Recent content by Chris J

I've noticed when measuring static pressure in a duct most people use L shaped tubes with small holes in the sides, very similar to a pitot tube except it's missing the hole in the end for dynamic pressure. What is the reason for using an L tube with holes in the sides for static pressure...

I don't have a diagram handy, but here's a few pictures that show the design of the blower assembly. These are not of the actual one I'm dealing with, but it's the same style. The motor is mounted inside of one end of the wheel but with a decent gap around it so it can pull air through. The...

Between the weather, and me coming down with what I think was the flu (it wasn't fun, regardless) I finally got things cleaned up and back together but barely got to test anything. The only thing peculiar that caught my attention was the blower wheel wasn't centered in the housing, remember it...

No, the motor fits into one side of the squirrel cage and is located in the unit. I didn't see any places I thought air could get in other than the less than perfect filter housing. Are you saying there's a chance balancing issues could make the squirrel cage it self sing at specific speeds...

I started working on everything and then got sidetracked, so I still need to finish cleaning and put everything back together. It's still cool out, so I haven't been in a huge rush. After thinking about it, I suspect the blower wheel is as dirty as it is just because of the high humidity it's...

Ok so, as much as I didn't expect this there actually was some dust buildup on the vanes. I assume from the high humidity (blower being after the evaporator) and apparently dust gets through even a merv 8 filter with foam gaskets all around it. Can't be much, because the evaporator was very...

After looking at things a bit there are some possible weak points I forgot about. I feel most of it is sealed in ways that shouldn't fail for a long time. But there's two "canvas connectors" I made up, one for each side of the air handler which decouple it from the duct work. Since they're...

Mostly metal with short 3-5 foot runs of flex duct pulled straight and tight at the ends of each run. The ductwork right at the air handler is rectangular and made from 20 gauge galvanized steel. Everything else is insulated 26 or 28 gauge galvanized round duct. All joints were siliconed on...

So basically, I've created a musical instrument and I need to break it. Last time I checked the blower was spotless, so I doubt anything has changed with that. Does the frequency tell me anything about what I'm looking for, size wise? I.E. 130-150Hz should be something around 4 to 4.5 foot...

Stupid question... If it is oscillating around 130-150Hz, does that mean the wavelength is roughly 7.5-8.5 feet? And if so does that mean whatever is producing the sound should be around 4 feet long?

Hi all, I'm having an issue with an ECM blower in my central air conditioner making a ringing /oscillating noise 130-150Hz. It's talking to me, I just don't understand what it's saying but I have a feeling someone might. I installed this system and all associated ductwork 7 years ago. It uses...

To answer all questions No it's not built yet just something I was thinking about after seeing something else similar and it made me think it could be used as a swing. After thinking about it I'll probably just give up on the idea as there's too many unknowns and I'm not sure it's worth it. I...

Yep It's just not sold as the usual stores that just carry typical pipe.

138" between posts.

The reason for the single post design is limited space. It's basically a copy of this, except 4' higher and 1 size larger pipe and substantially larger footings, I think the commercially available design only calls for 32" deep. I'm considering on shortening it as maybe 4' higher is just too...