Hi
The story...
I am tinkering about with an old Fuji Electric r22 split system, making it into a water heater for my small inflatable pool, about 6000L. At the trial stages at the moment, I have made a heat exchanger and have timed ho long it takes to heat about 110L of water. The water went from 14*C to 36*C in 32min with a flow rate of 90L/min. I cant quite remember what the unit capacity was as a split, I think it was about 6kw. It has worked out to be about 5.3kw without calculating heat losses (haven't insulated anything at this stage). What I need to find out is if the unit has too much refrigerant in it. The pipe-run is about 1.5m and the exchanger has about 7m of 3/8" pipe in it. With water at 36*C the pressure on gas side is 310psi which seems way high to me. I remember when I took the unit out of my mates place he said that someone had charged it up about a year beforehand and at that stage I thought it was high.
The questions...
If I take the gas out and charge in the correct amount (1600g) is this still going to be too much? How do you do a superheat calculation if the indoor coil is immersed in water? I have also been told that maybe I should put some sort of pressure reduction in so the compressor wont fail. It already has capillaries as the txv but was he talking about on the suction side near the compressor and would this just create a pressure build-up somewhere else that is equally serious?
The story...
I am tinkering about with an old Fuji Electric r22 split system, making it into a water heater for my small inflatable pool, about 6000L. At the trial stages at the moment, I have made a heat exchanger and have timed ho long it takes to heat about 110L of water. The water went from 14*C to 36*C in 32min with a flow rate of 90L/min. I cant quite remember what the unit capacity was as a split, I think it was about 6kw. It has worked out to be about 5.3kw without calculating heat losses (haven't insulated anything at this stage). What I need to find out is if the unit has too much refrigerant in it. The pipe-run is about 1.5m and the exchanger has about 7m of 3/8" pipe in it. With water at 36*C the pressure on gas side is 310psi which seems way high to me. I remember when I took the unit out of my mates place he said that someone had charged it up about a year beforehand and at that stage I thought it was high.
The questions...
If I take the gas out and charge in the correct amount (1600g) is this still going to be too much? How do you do a superheat calculation if the indoor coil is immersed in water? I have also been told that maybe I should put some sort of pressure reduction in so the compressor wont fail. It already has capillaries as the txv but was he talking about on the suction side near the compressor and would this just create a pressure build-up somewhere else that is equally serious?