Metal 45deg Tee ???

[newood2]

Is there any technical data to show that Tee A has less airflow resistance than Tee B, or it’s just assumed because of the difference in design? I can’t find any documentation online to say that it does other than from the company that sell it, like for example, Wilkes Machinery says in it’s online add. "Made of galvanized steel, these tee fittings branch off at 45 degree angles. This design allows for change of direction and size reduction with a minimal amount of airflow resistance."
The thing is I can get Tee B locally for $12, whereas Wilke and PSI sell Tee A for $19 and $29 plus shipping.
Is there a big difference that would worth the extra cost?


Tee A


Tee B



Howie

[Tequila]

I haven't looked for any studies or anything, but to me it looks like Tee A is going to have a lot more turbulent airflow than Tee B. That turbulence would mean that you end up with MORE airflow resisitance in Tee A.

So without really looking into it, my engineering gut feeling says that Tee B is a better option, even if they were the same price.

[Tom Miller]

Note that "Tee A" (wye, actually) has what looks like a 3" line joining into a 4" run. Since that's a less standard part, it might be the reason for the higher cost.

Otherwise, I agree with Tequila, that the portion with the higher cross-sectional area would more likely be disruptive to airflow (certainly to air velocity) than not.

In any case, I can't imagine it could be noticeably better OR noticeably worse.

Regards,
Tom

[Tom Slick]

are you sure you don't have the two mixed up, "tee A" looks like HVAC parts and should be cheaper then "tee b". keep in mind that sheet metal for dust collection is much thicker then for air conditioning/venting. D/C sheet metal will be 20-24 guage, hvac stuff with be 24-26 guage. that may be part of the price difference that you are seeing.


some good info can be found here: www.airhand.com

[newood2]

are you sure you don't have the two mixed up, "tee A" looks like HVAC parts and should be cheaper then "tee b". keep in mind that sheet metal for dust collection is much thicker then for air conditioning/venting. D/C sheet metal will be 20-24 guage, hvac stuff with be 24-26 guage. that may be part of the price difference that you are seeing.

Tom, the Tee B pic shown is actually 20 gauge($73 at Airhand), but the 26 gauge is $12.99 at the local metal store, not that thin stuff at HD. For 5" and 4" diameter ductwork I think it's pretty stiff.I'm new to this so I'm going by common sense to figure the 26 gauge pipes are strong enough not to collapse under suction pressure IMHO. But your point is noted.

[Tom Slick]

for a home shop 26 gauge is probably ok. generally the runs aren't long enough to create much resistance and collapse.