# The Efficiency of the Heat Pump in the Heating System Using Heat from Exhaust Gases after the Condensing Boiler

The thermodynamic efficiency of heat pump hot water supply schemes using heat from exhaust gases after the condensing boiler was determined. It was established, that there is the optimum degree of cooling of the flue gases in the evaporator heat pump, which corresponds to the maximum specific useful effect received from the exhaust gases heat utilization by HP based on the cost to the heat pump compressor drive.

# Effectiveness Analysis of Recirculation Dryer with a Heat Pump

The results of the thermodynamic analysis of conventional and heat pump conveyer convective drying of grain are shown in this article. The purpose of this work is to analyze the impact of recirculation on the energy efficiency of traditional and heat pump grain dryers. The mathematical model should also shows energy advantage of heat pump dryers in relation to traditional. Modeling of processes is performed for the first period of drying at a constant rate of moisture removal from the grain. The calculations were made for wheat grain.

# Thermodynamic Efficiency of the Heat Pump Air Conditioning System

The purpose of this paper is to analyze and compare thermodynamic efficiency of heat pump air conditioning systems. The paper deals with simplest schemes of the heat pump air conditioning system. Analytically we obtain dependences to calculate these schemes. We also show graphs of the main parameters characterizing the effectiveness of these schemes depending on the ambient temperature. We analyze the effectiveness of the heat pump air conditioning systems.

# The Optimal Characteristics of Ground Heat Exchangers for Heat Pump Heating Systems

This paper investigates characteristics of ground heat exchangers for heat pump heating systems. We obtain the optimal ratio between characteristics of ground heat exchanger (tube length of one loop, pipe diameter, and brine velocity in the circuit for heat pump systems) under given conditions of its application (the intensity of selecting heat from soil, thermo-physical characteristics of the heat carrier, temperature conditions of the heat pump system).

# Optimum Operation of the Heat Pump in the Low-Temperature Heating Systems Using the Ground Heat

The paper under scrutiny studies optimum operation of the heat pump in low-temperature heating systems utilizing the ground heat. When using the ground heat in the heat pump heating system there is an optimal degree of cooling brine in the evaporator of the heat pump corresponding to the minimum total cost of electricity for heat pump heating system as a whole. Through experiments conducted, we determine that the optimal degree of cooling brine in the evaporator of the heat pump largely depends on the constants A complex.

# Thermodynamic Efficiency of Heat Pump Systems of Air Heating

This article discusses the two most common heating systems based on air heat pumps: air heating scheme of ventilation and the so-called split-system Since the literature lacks data on sound analysis of the peculiarities of different air heating systems, their thermodynamic efficiency under different operating conditions, the article is devoted to addressing these issues. It provides an analysis of heat pump systems, air heating, the resulting values of energy utilization for such systems, given the comparative analysis of the two most common heat pump systems using heat air.

# The Energetic Efficiency of Heat Pump Ventilation System with Heat Recuperator and Exhausted Air Recirculation Application

This paper demonstrates the results of operation analysis of the heat pump ventilation system with a heat recuperator and exhaust air recirculation. We also obtain the coefficient value of energy application for these systems. Finally, we make some conclusion on simultaneous application of the heat pump and the exhausted air recirculation used in the ventilation systems.

# The determination of the local on the heat transfer length at condensation vapor R407C in a horizontal pipe

This paper reports on the influence of mass transfer on local heat transfer on the length of a smooth horizontal pipe at inside condensation mixture R407C. Moreover, we make the calculation of mass transfer component R134А at condensation vapor R407С, taking into account certain assumptions. We illustrate that the presence of the diffusion boundary layer near the surface of condensate film causes the decrease in the intensity of heat transfer at condensation refrigerant R407C on the initial site, comparing with the similar conditions for R22.

# Еnergy efficiency of the combined heat pump system of low-temperature water heating and ventilation

The paper deals with the basic scheme of the combined heat pump system of low-temperature water heating – “floor panel heating system” and ventilation. We present the results of еnergy efficiency analysis of this system both taking into account and disregarding the energy expenses for air transportation through the heat pump evaporator.