10-01-13, 08:51 PM | #1 |
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I am going to install mini split system. Help picking out equipment.
I have never used manifold gauges or vacuum pump. But the rest of the install looks like something I can handle.
Would this work. Air Vacuum Pump with R134A and R12 Connectors Vacuum Pump - AC Vacuum Pump w/ R134A & R12 Connectors how about these gauges? Yellow Jacket 42001 Series 41 Manifold 3 1/8" Gauges: Amazon.com: Industrial & Scientific how about this gauge or do you recommend a different gauge? Fieldpiece SVG3 Digital Micron Gauge (Vacuum Gauge) Fieldpiece SVG3 Easy View Vacuum Gauge - at the Test Equipment Depot Last edited by pinballlooking; 10-02-13 at 05:36 PM.. |
10-01-13, 09:26 PM | #2 |
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That vacuum pump is good for vacuum bagging, but no good for HVAC work. A freezer compressor would be far superior to that. But for about $150 or so, you can get a reasonably good two stage.
For some reason, automotive gauges and residential/commercial gauges are different. You should be able to get a reasonable deal at a local HVAC store. (I got my pair of Yellow Jacket gauges for under $50 at a local store a few years back.) A micron gauge is not a requirement, but it can be very helpful. For a one off, doing a pressure test followed by a triple evac gets it done. You do need some way to purge (if you need to braze) and pressure test, which can be done with nitrogen or CO2. (Propane can be used for purging, but only for the outdoor connections.) Also note that a common propane torch will not work for brazing. MAPP gas works, but the good stuff isn't made anymore. Nowadays, either oxy-propane or air-acetylene works great. (So does oxy-acetylene, but it's especially easy to overheat the braze with it...) If you wait long enough, you might be able to find an oxygen concentrator for cheap on Craigslist.
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10-01-13, 09:32 PM | #3 |
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Ok maybe this pump
3 CFM Two Stage Vacuum Pump Air Conditioning Vacuum Pump - Two Stage, 3 CFM I have a 25% off coupon. |
10-01-13, 09:41 PM | #4 |
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Vacuum 'pump' you show is worthless, do not throw even $15 down a rathole. You need something that will pull down to under 1 Torr, 500 microns preferred. (10 Pa ,5 Pa )
Cheapest one I saw right off on ebay is: Single Stage 3CFM 1 4HP Rotary Vane Vacuum Pump HVAC Air AC A C R410A R134a | eBay micron gauge is good, but you can probably find a used analog one for less $$. Be aware that if you have any type of leak, the micron gauge will always show maximum even though with a small leak the gauge set will show 30" of vacuum. It will also take a few minutes to pump down until the vac gauge shows anything. gauge sets per se are OK, but you will need adapters for R134 to R410A connections, and also for sae 5/16 to 1/4 interconnections. Would be good to get a nitrogen bottle and regulator to do preliminary pressure testing also. Don't forget to get a small quantity of POE oil to lube ALL surfaces of the flares before torqueing. I prefer to pull vacuum for 15-20 min, put dry nitrogen into system at 400 psi and turn off all gauges and let sit overnight. Pressure in the morning should read the 'same' as the previous day - don't forget to calculate temperature effect on pressure. Then pull 500 micron or lower vacuum and hold for a few hours (I do overnight just to make sure) Then just crack slightly open the valves on the outdoor unit, just enough to show a few psi positive pressure - and ONLY then remove the gauge hoses. Now open the outdoor unit valves fully and cap the ports. Good luck. PS: ditto on Mike's comments. I use 15% Ag silphos for brazing, NEVER try to 'just get by' with soldered refrigerant connections. Last edited by mejunkhound; 10-01-13 at 09:44 PM.. Reason: add |
10-01-13, 10:18 PM | #5 |
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An analog vacuum gauge would be worthless for HVAC, except the exotic sealed units that actually measure low vacuums. (But those probably won't be cheap...)
The second vacuum pump you linked is great. Don't bother with POE oil, just get a small bottle of Nylog Blue. Very cheap and use it on every flared connection. As for the best brazing rod to use, Dynaflow is cheap but still easy to work with. You'll want to leave your gauges connected for the initial power up for checking pressures. Once the third stage of the triple evac is over, close off the gauge valves and open the suction side service valve slowly. (Do it too quickly and the oil in the compressor might foam up and get sucked out of the crankcase. Unlikely but possible.) Then open the liquid line valve and start it all up. You'll also want a torque wrench (and a set of open ended sockets) for flare connections and a thermometer for checking superheat/subcooling.
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10-01-13, 10:32 PM | #6 |
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I would just use a standard line set 15’ so I don’t think I should not need brazing rod.
I have a few torque wrenches I also have an Infrared Thermometer. I ordered one Gree 9,000 BTU 27 SEER Terra Ductless system with a 15’ lineset with flare fittings. One Nylog BlueGasket/Thread Sealant. Last edited by pinballlooking; 10-02-13 at 10:34 AM.. |
10-04-13, 08:37 AM | #7 |
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This is the equipment that I am planning on buying. Any comments would be good. If all goes well I well with my first install I will be install a second unit. I want decent (no junk) equipment but try not to over spend. This all will have free shipping.
Yellow Jacket 41780 Manifold w/ 1/4" Fittings, Bar/Mpa, R-410A $57.95 Yellow Jacket 41780 Manifold w/ 1/4" Fittings, Bar/Mpa, R-410A Robinair 15150, 15300, and 15500 VacuMaster Vacuum Pump $136.95 Robinair 15150, 15300, and 15500 1.5, 3, and 5 CFM VacuMaster Vacuum Pump - on Sale at the Test Equipment Depot Fieldpiece SVG3 Easy View Digital Vacuum Gauge $121.95 Fieldpiece SVG3 Easy View Vacuum Gauge - at the Test Equipment Depot |
10-04-13, 07:10 PM | #8 |
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That's a great setup. Add the CO2 or nitrogen tank and regulator and you should be good to go.
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10-04-13, 07:39 PM | #9 |
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I'll add one more hint on the CO2 or N2 bottle.
The bottle and regulator costs are the same for Ar as for N2. If you get argon, the refill price differential for an 80cfm bottle is only about $10 (30 vs 20). With the Ar you can weld aluminum with your wire feed welder (good excuse to buy one if you don't already have one) and you can also drill a hole in the side of old nitrogen filled insulated glass and blow in argon to clear up fogging and increase R value (seal holes with butyl afterwards) |
10-04-13, 07:58 PM | #10 |
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Thanks for looking over the tool list.
http://www.amazon.com/gp/product/B00...F8&me=&seller= Great tip but I already ordered Nitrogen gauges and regulator. The guy that fills my CO2 tanks said he said he will rent me a Nitrogen tank for just the cost of the gas used. I also ordered 5/16 adapter for 410A. My Mini split shipped today. |
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