Digital Gauges

[jw-lu597]

Not trying to start a war here, but why get digital gauges? I know everyone has their preferences, but digital gauges seem like total overkill to me. I could buy a bag full of other quality tools for the price. Maybe I'm missing something -- do they do something that a regular gauge doesn't do or are they just easier?

[engineerdave]

What's that Digi-Cool AK900 going for? $300? Smart money.

[AStudent]

What's that Digi-Cool AK900 going for? $300? Smart money.

Yup...$300 plus shipping if you order from Canada...so 340 plus the cost of hoses, which you are going to buy with any digital set anyway.

My ak900 with 5ft. hoses with a ball valve on each hose cost me roughly $430....compare that to what the supply house wants to charge for the Testo 550...$387 with no hoses.

[AStudent]

Not trying to start a war here, but why get digital gauges? I know everyone has their preferences, but digital gauges seem like total overkill to me. I could buy a bag full of other quality tools for the price. Maybe I'm missing something -- do they do something that a regular gauge doesn't do or are they just easier?

Digital gauges do make life a ton easier....not to mention they last longer than analog from what I've heard.

[jw-lu597]

But how do they actually get accurate A/C superheat readings from the gauge port?? Here in some of the Chicago high rises, the temp leaving the evap can be quite different than the temp at the service port of the condensing unit, especially with a crappy install and broke down suction insulation. Again, not arguing, just curious with the preference. I never heard of anybody wanting digital gauges until I joined this forum.

[AStudent]

But how do they actually get accurate A/C superheat readings from the gauge port?? Here in some of the Chicago high rises, the temp leaving the evap can be quite different than the temp at the service port of the condensing unit, especially with a crappy install and broke down suction insulation. Again, not arguing, just curious with the preference. I never heard of anybody wanting digital gauges until I joined this forum.

Getting superheat and subcool readings with a digital set is the same as getting readings using analog, you still have to hook temp sensors to the line...the difference is all of your readings are on one screen, in digital numbers, and you are not carrying several tools around for the same job.

Digital gauges can be and claim to be more accurate than analogs, showing real time changes that are going on in your system, and showing the readings that would be between each hash mark on your analogs.

[engineerdave]

But how do they actually get accurate A/C superheat readings from the gauge port?? Here in some of the Chicago high rises, the temp leaving the evap can be quite different than the temp at the service port of the condensing unit, especially with a crappy install and broke down suction insulation. Again, not arguing, just curious with the preference. I never heard of anybody wanting digital gauges until I joined this forum.

Some guys might tell you "Set your superheat for 12 degrees at the bulb" or some such number like that. This, to me, can be very misleading information. You want to know what the compressor manufacturer recommends for Superheat at the Compressor. As long as your compressor is operating within mfr's specs, the rest will be easy. Or easier, anyway. Set your Superheat to keep the compressor happy.

[jw-lu597]

I see what you're saying. That is true, and usually if you set the correct superheat out of the evap then the compressor is good, too. Checking both would be the best way. If you're using just the temp at the service port then that doesn't give you an accurate idea of what's boiling off in the evaporator.

[gravity]

that is why it is important to check temperatures at the evaporator coil. if you have a good installation you should not exceed 3psi on the suction side.

[hvac wiz 79]

Yup...$300 plus shipping if you order from Canada...so 340 plus the cost of hoses, which you are going to buy with any digital set anyway.

My ak900 with 5ft. hoses with a ball valve on each hose cost me roughly $430....compare that to what the supply house wants to charge for the Testo 550...$387 with no hoses.

trutech tools . . ak900 for $269.80 delivered to my front door 3 days after ordering

[derb]

Not trying to start a war here, but why get digital gauges? I know everyone has their preferences, but digital gauges seem like total overkill to me. I could buy a bag full of other quality tools for the price. Maybe I'm missing something -- do they do something that a regular gauge doesn't do or are they just easier?

If I banged my analogs half as hard as I feel comfortable banging my digitals, I think I would be buying one if not two replacement gauges for my manifold. The reality is that sets of digitals are more rugged than what we have been using, analogs. The replacement cost of gauges that wear out or get bumped out of calibration is what makes digitals cheaper, or at least equivalent over the long run. Accuracy is way better than your standard class b gauge. Couple that with the fact that taking your superheat and subcooling readings are so easy to take, I do it on every system I hook up to. It's easier than putting the hoses on. I can do the math the manual way, but if your just getting started you'll have to buy a temp probe and you only get as many readings as you do the math. Once you're spoiled by real time readings, you won't want to go back.

On systems that I install I put a suction fitting next to the evaporator. Some of the systems have 50 to 100 ft line sets. If the pipes are sized right the pressure doesn't change by more than a few psi. Engineerdave is right about the compressor superheat. It has to be within certain limits. Some recommend between 20-30 at the compressor.

Dan

[AStudent]

trutech tools . . ak900 for $269.80 delivered to my front door 3 days after ordering

Nice....even though I was roughly 70 dollars more expensive in my purchase, it was still cheaper than buying Testo or even JB at the supply house.

[Furlo]

I really think the sman3 is the best deal out. Now I use my brute for back up.