# Tag Info

### Why don't AC units run condensate over the outdoor condenser coils?

Designing a product for installation at site means that the designer has no idea or control over where the condenser coils are going to be. Will they be located over a door step? Over a car park? ...

### Does it matter where a reduction happens in a fluid system to the amount of back pressure at the source?

Would there be less back draft and better performance if all the ducting was 7" until it goes out to the wall? Yes Would it help even if it was 7" through the cabinet before (or after) the ...
• 7,074

### Why don't AC units run condensate over the outdoor condenser coils?

There are indeed proposals to combine the air conditioner's heat pump action with that of evaporative cooling to increase the overall efficiency of the air conditioner. One way is to run the cold ...
• 15.1k
1 vote

### How do I calculate the amount of watts that a heating element needs inside a box?

After some Calculations i ended up using the amount of air (m³/s), air density kg/m³, temperature differance and a mollier diagram to get to my ansver, witch ended up to be around 700W thanks for all ...
1 vote

### Pressure drop in air flowing through an array of tubes

Try using this calculator to calculate the flow rate for one tube at a given pressure drop and then multiplying the flow rate with the number of tubes, the calculator has an explanation akin to a ...
1 vote

### Why don't AC units run condensate over the outdoor condenser coils?

Window units blow the condensate over the condenser. I suspect that issue is that you haven't seen the nastiness that condensate lines turn into. You don't want that all over your condenser pad and ...
• 7,074
1 vote

### Does it matter where a reduction happens in a fluid system to the amount of back pressure at the source?

The fan belongs somewhere in, or downstream of, the smallest section. Commercial range hoods have the fans on the roof. Then you have no backdrafting. If your fan is bigger than 7" and located in ...
• 4,850
1 vote

### Heat needed to prevent freezing of valve expanding compressed air

To determine the maximum possible heat needed you can try the following first determine density of fluid at the starting conditions. determine volume flow rate (Vdot) by dividing by density. Use ...
1 vote
Accepted

### What are the downsides of reversing fan and filter direction on a Corsi-Rosenthal box so the fan blows air into the box?

In this link is what you are describing. One could add some legs and add a 5th filter opposite the fan so the static pressur is reduced and less risk of dust escaping the fan blade boundary. I hope ...

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