Thanks for the comment. Temperature variations depends on the location. Different jurisdictions have more stringent design temperatures projected for the future. For example, in NYC we have to size the HVAC equipment based on "The Climate Resiliency Design Guidelines". That document pretty much increases the requirement for outdoor design temperature. For instance: ASHRAE Design Condition at 1% T = 86.6°F and Climate resiliency indicates T = 98°F (for 2050) Below is the link for the document in pdf : www.nyc.gov/assets/sustainability/downloads/pdf/publications/CRDG-4-1-May-2022.pdf In order to see projections there are different methods such as: Global Climate Models (GCMs), Regional Climate Models (RCMs), and Representative Concentration Pathways (RCPs). I hope this helps.
Hello Mr.HVAC Easy Math, I found your video very informative. You explain everything most funniest way. Mean coincident dry bulb(MCDB), Mean coincident wet Bulb why ASHRAE mention like this not simply Dry Bulb, Wet Bulb temperature .Waiting for your prompt response.
Thanks for you kind comment! Basically mean represents average depending on winter or summer and coincident indicates same time as. According to ASRHAE fundamentals the MCDB data allows to consider various operational peak conditions. I might make a video explaining each component of the weather data and one would be the MCDB. Stay tune
Thank you for this video, I found it very useful. Where did you find the values for indoor conditions (70,75,50%)? Are these general values or are they location specific?
These values are based on ASHRAE 55 indoor conditions for comfort zone. In the link you can find great info too: www.hvacproblog.com/ma_ri_code_interior_design_conditions
Daily Range is shown as MDBR "Mean Daily Temperature Range" under the annual column. I showed it quickly in the video (13:05). Once you go to the website and scroll down you will be able to find it by month.
EN: Hello, thank you for this very simply explained video. I have a question: in winter, when you say that there's a 99% chance that the temperature will be above this figure, you're referring to (as an example) : DB = -19.1°C (99%) so if I understand correctly there is a 99% chance that my temperature will be above -19.1°c. So it will be colder than that (the figure is negative). For example, if my dry bulb temperature is DB = 11°C in winter. So there's a 99% chance that my figure is above 11°C? in which case it will be warmer than 11°C! I don't understand. Because the use of "above" has confused me. As I understand it, I would have said 99% of the time it will be colder than the temperature displayed. I have the impression that the signs (negative and positive) distort the "above" a little. FR: Bonjour, merci pour cette vidéo très simplement expliqué. J'aurais une question, en hiver, lorsque vous dites qu'il y a 99% de chances que la température soit au dessus de ce chiffre, vous faites référence à (comme exemple) : DB = -19.1°C (99%) donc si je comprends bien il y a 99% de probabilité que ma température soit supérieure à -19.1°c. Donc il fera plus froid que ça (le chiffre est négatif). autre exemple, si j'ai une température sèche de DB = 11°C en hiver. Donc il y a 99% de chance que mon chiffre soit au dessus de 11°C? dans ce cas cas là il fera plus chaud que 11°C! je ne comprends pas. Car le fait d'employer "au dessus" m'a mélangé. Pour moi, selon ma compréhension, j'aurais dis 99% du temps il fera plus froid que la température affichée. J'ai l'impression que les signes (négatifs et positifs) faussent un peu le "au-dessus".
Thanks for your kind comment. I might make a video to add another example. But in this case, the temperature is in Fahrenheit (°F) which is 19.2°F (Positive). %design temperature is based on all the hours in the year which is 8760 hrs where the temperature is most likely to be above this number. In this case, from 8760 hrs about 8672hrs the temperature will be above 19.2°F Now in Celsius degrees we have a negative which is -7.1°C. So In Winter 8672hrs the temperature will most likely be above -7.1C (based on 30 year of data). When saying above I mean warmer than -7.1°C (-6.1, -5.1, -4.1, -3.1, -2.1, -1.1, 0.1, 1.1, 2.1..........)
Hello, I have another question please. In the 'Extreme Annual Design Conditions' section, for example: For a 5-year return period, the extreme minimum dry-bulb temperature could reach -26.4°C. Does this mean that every 5 years, it is possible for the temperature to drop to -26.4°C for a period of 1/5, but I am confused about what this '1' represents. Does it mean 1 hour or 1 day every 5 years that the temperature could reach -26.4°C?
Sorry for the late reply. Generally, we size the equipment based on 1%/ 99% design temperatures and we coordinate equipment with the manufacturer's representative. I believe they select in more detail and they consider the parameters you are mentioning. I would advise when selecting either a DOAS system or Mixed air RTU to check with the equipment's sale representative.
Sorry for the late reply. In general, for sizing equipment we perform heat load calculations for which we use outdoor design conditions based on 99%/ 1% or more conservative 99.6%/0.4% (designer's choice). For adiabatic condensers I would use the same considerations regardless. For more in depth detail, coordination with representative is encouraged since they have their own selection tools.
Sorry for the late replies, my notification where off by some reason. You can find the daily temperature range almost at the bottom of the ASHRAE screen shot I shared in the video. Go to the website and by scrolling down (rows 33 to 37) you will find it.
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thanks sharing for this video
Thanks for your kind words!
Thanks for the video. I want to know how do we consider temperature variation, say for next 50-60 years?
Thanks for the comment. Temperature variations depends on the location. Different jurisdictions have more stringent design temperatures projected for the future. For example, in NYC we have to size the HVAC equipment based on "The Climate Resiliency Design Guidelines". That document pretty much increases the requirement for outdoor design temperature. For instance: ASHRAE Design Condition at 1% T = 86.6°F and Climate resiliency indicates T = 98°F (for 2050)
Below is the link for the document in pdf :
www.nyc.gov/assets/sustainability/downloads/pdf/publications/CRDG-4-1-May-2022.pdf
In order to see projections there are different methods such as: Global Climate Models (GCMs), Regional Climate Models (RCMs), and Representative Concentration Pathways (RCPs).
