RF Transmitter Receiver Recommendation?

[markedwards]

But it seems that you need multiple transmitters to avoid running wires up and down the stairs. ?

Yes absolutely!

Can you be a bit more explicit about sensor locations and whether you want continuous or periodic operation?

I was thinking real time data w/ 1 reading per second per each sensor (6 readings per second) would be good

Some systems operating conditions can ramp up and shut down in a matter of seconds others rarely change. I have experienced an intermittent high pressure switch
that caused rubber hoses to ocassionally fail.

I have never had an opportunity to work with radio communication and thought this would be a good project to learn.