Denied to right to property?

Yep, possibly yep, possibly nope.

It falls under exigent circumstances. The evidence (if there was any) had a very, very good chance to disappear if the police did not seize the dorm room. Hence there is justification in the locking.

As for the speed at which they got the warrant, that might fall into reasonableness unless there are specific rules in NH (e. g. a 24-hour thing or whatever). You also don't say whether the 2 days falls over a weekend or anything of the sort. While it's troublesome that the students were locked out of the dorm room for a coupla days, there can be allowances made for diligence by the police/whatever the bureaucratic standard is. But sometimes that can be decided the other way (see cases where governments have been made to comply with various speed requirements, such as for correcting a hazard or complying with the equity remedy of specific performance, even if it's not possible for a government to do so, due to budgetary reasons or others). So the answer is hazy unless more facts are presented. Was due diligence present? What hours are we talking about? If the school is in Manchester, and so are the courts or the JP or Magistrate (or whoever handles warrants in NH), then not a lot of time should be allowed for the cops to get the warrant. But if the school is way up by the Canadian border and not close to any courts, etc. at all, there probably will be some allowances for travel time, etc.

Denied right to property --- welllll, it's a balancing act. Right to shelter for two days versus the public's right to not have evidence in a potential criminal case destroyed. Since I'm doubting that there's a right to housing (e. g. although it might not be pleasant, alternative arrangements could have been made at a shelter), I think the initial kick-out is okay. As for the time period kicked out, see the paragraph above. I'm not saying that there's nothing there, but there may not be enough facts to really tip it one way or the other.

The doors were locked at about 2 o clock Saturday morning and they arrived on Monday with a search warrent. The town is in Southern New Hampshire, not too far from Mancester. As for due diligence I'm not 100% sure what that is. It applies to crimes without mens rae, beyond that I'm not sure what it is, could you explain it and how it could apply to this case?

I mean due diligence in terms of them getting the warrant. Nada to do with the crime itself, it's the police I'm talking about. Since the kick-out was Sunday at 2 AM (when the bars close, perhaps?) and then the warrant was brought on Monday, that's not two days. It may very well be due diligence, I don't know what the Magistrates' schedules are in NH. There are places where there is someone to sign a warrant pretty much 24/7, but in the backwoods that's probably not going to be the case. Since this is near Manchester it's probably not God's country so there may very well be a 24/7 JP (or whoever signs the warrants). That's research you'll need to do.

I think you're both forgetting something important here: this is a dorm room on a university campus. The university, therefore, is the landlord, and it is quite likely that the residential housing contract that the students entered into when they agreed to live in the dorm room has some provision in there allowing the university to do what it did here.