Thanks for this review. It's on ebay in the UK (for £45) with slightly different gauge design, but still has the problem of excessive range and thus poor accuracy. There are a couple of other for £10 more which only have 3 ports but more sensible gauge ranges. So I think I'd conclude the same as you 'OK, but probably worth spending a little more for gauges you can actually read to better than nearest 5psi.
There are a lot of daft laws but the one about venting refrigerants to the atmosphere is pretty sensible. So check carefully for system pressure, and if you have got gas to get rid of then you really do need to spend another $250 on a vacuum/recovery pump and a tank to fill (or take to someone who has one). Just the 0.6Kg of R134a in an average car if vented is 0.9 tonnes of CO2 equivalent, or the same as a London/New York flight or driving 4000km/3000miles. If it's an older machine with Freon (R12) in then that's 7 times worse, so 6 tonnes, which is the world average_annual_ emissions, just in the minute or so it takes to let it out. (i.e. ~20,000 miles driving, or 1.5 UK to Australia return flights). It really is something to avoid. The depressing thing is just how much this stuff leaks out anyway (at least for automotive systems) - it's expected to have to recharge every few years which implies something like 10% extra emissions over the fuel burning. So A/C tightness is just as important as fuel consumption (from an emissions POV).
Recharge every few years? I have 30-40 year old tractors and pickups on the same freon from the factory. Unless you have a compressor shell out. There is no reason to open the system.
Thanks for this review. It's on ebay in the UK (for £45) with slightly different gauge design, but still has the problem of excessive range and thus poor accuracy. There are a couple of other for £10 more which only have 3 ports but more sensible gauge ranges. So I think I'd conclude the same as you 'OK, but probably worth spending a little more for gauges you can actually read to better than nearest 5psi.
There are a lot of daft laws but the one about venting refrigerants to the atmosphere is pretty sensible. So check carefully for system pressure, and if you have got gas to get rid of then you really do need to spend another $250 on a vacuum/recovery pump and a tank to fill (or take to someone who has one). Just the 0.6Kg of R134a in an average car if vented is 0.9 tonnes of CO2 equivalent, or the same as a London/New York flight or driving 4000km/3000miles. If it's an older machine with Freon (R12) in then that's 7 times worse, so 6 tonnes, which is the world average_annual_ emissions, just in the minute or so it takes to let it out. (i.e. ~20,000 miles driving, or 1.5 UK to Australia return flights). It really is something to avoid.
The depressing thing is just how much this stuff leaks out anyway (at least for automotive systems) - it's expected to have to recharge every few years which implies something like 10% extra emissions over the fuel burning. So A/C tightness is just as important as fuel consumption (from an emissions POV).
Recharge every few years? I have 30-40 year old tractors and pickups on the same freon from the factory. Unless you have a compressor shell out. There is no reason to open the system.