Add toggle for use of activity-generated air speed

[t-kramer]

Currently, based on ASHRAE 55 and EN 16798, we use activity-generated air speeds for metabolic rates above a certain met limit to account for elevated air speeds from movement. However, in certain places, e.g. gyms, people with high metabolic activity may not generate elevated air speeds, causing the model to misrepresent their case. We plan to add a toggle to the models to allow turning off the default use of activity-generated air speeds.

[t-kramer]

@stefanoschiavon I implemented this for the ASHRAE-55 and EN-16798 pages. As discussed, I added a button to the group at the bottom, ensuring it’s present but not overly prominent to avoid confusion. In terms of UI, it's not beautiful but consistent with the other buttons and pop-ups. By default, it's turned on and follows the standard.

Should I also add this to the other tabs, including upload, before submitting a PR and merging it into the live version? Just let me know and I'll wrap this up.

@FedericoTartarini tagging you for info. We got this feature request at the recent CBE meeting and thought it is worth implementing. Feel free to share your thoughts.

[huffleflumph]

This has recently caused confusion at our design firm and presents a major issue with LEED compliance on our sports projects. You're correct in pointing out that not all high-MET activities generate air speed. I believe the assumption that the ASHRAE researchers made was that all high-MET is cardio (and running in a single direction). Activities such as weightlifting, studio HIT, Spin Class, and similar are high MET and nearly no linear movement.
I have a similar concern with the use of DYNAMIC CLOTHING and suggest that there be a similar toggle for that.

[stefanoschiavon]

@t-kramer I am happy with the implementation. I suggest the following change: "When metabolic rate is above 1 met, the tool automatically include the air speed generated by physical activity (for example, air speed generated by walking)......(for example, exercising on stationary equipment). Please add it to other tabs.

@huffleflumph please keep in mind that at this stage ASHRAE does not allow for this even if it makes sense, an addenda to the standard should be developed. Regarding dynamic predictive clothing, it was developed for predicting how much you dress based on outdoor temperature. In a design of a sport facility, you should input the expected clo value.
If you a refering to the automatic adjustment of the clothing value (not the dynamic predictive clothing), then I may not agree that a toggle is needed because the effect is there even if you do not have wind.

[huffleflumph]

Noted. I get that we're at the mercy of the way ASHRAE writes their standard. If they don't let us "turn off" relative air speed, then I suppose we are stuck. But let's just take a step back and ask if this makes sense:

Let's say I'm playing tennis in my shorts and Tee shirt... something that many of us have done. I can't imagine that my optimal comfort zone would be 75 to 84F. That's bananas, right?

Now compare this to the EN-16798 standard:

This seems to make way more sense. You would want a cool space when you're working that hard. 60F would be ideal - as many of us know from experience.

Am I missing something? Did I use the tool incorrectly?
I would love to see what happens to the ASHRAE 55 standard chart when the Relative Air Speed is turned off.

[stefanoschiavon]

@huffleflumph, I tend to agree. Most of the thermal comfort models were developed for met rates < 2 met, so I guess that they do not predict very well at high rate, moreover, the ASHRAE 55 model has issues with how it manages high air speed: https://www.linkedin.com/pulse/accuracy-ashrae-iso-pmv-models-stefano-schiavon-4eboc/

[FedericoTartarini]

Thank you very much for implementing this, I however would like to say that I think we should be separating two self generated airspeed components.

1. the person moving into the air (for example walking) this adjustment should be considered separately and it should not be accounted from this equation.
2. limbs and body parts moving. This generates a relative higher speed and this is what I believe this adjustment is for. Consequently in principle even if a person is doing a static exercise or running on a treadmill, they will still be experiencing a high relative airspeed even in a gym. However, I don't know how much research has been done on this topic and I don't know how much this general equation is accurate.
   I think the best solution here would not to change much these adjustments, but actually to limit the PMV model to low metabolic rates as Stefano suggested. I don't think it's a good idea that the ASHRAE 55 is applicable to met up to 4 met.

[stefanoschiavon]

@FedericoTartarini
I agree with the idea to limit ASHRAE 55 to 2 met but this is out of our control.
I partially disagree with your second point. I could be doing leg presses or lift weights with a high met without generating much air movement. In some cases I may (for example, running on a treadmill). I doubt that there is much research on this, so for know, just being able to toggle on and off the option of self-correction may be valuable. It will be up to the users to figure out if the correction works in the specific case.

[FedericoTartarini]

Yes, I agree. Sorry, with point 2 I meant that for some specific activities the correction should be applied, but it should not be applied in other scenarios, like for instance like press.

[stefanoschiavon]

@FedericoTartarini are you ok implementing this change in the tool as proposed by @t-kramer?

[t-kramer]

@FedericoTartarini Thanks for input, you are making some valid points, as always @stefanoschiavon It's ready to push but I'll be holding off for now until both of you make a decision how to implement it.

[FedericoTartarini]

At the moment, unfortunately, I don't have time because I have a lot of things that I need to finish before I travel. I may be able to work on this in June.

[t-kramer]

@FedericoTartarini I think @stefanoschiavon meant if you are okay with me implementing the change?