[TRNSYS-users] documentation about Type917 and Type653

[Matt Duffy]

Dear Alessia,1. Type917 does indeed consider the air temperature - whether that be an indoor or outdoor temperature in the respective data files.\Tess Models\SampleCatalogData\Air-to-WaterHeatPump\Type917_CorrectionFactors_Heating.Dat\Tess Models\SampleCatalogData\Air-to-WaterHeatPump\Type917_CorrectionFactors_Cooling.DatThere are indeed external air temperatures, so when you obtain your performance data from the manufacturer it can indeed have a larger range. Type941, the other AWHP, has a larger air temperature range.2. Type653 is intended to use with Type56/TRNBuild and used iteratively: it passes a temperature to the small layer in TRNBuild/Type56 which solves for the heat transfer to be passed to Type653. Therefore, I don't think that it can be used with another building component. I will ask my colleague about the source code. He sometimes uses different iteration schemes, so it may be correct or a typo.3. Type1231 issue. Please be more specific with your simulation cr!
 ash with the small timestep, or simply try something like 0.125 hr and it should work. Also, please make sure that you're using the heat pump component correctly, the controller is turning it on and off correctly, and make sure it has flow.Best regards,Matt Duffy----- Original Message ----- From: "" Sent: Fri, April 8, 2011 3:48 Subject:Re: [TRNSYS-users] documentation about Type917 and Type653 Dear Matt, thanks for your availability. Here my questions: 1) TYPE 917 I cannot understand why in the performance data files there isn’t the dependence on the external air temperature. I have understood that there is another file with the correction factors to correct the performance on the basis of the indoor air temperature. But why the indoor temperature? Is the heat pump thought to be installed and supplied with the indoor air (the air temperature in the correction factors file at heating mode are high indeed, so it is obvious they cannot refer to outdoor conditi!
 ons)? Anyway, even if in such a way the air temperature variation is c
onsidered, which is the reference air temperature for the performance data file? Supplier catalogue data depend on the external air temperature. 2) TYPE 653 If this type is not connected to TYPE 56, which is the best way to use it? I would like to connect it to TYPE 690, connecting the top surface heat transfer (Type653) to the sensible load (Type690). Does it make sense? Checking the source code, I have noticed the code lines reported below. Is it possible that in the third line you meant T_Prev_B instead of T_Prev_E? Probably it is a typo..... !Calculate the top surface temperature in energy balance mode T_Prev_T=Tave_Slab/2.+T_Conv_T/4.+T_Rad_T/4. T_Prev_E=Tave_Slab/2.+T_Conv_E/4.+T_Rad_E/4. T_Prev_E=Tave_Slab/2.+T_Conv_B/4.+T_Rad_B/4. Iters_Surface=0 What is the difference between Type 653 and Type 993? 3) TYPE 1231 I have had a lot of troubles with this component. I have coupled it with a heat pump. I got that when the heat pump is off and there isn’t any flow rat!
 e, the inlet and outlet temperature from the radiator make non-sense fluctuations. Moreover, after the heat pump is switched off, all the temperature are set to the last outlet temperature from the radiator and they don’t drop off to the initial ambient values (this seems consistent with the source code, but not realistic!). Moreover, trying to use small time steps the simulation crash. I cannot understand why. Thanks in advance for your help. Regards. Alessia 
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