NOAA Reports - Base for Degree Days

[caerhays]

Hi all,

I am running Cumulus 3072 here in the UK. In the NOAA Reports the base for degree days Heating and Cooling is set at 18.3 degsC. Most UK sites seem to recommend 15.5 degsC for UK residential detached houses.
My questions are:

1. Why is it set to 18.3 degsC
2. If I change it in the settings will it simply change the HDD and CDD for each month as I re-generate the reports, without affecting anything else.

Advice would be appreciated.

Regards, Phil

[PaulMy]

Hi Phil,

1. Why is it set to 18.3 degsC

I am not familiar with the science of degree or cooling days and this may be somewhat helpful https://www.weather.gov/key/climate_heat_cool

2. If I change it in the settings will it simply change the HDD and CDD for each month as I re-generate the reports, without affecting anything else.

Regarding Cumulus, in the Cumulus1 Help Steve had included some information on using the threshhold. Click on Configuration - NOAA Setup. I am assuming CMX will be similar, but Mark would be able to confirm.

I have also attached a screen capture in case you can't open the attached help file.


EDIT: Cumulus WiKi https://cumuluswiki.org/a/Heat/cold_deg ... _threshold

Enjoy,
Paul

[caerhays]

Thanks Paul.
I've just realised 18.3 degsC is 65 degsF so it is based on the assumed value for a residential property in the USA.

I currently have no evidence to support a need to change this so I will leave well alone. I do understand degree days as I used to use them in my work. I could with some effort calculate a value for my property because I have a full year of weather data plus my corresponding monthly electricity and gas usage. A job for a cold winter's day in lockdown I think.

Many thanks, Phil