Yes if you watch it. The DVR has to load the OnDemand programming to the hard drive, so you can watch it. Also keep in mind that depending on your Internet provider. Will depend on how fast it downloads.
i was asking because i want to download a series and keep it but im in low %20 on my DVR, so that out, 2nd question when does the DVR start delete stuff automatically? because i get that ! alot