Author Topic: hooking up whole house A/C condenser  (Read 6321 times)

conpewter

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hooking up whole house A/C condenser
« on: October 11, 2013, 12:44:03 PM »
I'm a pretty heavy DIY guy, bought a foreclosure a while back and have since moved in to it.  The furnace (which is in the attic) is set up for air conditioning but the outside condenser was stolen while it was in foreclosure.  I don't use A/C much, but my wife does some, and I'd want it available when I rent the house someday.

I tackle most things (such as all the plumbing/flooring/roofing on this house) but I have not found a good way to DIY test/fill a 3 ton air conditioning unit.  Any tips ya'll have?


ncornilsen

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Re: hooking up whole house A/C condenser
« Reply #1 on: October 13, 2013, 02:50:28 PM »
You can't.

You can purchase a condenser online, but you loose your warrantee, and will still need to pay someone to install it.. the most you really can do yourself is pour a pad for it to sit on, make sure the wiring is ready to tie into, and get a quote.

I replaced the entire HVAC system in my house, by myself, ran the refrigerant lines, but had to hire a HVAC tech friend to come solder them up, pump the system down, leak check, and fill. 

conpewter

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Re: hooking up whole house A/C condenser
« Reply #2 on: October 13, 2013, 08:55:47 PM »
Hmm, I don't like can't, I'm pretty big on in-sourcing.  I've seen some videos on it, but getting the refrigerant is going to be difficult, but more-so I think vacuuming down the lines and putting in the proper amount.

Even if I outsource it... I've not found anyone that is willing to touch it since they didn't get the commission on me buying through them.  Same as when I did the granite countertops in the last place, since I didn't buy the granite from them, no one would install it for me, so ended up doing that all myself too... good lesson on how to do heavy countertops though :)

ncornilsen

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Re: hooking up whole house A/C condenser
« Reply #3 on: October 14, 2013, 05:26:22 PM »
I should rephrase 'can't':  buying the equipment to do it will cost much more than hiring someone.  Setting amount of refrig in the line can be tricky too.
But, not all is lost:

depending on the brand of condenser, (what is it, btw?) you can find local guys, and use the online price to see if they'll meet you in the middle, if you get it from them. Smaller shops are best for this... big ones tend to thing they're better than working with homeowners.

They might let you pick the stuff up, place it, run the lineset, wire it, and have it so all they need to do is drop by, solder the fittings, pump down and go. My guy charged $300 to solder, pump, and fill my system, and he matched the online price.

Boz86

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Re: hooking up whole house A/C condenser
« Reply #4 on: October 27, 2013, 08:37:33 AM »
Lot's of info over here: http://ecorenovator.org/forum/geothermal-heat-pumps/

May have to dig but just all the DIY info you'll need.

conpewter

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Re: hooking up whole house A/C condenser
« Reply #5 on: November 04, 2013, 10:44:55 AM »
Thank you :)

Glad to hear there are some local guys that might actually take on the project. I'll find out what type of condenser it is when I get home.  Didn't really need the AC this summer (Just ran a window unit sometimes in a couple rooms), but will want to hook it up someday before I sell or rent the place.

tdouglas

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Re: hooking up whole house A/C condenser
« Reply #6 on: November 05, 2013, 09:22:26 AM »
Did the same thing myself at my home (1.5 ton and 4 ton systems), at my rentals, and my office. My first experience involved buying the a NEW 1.5 ton split system from a Goodman wholesaler and getting 1 of 2 willing local installers to install it. They did this without permits and did a pretty messed up job. After that, I was going to have to pay big $$$ to have the system installed properly so I started to research. I ended up buying all of the tools needed to do the job RIGHT and have had my first system running without a hiccup for 3 years now.

To be able to buy or handle refrigerant, you will need your EPA certification. Luckily you can take an online, open-book test to get your EPA Section 608 certification at EPATEST.com. You can also do a free R410 technician test, among other goodies included in the exam fee. I did this, got my card in the mail, then went to my local HVAC supply house and could buy R-22 and R-410a refrigerant. Keep in mind that the open book test is only good for servicing systems up to so many tons and if you want to be 100% legal, you should take the sit-down test for larger residential systems.

Look up the model of your condensing unit and you will find the installation manual online and it will have the calculation of refrigerant based on the length of your lineset (copper tubes). You will need to measure the length of copper tubing and determine if you need to ADD or SUBTRACT refrigerant based on your lineset length.

At a minimum you will NEED to buy:
1. HVAC gauges with hoses (red, blue, and yellow) - about $50 on eBay NEW. Check refrigerant pressures/temperature to determine superheat and subcool.

2. Vacuum Pump - about $120 from Harbor Freight for a 3CFM Dual-Stage Vacuum Pump with 25% off coupon.

3. Nitrogen Tank and Regulator - about $200 from your local Welding Supply store or HVAC supply house. You can get the regulator off of Amazon or eBay as well. Use this to pressure test your system for leaks and also to flow Nitrogen while brazing the copper lines to eliminate chances of oxidation inside the copper which will clog up the factory-installed filters and negate their presence. You will also use Nitrogen in the triple-evacuation process to clean the refrigerant piping before letting the refrigerant out of the compressor.

4. Oxy-acetylene torch setup with tanks --> Harbor Freight has a good kit with tanks - drop off empty tanks at AirGas or HVAC supply house and they give you USED, certified FULL ones. This is used to braze/weld the copper lines.

5. Brazing rod --> Stay-Silv 5 is OK for R410a systems. This is to make any connections in the copper lines. DO NOT USE plumbing solder. You could get by with older, lower pressure R-22 systems, but not with R410a systems. You need the Stay-Silv or similar. Stay-Silv 5 means it has 5% silver, higher silver content makes is easier to work, but at an increased cost. As a newbie, you will go through a lot just practicing, so stick with the 5%.

6. TIG Welding Gloves --> an oxy-acetylene flame is VERY HOT.

7. HVAC Thermometer with K-type Probe --> used to check the outside temperature of the copper tubes to determine subcool and superheat to fine-tune the amount of refrigerant charge you need.

8. Copper lineset if not included with new system. You can also use a special cleaner to clean the R-22 from old linesets out to be used with newer R410A (the only type allowed to be sold nowadays in the USA). I would recommend newer linesets though for piece of mind.
You can search YouTube for 'Dr. Zarkloff' and see how to do some common HVAC work, which will give you more confidence before you hook up your gauges for the first time.

9. Micron Gauge --> used to check vacuum on lineset, you need to hold under 500 microns to say you have a good seal and all contaminants are out of the lineset before releasing the refrigerant.

10. Or get a Fieldpiece SMAN3 Digital Manifold that includes (2) thermometers, digital gauges, and a micron gauge. It is about $300 off Amazon, but you get everything in one package. You will still need to buy some hoses off eBay though. The longer hoses (60in) will take longer to pull a vacuum vs shorter hoses (48in).

I just had laser eye surgery, so I will try to remember to post more later as I have to rest my eyes now.