Occupancy Sensors Light Your Way Up Dark Stairs
LESLIE: Jim in Virginia finds The Money Pit on WJFK. And you’ve got an electrical question. How can we help?
JIM: Yes. Actually, I have two questions and I know you’re … they’re slightly a little different from what your … I told your producer. But hopefully, you can help me.
The first question is I visited a model home recently and they had actuators on the first step and the top step that turned on the lights in the stairway.
JIM: Do you … is that a … do you know where I could pick up something like that or is that an application that you would recommend?
TOM: Those are called OC sensors. It stands for occupancy sensors.
TOM: You often see them in – they’re like motion detectors and you often see them at staircases. You’ll also see them in bathrooms or places like that so that when you walk in …
LESLIE: Or closets.
TOM: Yeah, or closets. So you walk in, it’ll pick up the movement. They come in different degrees in terms … like the electric eye has a defined field and some of them are narrow and some of them are really wide and some of them are adjustable so you can control where somebody has to actually walk to trip on the light.
LESLIE: And how long it’ll stay on.
TOM: Yeah, and how long it stays on and all of that.
JIM: (overlapping voices) Right. Now this … this was actually a pressure sensor that … you don’t know anything like that?
TOM: You mean on the steps itself so that when you stepped on it, it did that?
JIM: Yes, sir. Yes, sir.
TOM: Huh. Well, that’s interesting. I don’t think I’ve ever seen one of those but it sounds like … somewhat like the same technology they would use for an alarm system.
TOM: You know, I think that might be a little more difficult to find than an occupancy sensor which is fairly common. You’ve probably seen them around; you just didn’t realize them. They just look like …
LESLIE: They’re even really common in security systems. They sort of trigger, if you have a system on your wall that will let you know such and such has movement in what area. We have one in our stairway that lets you know if somebody’s walked by. So it’s sort of the same type of concept. It almost even looks the same. It’s a little rounded unit with a light on it.
JIM: Right. Yeah, I’ve seen something like that. And if you don’t mind, I have another question.
TOM: Sure, go ahead.
JIM: Okay. Regarding HVAC systems. I have a local code that says I have to have a fireblock going up the wall …
JIM: … into the ceiling.
JIM: But I want to … but I want to run an HVAC duct from the ceiling down the wall.
JIM: How do I get past the requirement to have a fireblock?
TOM: I don’t think you have to have a fireblock if there’s a duct that’s … a continuous duct that goes through the stud bay from top to bottom.
JIM: Okay. And if … and if I want to actually go …
TOM: (overlapping voices) It would only be for an open stud bay.
JIM: And if I want to go through a 2×4, is there an application that I can … how do you get through the 2×4?
TOM: Now, is the 2×4 that you want to cut through one of the vertical studs?
JIM: It’s one of the horizontal studs that go across …
TOM: You just break it out of the way.
JIM: Break it out.
TOM: Yeah, one of the … one of the fireblocks? You just take it out of the way.
TOM: It’s not load bearing. That’s just a fire stop. The fire stops are important in open bays.
TOM: But if it’s not … if you’re going to run a duct inside of it, then it’s no longer open.
TOM: Alright, Jim?
JIM: (audio gap) lot. I appreciate it. Thank you very much.
TOM: (overlapping voices) There you go. You’re very welcome. Two questions for the price of one.
JIM: There you go.
TOM: (overlapping voices) 888-666-3974 is the telephone number. 1-888-MONEY-PIT.