter = $178.04 = eff rate of $0.1868
another example, running 100 Antminer S9's 13.5 TH/s 1 month.  1.323 kW x 24 h x 30 d x 100 = 95,256 kWh per month x .10629 = $10,125 power + $1,058 demand + 66.17 = $11,249.17 / 95,256 kWh = eff rate of $0.11809

I know I am paying more per kW than a lot of other places, but for California my rates are really low.  I do have the benefit of close proximity and full control of the miners, also I'm not paying rent for the miners as well because the space is already there.  If anyone has any comments or corrections on my calculations please let me know.

I forgot to mention that I am also the building owner, so upgrading makes sense even without crypto mining.  Light industrial buildings in my city are at a premium because of the lower power rates compared to PG&E; lots of machine shops on my block.  I'm hoping that the city will provide wye service from their side when they perform the upgrade (city owns the utility).  I'm sure it will be 5-6 months before permitting is complete, so it will be a long process.  In the mean time I'll have (2) 3 phase 60 amp dedicated outlets installed next week to run 24 S9's.  The electrician mentioned something about a transformer probably to deal with the Delta service.  I'll have 1 18.7kW PDU per outlet and 12 PSU's driving 12 S9's.  I'm not sure if I can run more on there, but I think I could push it up to 14 per circuit.  Electricity isn't my forte, just trying to learn more about it.

The existing city transformers are at capacity so they have to install new transformers on their end to service the building if I upgrade to 800 amp service.  I'm hoping that they can put in wye service at this point and then I can rewire the building internally.  My cost to the city for 800 amp service is $21,000.  After getting an electrical engineer and electrician for connection and distribution I'm probably looking at $75,000 for the project.

Thank you very much for the feedback, really appreciate it.  It makes sense that there is Delta service there, it's a light industrial building with office space.  I'm trying to get 120/208 800 amp service there so that I can run a few more miners, but with permitting and city approval that will take probably until the end of the year.  Tesla is the man, too bad Edison tried so hard to discredit him.

I've got a question regarding Delta vs WYE 3 Phase service.  

If I understand WYE correctly with 200amp 120/208 service, that would give me 208V x 200A x 1.732 = ~72kW available power.  Each hot leg would be 120V x 200A = 24kW x3 legs = 72kW.

Can someone tell me how that equation works out for Delta service?  I have 240 volts between each of the phases, 120 volts to ground on 2 legs, and 208 volts to ground on 1 leg.  Is the equation 120V x 200A x 2 + 208V x 200A? That equals 48kW + 41.6kW = 89.6kW when adding the phases separately?  How does that translate to 3 phases when trying to calculate total kW?

Unfortunately the building where I'm at has Delta 3 Phase so I'm trying to understand how much power is available with that service.

I appreciate any feedback and/or corrections of my calculations.

The Los Gatos Blvd address is supposedly their office address.  I live 15 minutes away from that address, but wouldn't really know what to look for once I was in.  They could show me something that is all smoke and mirrors and I wouldn't know any better.  Maybe ask them to mine for you for 12 hours and then you can look at your pool page to see the result, that might be a way to show their system is working.