[Bldg-sim] Solar Thermal for In Floor Radiant Heating

[Luke Morton]

Correct me if I'm wrong here, but I read the question as less about radiant
floor heating, and more about solar thermal water heating with a backup
boiler.

If my memory serves from this very listserv, eQuest does not model thermal
storage (hot water, or otherwise) very well; it considers only the 1st law
of thermodynamics, that is- BTU's in-- BTU's out.  It does not monitor
temperature of the thermal storage.  So, if you put 1 MBTU into a water tank
(no matter the size or starting temperature), you'll get 1 MBTU of useful
heating out.  This also means that it cannot model the need for a backup
when temperatures in the thermal storage are not sufficient for the load.
At least, that's the information that I gathered when I tried to answer your
exact question Maudud.

For a more careful analysis, I've heard others mention the use of SunREL,
EnergyPlus, and TRANSYS.   For the time being, I have been creating some
rather unwieldy spreadsheets to answer these sorts of questions for myself.


--Luke Morton
Energy Engineer
Palo Alto, CA


On Tue, Aug 31, 2010 at 9:12 AM, Chris Jones <cj at enersave.ca> wrote:

>  The only issue with FPH is that outdoor air and exhaust fans may not be
> simulated.
>
>
>
> System type FPH meets your needs.
>
>   <http://inputtemplateforastandardfphunit.htm>
> Floor Panel Heating System
>
> The Floor Panel Heating System provides heating for one or more zones by
> circulation of heated fluid through a network of pipes embedded in the
> floor or ceiling. A single pump, rather than the primary-secondary pumping
> arrangement shown in the schematic, is installed for single-zone systems.
> Space temperature in each zone is controlled by varying the temperature of
> the fluid circulating in that zone. Hourly head addition rate is determined
> for this system exactly as for other types of systems. Pumping energy
> associated with this system is accounted for by the PUMP attached to the
> CIRCULATION-LOOP. The ratio of panel heat losses to panel heating output
> must be estimated by you and entered; see the keyword PANEL-HEAT-LOSS in
> the ZONE command). The program assumes that this ratio of heat loss to
> heat output remains constant over the full range of panel output.
>
> [image: []]
>
>
> Figure 59  Floor panel heating system
>
> Other names and/or applications for FPH
>
> None. Note that the simulation does not account for the radiant comfort
> aspects of panel heating; therefore, a lower heating setpoint is
> appropriate.
>
>
> Chris Jones
> 14 Oneida Avenue
> Toronto, ON M5J 2E3.
> Tel.  416-203-7465
> Fax. 416-946-1005
>
>
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-- 
Lucas Morton
619-721-3180

"Perhaps we'll see you later, and then some..."
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