[TRNSYS-users] ROOM TEMPERATURE FOR CONTROL DECISION

[Edward Halawa <Edward.Halawa@unisa.edu.au>]

Dear All,

I'm simulating a solar air heater to heat a house during winter. I have two
zones: LIVING and BEDROOM. I make a schedule as follows: from 07.00 - 23.00 the
collector heats the LIVING zone, and from 23.00 - 7.00 the BEDROOM. The house
is modelled using PREBID, but the schedule is carried out in TYPE 56.

I need either LIVING or BEDROOM temperature (TAIR) at any time as input to
control unit. Since I need only one TAIR at any time, I connect the HOUSE (TYPE
56) with a mixer (TYPE 11) to get TAIR from either LIVING or BEDROOM zone
according to the above schedule. However, in Reference manual it is suggested
not to use the outlet temperature from the mixer for control decision because
it cannot handle properly the no-flow situation.

My questions:
1. How should I get TAIR from either LIVING or BEDROOM zone as input to my
control unit without using TYPE 11 ?
2. When there is no load, there will be no air flow (from the collector) to the
room. In this situation, is TAIR coming as outputs from TYPE 56 really the true
air temperature of each room ? I noticed that room temperatures are always much
higher than the outside temperature even during the winter period. For example,
room temperature in my simulation can reach as high as 35C even though outside
temperature is as low as 15 and the irradiance is relatively low.

Thanks in advance for your kind help.

Edward Halawa