Conference article

Modeling and Coordinated Control of an Air-Source Heat Pump and Hydronic Radiant Heating System

Christopher R. Laughman
Mitsubishi Electric Research Laboratories, Cambridge, MA, USA

Scott A. Bortoff
Mitsubishi Electric Research Laboratories, Cambridge, MA, USA

Hongtao Qiao
Mitsubishi Electric Research Laboratories, Cambridge, MA, USA

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Published in: Proceedings of the 2nd Japanese Modelica Conference, Tokyo, Japan, May 17-18, 2018

Linköping Electronic Conference Proceedings 148:11, p. 77-85

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Published: 2019-02-21

ISBN: 978-91-7685-266-8

ISSN: 1650-3686 (print), 1650-3740 (online)


Hydronic radiant heating systems embedded in building constructions are receiving increased interest due to their potential for high energy efficiency and improved thermal comfort, but their slow time constants pose challenges when controlling space conditions. We address this problem via a system architecture that combines the radiant heating system with a separate air-source heat pump serving the same space. In this paper, we develop a new coordinating control method for this proposed system by using a set of reduced order models generated from a set of coupled Modelica models of the individual subsystems. This new control architecture does not require significant modification of standard heat pump control architectures, and results in both improved thermal comfort and reduced energy consumption.


radiant heat transfer, heat pump, thermally active building systems, control, Modelica


Dassault Systemes AB. Dymola. 2018 FD01.

ASHRAE. HVAC Systems and Equipment Handbook.

ASHRAE, Atlanta, GA, 2008.

ASHRAE. Thermal environmental conditions for human occupancy.

ASHRAE 55:2017, Atlanta, GA, USA, 2017.

A. Beghi, L. Cecchinato, and M. Rampazzo. Thermal and comfort control for radiant heating/cooling systems. In IEEE Conference on Control Applications, 2011.

N.T. Gayeski, P.R. Armstrong, and L.K. Norford. Predictive pre-cooling of thermo-active building systems with low-lift chillers. HVAC&R Research, 18(5):858–873, 2011.

M. Gwerder, B. Lehmann, J. Tödtli, V. Dorer, and F. Renggli. Control of thermally-activated building systems (TABS). Applied Energy, 85:565–581, 2008.

M. Gwerder, J. Tödtli, B. Lehmann, V. Dorer, W. Güntensperger, and F. Renggli. Control of thermally activated building systems (TABS) in intermittent operation with pulse width modulation. Applied Energy, 86:1606–1616, 2009.

M. Koschenz and V. Dorer. Interaction of an air system with concrete core conditioning. Energy and Buildings, 30:139–145, 1999.

C.R. Laughman and H. Qiao. On the influence of state selection on mass conservation in dynamic vapor compression cycle models. Mathematical and Computer Modelling of Dynamical Systems, 23:262–283, 2017.

C.R. Laughman, H. Qiao, V. Aute, and R. Radermacher. A comparison of transient heat pump cycle models using alternative flow descriptions. Science and Technology for the Built Environment, 21(5):666–680, 2015.

C.R. Laughman, H. Qiao, S.A. Bortoff, and D.J. Burns. Simulation and optimization of integrated air-conditioning and ventilation systems. In Proc. of the 15th IBPSA Conference, pages 660–669, 2017.

A.A. Márquez, J.M.C. López, F.F. Hernández, F.D. Muñoz, and A.C. Andrés. A comparison of heating terminal units: Fan-coil vs. radiant floor, and the combination of both. Energy and Buildings, 138:621–629, 2017.

Modelica Association. Modelica specification, Version 3.4, 2017. URL

Modelon AB. Vapor Cycle Library User Guide, 2018. v2.0. K-N. Rhee, B.W. Olesen, and K.W. Kim. Ten questions about radiant heating and cooling systems. Building and Environment, 112:367–381, 2017.

C.C. Richter. Proposal of New Object-Oriented Equation- Based Model Libraries for Thermodynamic Systems. PhD thesis, Technical University of Braunschweig, 2008.

H. Tang, P. Raftery, S. Schiavon, J. Woolley, and F.S. Bauman. Performance analysis of pulsed flow control method for radiant slab system. Building and Environment, 127:107–119, 2018.

M.Wetter. Multizone building model for thermal building simulation in Modelica. In International Modelica Conference, pages 517–526, 2006.

M.Wetter,W. Zuo, and T.S. Nouidui. Modeling of heat transfer in rooms in the Modelica "Buildings" library. In Proceedings of Building Simulation 2011, pages 1096–1103, 2011.

M. Wetter, W. Zuo, T. Nouidui, and X. Pang. Modelica Buildings library. Journal of Building Performance Simulation, 7 (4):253–270, 2014.

M. Wetter, M. Bonvini, and T.S. Nouidui. Equation-based languages – a new paradigm for building energy modeling, simulation, and optimization. Energy and Buildings, 117: 290–300, 2016.

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