Formula to turn on the heating in summer

[cvrb2]

Hello,
I have created some absolute heating profiles that I'm using just during the winter (31 Sept-31 March).
The thing is now I would like to turn on the heating during the summer as well, but only when the inside temperature is under 19°c.
I tried to put in my profiles some formula indicated in the Help, but it seems not working.
I tried:
** int(100*ta/19) (it's approximately the same formula that I used to open the windows)
** if(ta<19,19,ta)
When I ran an analysis with Apache with these 2 formula, I obtained an error message.

I also tried:
** ta<21
Nothing happens with this one. But I think this one has to be use with "Modulating" profiles, and in our case all our profiles (daily, weekly, annual) are "Absolute" profiles.

If someone knows how to help me...
Thanks in advance.

Regards.

[cvrb2]

Just to illustrate my problem, if you go on this link http://www.hostingpics.net/viewer.php?i ... apture.png, you'll find the inside temperature over the year for the living room of the house I'm designing.
I have many detailed profiles, but basically:
- the heating is on from 15 sept to 15 April
- windows open from 15 april to 15 sept, when the inside temperature is above 26°c
- mechanical ventilation (0,5 ACH) is on continuously.

I obtain several aberrations as you can see on the link. That's why a formula to turn on the heating when the inside temperature is under 19°c could be useful...

[maiquesk]

Hi,

I think that you use Macroflo. Maybe you can close your windows when inside temperature is below 19°C.
If you use Macroflo with the option "Opening threshold temperature" to 26°C, your windows are open when inside temperature is above 26°C, but they do not close when inside temperature is below 26°C, they stay open.

And for your heating problem, you can creat a week absolute profil with 19°C continuously, and you take it between 15 April to 15 sept in your annual absolute heating profil. Normally there is no need a complicated formulas.

Regards