Does anyone have evidence that DanCap is all wrong?

[aaron_k]

Hello,

I've seen many anecdotal comments from many posters that the Danfoss DanCap program gives radically short cap tube lengths. Does anyone have direct experience with this? Anyone? Help!

[desA]

Why don't you test it for yourself, instead of slagging off a perfectly sound company?

Build a small prototype & test if your theory is correct, or not.

Then tell us the results of your experiment.

[Chef]

Hello,

I've seen many anecdotal comments from many posters that the Danfoss DanCap program gives radically short cap tube lengths. Does anyone have direct experience with this? Anyone? Help!

It's a sensible question and deserves a sensible answer. Dancap does seem to give results quite different from other sources such as Supco and ACC and you may wish to use the predictions with caution. If you compare results from the above sources and also ASHRAE you will see a great range of possible solutions.

You may like to try
http://www2.the-acc-group.com/java/X?cgi=cubigel.infotecnica.InformacionTecnicaArticulo2.pattern&seccion=informaciontecnica

Here they have cap tube recommendations for various gases and differant evaporator temperatures.

The main problem with sizing the tube length (especially with LBP systems) is the large range that the tube must operate over, if the tube is sized for final conditions it is likely to be too long and cause excessive startup pressures and possible overloads. If the tube is sized for acceptible startup loads it will be shorter and less efficient at final conditions.

Chef