I hope this helps.
@@hvaceasymath Thanks a lot!
Hello Mr.HVAC Easy Math, I found your video very informative. You explain everything most funniest way. Mean coincident dry bulb(MCDB), Mean coincident wet Bulb why ASHRAE mention like this not simply Dry Bulb, Wet Bulb temperature .Waiting for your prompt response.
Thanks for you kind comment!
Basically mean represents average depending on winter or summer and coincident indicates same time as. According to ASRHAE fundamentals the MCDB data allows to consider various operational peak conditions. I might make a video explaining each component of the weather data and one would be the MCDB. Stay tune
Thank you for this video, I found it very useful. Where did you find the values for indoor conditions (70,75,50%)? Are these general values or are they location specific?
These values are based on ASHRAE 55 indoor conditions for comfort zone. In the link you can find great info too: www.hvacproblog.com/ma_ri_code_interior_design_conditions
funny and informative video thanks
Thanks for your kind comment!
Hello,
Will you please explain from where we can find daily range ?
Daily Range is shown as MDBR "Mean Daily Temperature Range" under the annual column. I showed it quickly in the video (13:05). Once you go to the website and scroll down you will be able to find it by month.
EN:
Hello, thank you for this very simply explained video.
I have a question: in winter, when you say that there's a 99% chance that the temperature will be above this figure, you're referring to (as an example) :
DB = -19.1°C (99%) so if I understand correctly there is a 99% chance that my temperature will be above -19.1°c. So it will be colder than that (the figure is negative).
For example, if my dry bulb temperature is DB = 11°C in winter. So there's a 99% chance that my figure is above 11°C? in which case it will be warmer than 11°C! I don't understand. Because the use of "above" has confused me.
As I understand it, I would have said 99% of the time it will be colder than the temperature displayed.
I have the impression that the signs (negative and positive) distort the "above" a little.
FR:
Bonjour, merci pour cette vidéo très simplement expliqué.
J'aurais une question, en hiver, lorsque vous dites qu'il y a 99% de chances que la température soit au dessus de ce chiffre, vous faites référence à (comme exemple) :
DB = -19.1°C (99%) donc si je comprends bien il y a 99% de probabilité que ma température soit supérieure à -19.1°c. Donc il fera plus froid que ça (le chiffre est négatif).
autre exemple, si j'ai une température sèche de DB = 11°C en hiver. Donc il y a 99% de chance que mon chiffre soit au dessus de 11°C? dans ce cas cas là il fera plus chaud que 11°C! je ne comprends pas. Car le fait d'employer "au dessus" m'a mélangé.
Pour moi, selon ma compréhension, j'aurais dis 99% du temps il fera plus froid que la température affichée.
J'ai l'impression que les signes (négatifs et positifs) faussent un peu le "au-dessus".
Thanks for your kind comment. I might make a video to add another example. But in this case, the temperature is in Fahrenheit (°F) which is 19.2°F (Positive). %design temperature is based on all the hours in the year which is 8760 hrs where the temperature is most likely to be above this number. In this case, from 8760 hrs about 8672hrs the temperature will be above 19.2°F
Now in Celsius degrees we have a negative which is -7.1°C. So In Winter 8672hrs the temperature will most likely be above -7.1C (based on 30 year of data). When saying above I mean warmer than -7.1°C (-6.1, -5.1, -4.1, -3.1, -2.1, -1.1, 0.1, 1.1, 2.1..........)
Hello, I have another question please. In the 'Extreme Annual Design Conditions' section, for example: For a 5-year return period, the extreme minimum dry-bulb temperature could reach -26.4°C. Does this mean that every 5 years, it is possible for the temperature to drop to -26.4°C for a period of 1/5, but I am confused about what this '1' represents. Does it mean 1 hour or 1 day every 5 years that the temperature could reach -26.4°C?
I will get back to you on that one.
I usually use .4% Evap conditions for 100% OA unit, but which design conditions is more suitable for RTU that has RA. Maybe Dehum?
Thanks for your comment! I will get back to you on that.
Sorry for the late reply. Generally, we size the equipment based on 1%/ 99% design temperatures and we coordinate equipment with the manufacturer's representative. I believe they select in more detail and they consider the parameters you are mentioning. I would advise when selecting either a DOAS system or Mixed air RTU to check with the equipment's sale representative.
Sir plzz tell how can select another value wb if i choose heating only db value are here
Thanks for your comment! Could you elaborate more…? Thanks
Which values would I use for sizing adiabatic condensers?
That’s a great question. Let me get back to you on that one.
Sorry for the late reply. In general, for sizing equipment we perform heat load calculations for which we use outdoor design conditions based on 99%/ 1% or more conservative 99.6%/0.4% (designer's choice). For adiabatic condensers I would use the same considerations regardless. For more in depth detail, coordination with representative is encouraged since they have their own selection tools.
How to select daily temperature range in that website?
Sorry for the late replies, my notification where off by some reason.
You can find the daily temperature range almost at the bottom of the ASHRAE screen shot I shared in the video. Go to the website and by scrolling down (rows 33 to 37) you will find it.
from where to purchase this software ? plz guide me . send a link
No problem, and thanks for the comment. It not a software but it is online free of charge.
ASHRAE Climate link is below:
ashrae-meteo.info/v2.0/index.php?lat=38.94&lng=-77.45&place=%27%27&wmo=724030&ashrae_version=2009