Re: [TRNSYS-users] air to air heat pump(type-966)

Hi Alastair,

Thanks a lot! for answering question( how to calculate total electricity consumption by a house)

I am using air to air heat pump (unit11-type 966). In type-966, there are some coefficients such as TC1 to TC6, SC1 to SC6, CP1 to CP6, BF1 to BF6 and HT1 to HT6. These coefficients values are zero by default.

TC1 to TC2 used to calculate the Total capacity multiplier = TC1 + TC2*EWB + TC3*EWB^2 + TC4*OADB + TC5*OADB^2 + TC6*EWB*OADB

SC1 to SC6 used to calculate Sensible capacity multiplier = SC1 + SC2*EWB + SC3*EWB^2 + SC4*OADB + SC5*OADB^2 + SC6*EWB*OADB

CP1 to CP6 used to calculate Energy input ratio multiplier = CP1 + CP2*EWB + CP3*EWB^2 + CP4*OADB + CP5*OADB^2 + CP6*EWB*OADB

BF1 to BF6 used to calculate Bypass fraction multiplier = BF1 + BF2*EWB + BF3*EWB^2 + BF4*EDB + BF5*EDB^2 + BF6*EWB*EDB

HT1 to HT6 used to calculate Heating EIR multiplier = HP1 + HP2*OADB + HP3*OADB^2 + HP4*EDB + HP5*EDB^2 + HP6*EDB*OADB

Just for trial, I set all these variables equal to 1. Then, it gives following error

“”Error-- Unit -38 type- 3 Total Fatal Errors : 1

Error – Unit 11 type-966 TRNSYS Message 118 : The subroutine SAT of the utility routine PSYCHROMETRICS, which calculates the thermodynamic properties of moist air, has been called with a temperature below absolute zero (-273 C). Please check the TYPE routine which calls the psychrometrics routine for possible sources of errors. Reported information : Error 118 “”

(I am not using type-3 in model.)

When all of these constants equal to zero, the electricity consumption by heat pump(type-966) is zero. I have tried to look but neither documents nor help forum contains any information regarding type966.

also, I have checked the user manuals for 5ton heat pumps but user manuals don’t include information about these coefficients.

Any explanation where I can get them or suggested values for these coefficient?

I will greatly appreciate any help!

Thanks,

Sandeep Chahal

Research Assistant

UAB

From: TRNSYS-users <trnsys-users-bounces@lists.onebuilding.org> on behalf of Alastair McDowell <alastair.mcdowell@energyae.com>
Sent: Sunday, October 4, 2015 8:11 PM
To: TRNSYS users mailing list at OneBuilding.org
Subject: Re: [TRNSYS-users] How to calculate electricity consumption by a house?

Hi Sandeep,

There is no type to specifically calculate electricity consumption of a house. You will have to do some calculations in the Studio to sum up all the electrical energy usage throughout the year.

For example, if your lighting scheme is controlled by a timing schedule or control function, you can sum up (using a Type 24 integrator) the total period of time that the output control signal was on, and multiply by the electrical energy consumption of the unit. Remember the base units of energy rate (kJ/hr) multiplied by hours on (hr) will output the energy in kJ, easily converted to kWh.

If using a schedule within TRNBuild, you can output the value of the schedule by creating a new airnode output, NType 28 gives the value of all schedules. Double click to specify which schedule to output.

Depending on what type of heat pump you are using, look through the outputs to determine the electrical energy usage of the heat pump. For example Type 941 air-water heat pump, output 15 gives the total heat pump power (compressor + controls + blower) which also includes auxiliary heating. Integrate this power over the year to find the total electrical energy consumption of the heat pump.

I hope this answers your question.

Kind regards,

Alastair McDowell

Engineering Consultant

Energy Analysis & Engineering – Enabling innovation for a sustainable future

T: +61 450 600 842

E: alastair.mcdowell@energyae.com

608 Harris St Sydney NSW 2007 Australia | http://www.energyae.com

From: TRNSYS-users [mailto:trnsys-users-bounces@lists.onebuilding.org] On Behalf Of Sandeep Singh Chahal
Sent: Sunday, October 4, 2015 1:16 PM
To: trnsys-users@lists.onebuilding.org
Subject: [TRNSYS-users] How to calculate electricity consumption by a house?

Hello TRNSYS users,

I am working on a TRNSYS model to calculate the total electricity consumption by a two story building which includes all household appliances.

Firstly, I want to calculate the total electricity consumption by this house.(using type 56). This house includes household appliances (defined with in TRNbuild) and connected with a heat pump.

I have looked into the documents but I didn’t see any type to calculate the total electricity consumption (KWh) by a house. I might have missed it.

Is it possible to calculate the total electricity consumption? If yes, which type I should use?

Thanks in advance!

Sandeep Chahal

Research Assistant

UAB School of Engineering