When I start my car that has cooled down to 20°F overnight, how can running the A/C greatly speed defrosting of the windshield? Is the evaporator in the A/C going to get anywhere near cold enough to condense moisture out of 20°F air? And if it did, how to manage the ice that would form on the...
Agreed. But part of the air passing through the defroster is from the passenger compartment. If the evaporator temperature isn't lower than the dew point temperature in the passenger compartment, then the air conditioner is doing no dehumidification when it is freezing outside.
The inside...
Does a car's air conditioner do any dehumidifying in winter?
I entered these words in a search engine: winter car air conditioning
Several websites say something similar to: Anything that helps to take moisture out of the equation – ie. air-con – will clear fogged glass.
I would not expect...
I don't have much to say about the "power equation" scenario other than to observe:
One one hand, "Power loss over obstruction = volumeflow*dP = 10*1000 = 10 kW" -- losing power from the airstream should cool it.
On the other hand, "dT = power loss / (massflow * cp)" -- that is, the "lost"...
Agreed.
But:
The obstruction is not removing energy from the control volume because it is not a turbine or other device capable of transmitting shaft work across the boundary of the control volume.
Heat transfer is not removing energy from the control volume, per the OP: "The obstruction is...
It is not clear for which "expert advice" you gave thanks.
Did anyone provide a reassuring answer to your subject query?
This expectation is disquieting: "when smoke starts billowing out from the seals, insulation, and paint burning."
This suggests that all relevant failure scenarios have not...
Thank you, JG2828, for the voice of sanity:
I don't see any major security issues with using field installed network switches.
Far too many people seem to perceive of IT types as exalted wizards who speak ex cathedra when they invoke the S-word. Security is to be valued above motherhood, and...
Some might nitpick at the terminology, but the wanted functionality is available here -- inexpensively:
https://www.amazon.com/NETGEAR-5-Port-Ethernet-Unmanaged-FS105NA/dp/B00002EQCW
NETGEAR 5-Port Fast Ethernet 10/100 Unmanaged Switch (FS105NA)
Price: $21.99
I don't (necessarily) want a...
I don't want to move terabytes of data. I want one point of connection between an ATC head end and one VLAN that makes connections only to a few controllers from the same manufacture -- with Ethernet hubs that allow those controllers to talk to end devices.
IRstuff made my point: limit what can...
A system (operating system or network) that is as vulnerable as we hear about on the news has a fundamental flaw in its design. A system that accepts many signals sacrifices security by design.
For as much money as the IT industry has thrown at it and given the number of allegedly smart people...
I have a project where the IT department disallows field-installed Ethernet hubs for communication between devices on the automatic temperature control (ATC) system.
Instead, they insist on a dedicated cable from a switch in a room that is under the control of the IT department to each Ethernet...
One thought was to use floating ball-check type of backwater valves between the air gaps and the storm water risers,
comparable to this:
https://www.zurn.com/media-library/web_documents/pdfs/specsheets/58903-pdf
But good locations for the backwater valves have not been found.
We talked about...
Compositepro, there is a trap before the sump and an air gap in the sump of the pump, comparable to:
This image is not the actual installation I am asking about, which collects condensate from a number of FCUs. This image was found on the internet for the purpose of illustrating the...
What engineering rationale would prohibit disposing of pumped air-conditioning (A/C) condensate to a storm water riser without an air gap?
The National Standard Plumbing Code (NSPC) requires routing A/C condensate through an air gap before it connects to a pipe in a plumbing system.
I think...
