This study looked at using a ground source heat pump to heat buildings in Kazakhstan's cold climate. They made a heating system using a heat pump that moves heat from the ground to water for heating. By testing it in real conditions, they found it worked well, almost exactly as predicted, and was even better when they used a refrigerant called R152a. That refrigerant is good but flammable, so they also looked at others like R450A, R513A, R1234yf, and R1234ze. These could also work, though a bit less efficiently. They found the parts that make up the system can waste energy, with the compressor being the biggest problem. Overall, these findings show different refrigerants could be used instead of the one usually used, making heating systems greener.