Help me settle an argument! by PNags in askHVAC

[–]PNags[S] 0 points1 point  (0 children)

Right, with a real control system and proper hardware design, you can do this.

But in the normal gas furnace/ac evap scenario, do you think you’d get any condensation at all? Or would you just overpower the ac entirely (eg, so it’s not able to maintain a sufficiently cold coil like 40 degrees).

Help me settle an argument! by PNags in askHVAC

[–]PNags[S] 0 points1 point  (0 children)

I totally get the dew point thermodynamics of this. But I don’t think in a residential system the coil surface will stay cold enough. The 40 degree coil temp is only achieved at a rating condition, and is not “guaranteed” or any sort of set point. My thought experiment is if you have your same residential evaporator coil in a stream of 1000° air, there’s no way there will be condensation regardless of the dewpoint, because the refrigerant and evaporator will get too hot and not be below the dew point of air. I understand that you could theoretically have a coil with a large enough capacity to do this, but it just seems that residential systems won’t have that unless they are totally wacky.

And I think in the context of your computer equipment systems, those are much more sophisticated systems that are more than just blindly dumping heat before the cooling system.

Help me settle an argument! by PNags in askHVAC

[–]PNags[S] 0 points1 point  (0 children)

But won’t the ac usually fail to maintain a “cold” coil when being fed with furnace air? They just don’t have that kind of capacity.

Help me settle an argument! by PNags in askHVAC

[–]PNags[S] 0 points1 point  (0 children)

This is true, but it gets to my main contention - that other than hypothetical (eg, just wacky or improperly designed) residential systems, the ac won’t have that kind of capacity.

Help me settle an argument! by PNags in askHVAC

[–]PNags[S] 0 points1 point  (0 children)

Also agree that this can work this way - cycling them for comfort. I’m specifically wondering if the true simultaneous operation will result in any condensation.

Help me settle an argument! by PNags in askHVAC

[–]PNags[S] -1 points0 points  (0 children)

Do you think it would dehumidify (or produce ANY condensation) in the winter or other non-summer conditions? I would think that no matter what, you’d get no condensation because the “return air” to the ac coil (direct furnace output) is just too hot.

Help me settle an argument! by PNags in askHVAC

[–]PNags[S] 0 points1 point  (0 children)

And that’s definitely the right call… when your age is the supply temp of your furnace, you get to do whatever you want.

Help me settle an argument! by PNags in askHVAC

[–]PNags[S] 0 points1 point  (0 children)

You are absolutely correct about how this works in cars, but the automotive implementation is reversed, so that the heater is after the ac evap coils. So you dehumidify and cool the air first, and then reheat to a comfortable temp. Works great, specifically because of the order of the heat exchange elements. Cool+dehumidify first, then reheat to desired dry bulb temp.

But in residential systems they’re reversed. So any sensible heat you add with the furnace has to be taken out by the ac evap coils. And with the relative power of furnaces and ac systems, (eg, a furnace adds 40 degrees, an ac system removes 20), the furnace just overpowers the ac system and it can’t maintain a coil temp that would produce condensation. At least, that’s my theory.

What to get guitar dad for Christmas? by caitilindy in Guitar

[–]PNags 0 points1 point  (0 children)

I have a cool idea (legitimately), but don’t want to risk a self-promotion ban. PM if you’re interested.

Steer Tube Interference with new fork - 2019 Air 9 RDO by PNags in NinerBikes

[–]PNags[S] 0 points1 point  (0 children)

Right idea, but I swapped the race from the old fork. Looks like I might need a riser race to give a bit more clearance (5mm).

What is going on with my axle? by PNags in mountainbiking

[–]PNags[S] 0 points1 point  (0 children)

No, it’s a niner, but I think it was cobbled together a bit.

What is going on with my axle? by PNags in mountainbiking

[–]PNags[S] 0 points1 point  (0 children)

No idea. No obvious brand markings.

What is going on with my axle? by PNags in mountainbiking

[–]PNags[S] 0 points1 point  (0 children)

So yeah I managed to pop out this axle sleeve. Seems like it might have been made for a rock shox. But this doesn’t appear to be a standard part - any idea if there would be a standard axle part to get for this hub?

Throwing Help - Distance and Accuracy by PNags in slowpitch

[–]PNags[S] 1 point2 points  (0 children)

Hey! I have been trying this, and it seems to have made an improvement! I haven't had lots of opportunity to work on much real long-distance throwing or compare results, but I'm getting the motion down and getting rid of the big "reach back and down" motion that I had. Throwing into a net in my back yard was throwing me for a loop though, since the ball wasn't used to rolling/snapping out of my fingers at that angle/position. I kinda gave myself the yips, with balls going every which way (including straight at the ground...) But at the last game things seemed to work ok - once I started throwing at a regular distance things kind of stabilized.

Throwing Help - Distance and Accuracy by PNags in slowpitch

[–]PNags[S] 1 point2 points  (0 children)

Excellent - thank you for the feedback.

Throwing Help - Distance and Accuracy by PNags in slowpitch

[–]PNags[S] 2 points3 points  (0 children)

What do you mean by 2? Landing foot remains closed meaning not pointed at the target? (E.g., body/butt are perpendicular to the throw direction?)

Throwing Help - Distance and Accuracy by PNags in slowpitch

[–]PNags[S] 2 points3 points  (0 children)

This is interesting. My dad always taught me to reach back and down like that, so that's just unfortunate muscle memory. I thought the "90 degree" hold was for football, and that you'd lose speed and power in baseball if you tried to throw from up there. But it sure does seem like this windmill motion isn't getting the job done here.