What do you need help with?

Selecting Design Conditions

Follow

CoolCalc uses design conditions specified in ACCA tables. It's important to note that heating and cooling design temperatures are not the most extreme temperatures that may occur in your area but rather the typical high/low temperatures that HVAC systems should be designed for in your area. ACCA design temperatures are updated approximately every 5 years.

Cool Calc will automatically select the closest weather station to the home based on distance. However, it will present the user with the nearest five stations in case there is one that more accurately reflects the temperatures for that area. You may override the ACCA specified design temperatures only if local building code allows.

Heating Design Temperature – In the winter, the temperature should remain above this value 99% of the time. This value is automatically populated based on the weather station selection, but can be overwritten.

Cooling Design Temperature – In the summer, the temperature should remain below this value 99% of the time. This value is automatically populated based on the weather station selection, but can be overwritten.

The indoor design temperatures are set to 75 degrees in the summer and 70 degrees in the winter.

Have more questions? Submit a request

Comments

  • Avatar
    Don Snow

    Why can't we adjust the indoor temperatures like in the beta version?

  • Avatar
    Cool Calc Support

    The indoor design conditions fields exist in our calculation engine, but have not yet been added to the user interface. This is on our roadmap and will be implemented during one of our future code releases.

    Best Regards
    Cool Calc Team

  • Avatar
    patrick ward

    It would be helpful to be able to adjust the indoor temperature. I have customers that want to maintain 72 degrees when its 115 outside

  • Avatar
    Lee Hulse-Smith

    I'm in Toronto and the HVAC inspector won't issue my permit until he sees the Winter Indoor Temperature set to 72 degrees. I was hoping not to do all this by hand, but it's looking like I may not have a choice. Do you have any suggestions?

  • Avatar
    Cool Calc Support

    Hi Lee,

    We have adjusted the indoor temperature to 72 degrees for your project. As of right now we need to do this directly in the database. We will look into adding the capability for users to do this themselves in a future release. ACCA Manual J procedures prevents users from changing the indoor temps which is why we didn't add this capability to the user interface originally, but we understand that some local code enforcers mandate certain temperatures be used. If you run into this again just contact us and we can override the temperatures on our end.

    Best Regards

    Bill

  • Avatar
    Lee Hulse-Smith

    You're the best Bill. Thanks!

  • Avatar
    Stephen Thompson

    in April of 2018 you stated that customizing indoor temperatures "will be implemented during one of our future code releases." That was more than a year ago. This is an extremely important feature that should be easy to release. Should I open a support ticket every time I want to customize the indoor temp for my projects?

  • Avatar
    Peter Burry

    Exactly as Stephen above said. Add the feature back, otherwise this program is a whole lot less useful...
    I dont understand why youre saying you cant allow users to change temps because of code. A substantial amount of users and potential users are professionals. And even if they werent or a simple home owner wants to do a calculation, just put a warning before allowing anyone to change design temperature.
    This is really frustrating...

  • Avatar
    glen lee

    How can i enter actual r values for rafters instead of using default values

  • Avatar
    Cool Calc Support

    Hi Glen,

    You can adjust the r-values under Construction Details -> Construction Feature Groups. Simply, click the section you want to edit and change the drop-down fields. Sometimes you have to adjust some other values for certain r-values to appear. For example, r-values for cavity insulation in a 2x4 wall is limited to R-15, but if you change the wall to 2x6 you can select higher r-values. If the r-value you are looking for is higher than what is available for selection, create a support ticket with us and we can take a look. Thank you

  • Avatar
    Ed LaFontaine

    Hello, I want to revise my SIP wall R-value to 23 (U=0.43). I see no option for doing this. Using 6.5" wall @ 0.05 U (R=20) seems to be the only option I find.

  • Avatar
    Cool Calc Support

    Hi Ed,

    If you choose a frame construction of 2x6, you can then select R-21 as a cavity insulation. From there, you can add additional board insulation of R-2 to achieve your desired R-23 assembly r-value.

Powered by Zendesk