Set Watts Parameter Problem

Hi all,

I’m using dynamo 1.0 and am finding some strange behaviour when trying to set a watts parameter in Revit. Using dynamo I’m doing some simple math (area * watts/m² to obtain total watts for the space), I can see the correct results appearing in a watch node but the numbers appearing in Revit are about 11 times less than expected. So for example when the result should be 100 (watts) it appears in Revit as 9 Watts (9.29 to be exact). I remember having to do a similar conversion in my past when converting ft² to m² and for some strange reason I think this conversion is barging it’s way in during the set parameter process.

So there’s a few things to note here:

  1. Area conversions should not even enter in to this discussion. I’m simply trying to write a value to a wattage parameter. I know that I’m using an area parameter earlier in the equation but for testing purposes I’ve just tried setting a parameter to a value of 100 and the strange values persist.

  2. I appreciate that there is a unit conversion node in Dynamo. I thought well I’ll just use this to reverse this bizzare occurrence and just move on but this seems to fall over once I start using larger numbers.

The question I’m asking is how can I get around this?
Further questions are has anyone experienced this in the past? Have you successfully dealt with this? Am I completely losing my mind and doing something silly?

Thanks in advance.

So I have some progress on my initial query above which may close this out for any who find themselves in a similar situation in the future.

As Vikram eluded to in a previous post, “area” and inherently the units they are in does come in to the equation when considering wattage. So a conversion in dynamo to account for sq ft rather than sq m is needed to produce the correct wattage results which is doable using the “Convert between units” node.

The problems that I thought I was having with this node producing erroneous results was due to the fact that I was validating the wattage values being pushed back in to Revit using a calculated value in a schedule (visually comparing the two). After some digging I realised that my Dynamo results were in fact much more accurate as the calculated values used rounded values from the schedule itself to produce total wattage whereas Dynamo extracted actual area values to many decimal places of precision.

All part of the process of learning to use a new tool, cheers!

Hi Greg,

Dynamo units are in feets. In your case it is using watts/ft^2. You need to convert it watts/m^2 (w/ft² x (1 ft/0.3048 m)² = w/m² )


Precisely Kulkul.

Thanks again.