[TRNSYS-users] Type 1231 with type 700 and type 941

[miriam di matteo]

Dear all, I'm modeling on Trnsys an radiators heating system of a 3 story
building from the 1980s. I'm using the Type 1231 as radiators and type 700
as Boiler. Types 1231 are connected by Type 56 as internal gain(0.8
convective; 0.2 radiative).
I have two questions / problems:

1) The internal rooms temperatures are below 20°C (comfort temperature)
when the system is on.  I don't understend why.
The parameters and input are:
Type 700
-Rated Capacity  248400 kJ/hr (69kW)
-Minimum Turn-Down Ratio 0.51; If I understod right it is the ratio between
minimum and maximum Boiler capacity. (35kW/69kW)
- Intel fluid tempertature: i connected this input with radietors outlet
temperature trought a mixing valve (type 649);
- Intel fluid flowrate: like intel fuid temperature.
- input control signal: the system work from 14.00pm to 22.00pm
- set point temperature : 80 °C

Type 1231
I inserted 13 different Type 1231, one per appartament.
- Design surface temperature is 65°C
- Design Air temperature is 20 °C
- I calcolate the flowrate as (radiator capacity)/(Cpw*deltaT)
deltaT=Tin-Tout=20°C, for each type 1231

2) I want to replace the boiler with a heat pump (A-W HP Type 941) but
leaving the existing radiators.
do i have change the type 1231 parameters?
For example Tsd from 65°C to 50/45°C?

Thanks a lot to everyone,
Best regards
Miriam
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