IES-VE User Forum

Hi guys,

Query about the radiant fraction setting when modelling underfloor heating.

Default settign for all systems is 20% (0.2), am I right in saying that this means that of the heat output from the system, 20% of it is radiant and the other 80% is assumed to be conductive and/or convective?

I may be wrong but I would have thought that Undefloor heating would be mostly conductive and radiative. I was thinking perhaps a figure of 0.5?

Is there any IES documentation that explains the operation of this function clearly?

cheers,

C

Hi,

this is from the ApacheView user guide (can be accessed via the Help >> User Guides http://www.iesve.com/downloads/help/ve2 ... heView.pdf)

Heating plant radiant fraction
The fraction of the heating plant’s output that is in the form of radiant, rather than convected, heat. A value of 0.0 is appropriate for warm air heating and a value of 0.9 for high-temperature radiant heaters. See Table 13 for further guidance.

Phil

Top man Phil, thanks for that.

Sorry, where can I get access to "Table 13"?

these really to need to be made as hyperlinks, you can access it in the document Apache Tables (also accessible via Help >> User Guides >> Thermal section).

I think IES get a hard time for "lack of documentation" but we have been working to correct this lately, I'm finding lots of the answers to things people ask us is actually in the user guides already and they are available as an excellent resource to all. Maybe it's the "marketing" and naming that needs revised a touch.

http://www.iesve.com/downloads/help/ve2 ... Tables.pdf

Phil

Fantastic Phil, just what I needed. I was almost certain I could recall my Uni lecturer telling me to put in 0.5 for underfloor heating, obviously I should trust my memeory a bit more

Thanks for that,

Colin

Never doubt your instincts!