[Dixon12]

Had trouble with an ancient AC unit, more about that here: http://www.diychatroom.com/f17/ac-coolant-leak-possible-diy-diagnose-403801/

Looks like it's worth to replace rather than try to repair. One local guy gave me a price that's way high ($4,300+ for 13 SEER 2.5 ton unit). Still waiting on pricing from a couple others, but in the meantime was wondering if it is possible/allowed to install yourself. I see 14-15 SEER 2.5 ton units sold online for $1,000-2,000 delivered.

So how difficult would it be to hook up? Any special consideration? Tools?

 

[beenthere]

You need a recovery machine and tank to remove the R2 from the old system.

Torch and brazing rod(or stay brite 8) to braze or solder in the new system. Electrical and sheet metal tools if your duct work is sheet metal.

 

[roughneck]

Vacuum pump, recovery machine with bottles, nitrogen, torch, flow meter for nitrogen purging, nitrogen regulator, sheet metal tools, gauges, micrometer, and electrical meter to name a few. Also an EPA card to handle the refrigerant. And someone to pull an install permit for you.
And your units performance, reliability and efficiency depends on how well it was sized, installed and commissioned.
That price isn't that high. You don't want to race to the bottom. A lot depends on how skilled the guys are installing the equipment.

 

[mikegp]

Would it be possible to do the install yourself and then just have a tech correctly fill the system? I'm sure they won't give you any warranty or anything, but it could save you enough to make it worth it. On the other hand if you mess something up it might cost you more in the long run. I've toyed with installing my own units once my current ones give out. Haven't made a decision yet, though it definitely looks doable with a little research.

 

[Dixon12]

So I'm in very early stages of researching this, but as of now here's how I see this process.

Say I buy something like this: https://www.acwholesalers.com/Goodm...=cat1010&mainCat=&subCat=&trail=15452:2.5 Ton

~$1,700 for 15 SEER AC unit delivered. It says it's already filled with refrigerant.

So the outdoor unit is basically plug and play. The way I have it now, the indoor part of the system sits on top of gas furnace. I haven't looked into how it's all connected, but would that be something that's plug and play as well, then connect the pipes between indoor/outdoor units, or is it generally way trickier than that?

 

[rjniles]

Don't know if the are still available but back in the 70s I bought a system from Sears. Precharged compressor, line set and furnace A coil. Installed A coil in furnace plenum and connected to outside compressor with line 25' line set.

 

[roughneck]

No, it is not plug and play. The outdoor unit is charged for up to about 15' of lineset. The old unit must be reclaimed in accordance with federal law. Then it must be removed, the new unit brazed in and properly wired, and the lineset pressure tested for leaks. Then it must be evacuated and charged per manufacturer specs, usually by subcooling with adjusted superheat.

 

[BayouRunner]

No offense but I won't work on those installed. I feel
Like I am my license on the line. The things I see when a homeowner installs are not good.

 

[zolakk]

I also thought I read somewhere that a lot (if not all) manufacturers will void or greatly shorten warranty if install is not done by a licensed pro so there is that to consider

 

[roughneck]

I also thought I read somewhere that a lot (if not all) manufacturers will void or greatly shorten warranty if install is not done by a licensed pro so there is that to consider

Some will completely void the warranty. Others will not but its like pulling teeth to claim something wrong.
Goodman has such a horrible reputation, because so many DIYers and hacks but their equipment and make a mess of it. Then the equipment gets blamed for a crappy install.

 

[yuri]

There are no precharged linesets and units anymore. The Canadian Keepritre co. made them and sold them under the Sears brand in the 70's and early 80's.

You can DIY and have a Pro start the unit and adjust the freon level and then apparently Goodman will give you a parts warranty. You could even hire one to remove the old freon.

However installing a AC is quite complicated. You have to be good at welding with silfoss and not burn or damage the service valves or have leaks. The lines have to hold 300 psi or more. You need to purge nitrogen thru them while welidng.

I have been talking to DIYers here for 10+ yrs and lots have welding problems or leaks later and regret they ever did it. The you may as well bend over and let a Pro take care of the mess and boy will they charge you top $$ for that. They see it as revenge for stealing their biz and profit margin. Not going to debate that but it is reality. I am sure plumbers and auto mechanics etc do the same.

 

[crabjoe]

Do you really want to spend the $$$ to buy all or most of the stuff below?

Acetylene tank, torch, and regulator.
Nitrogen tank, regulator, and flow indicator
Refrigerant scale
micron gauge
recovery machine and recovery tank
hydraulic swagging tool
sheet metal tools
brazing rods
EPA class and test
clamp on amp meter
multimeter
temp meter and clamps
monometer and probes
manifold gauge
vacuum pump
extra hoses and fittings
a 25lb tank of R410a - There's a smaller size but price wasn't much different.

There's more stuff, but I can't remember them all off the top of my head. I spent about $2 grand in tools/equipment because I bought all new. And it took months to get the tools and equipment because I was looking for sale items. Believe me good accurate equipment isn't cheap.

That's some of the stuff I bought to do mine as a DIY project.

Now I need to install a hard start kit... which is pretty much straight forward.. I picked one up, the 521 compressor saver, but I'm a bit lazy when I get home from work.

 

[beenthere]

There are(or were as of 3 years ago) units that come with precharge condensers, coils and line sets. However, these are/were mobile home split A/C units, not intended for standard construction home use. And were often only sold to MH dealerships.

 

[Habeed]

Dixon, I'm in a similar boat. What I've decided to do, after watching videos on it, is to install a series of "ductless mini-splits". Each one of these is a prepackaged system - precharged with refrigerant. They come in higher SEER ratings than ducted systems, some models are cheap, and the extent of the A/C install is you drill a big hole in the wall, shove the 2 refrigerant lines, a bundle containing the power and thermostat wires, and the condensate drain line through the hole.

You screw the wires down to the terminals and you put some special sealant that makes the flared refrigerant connections unlikely to leak on the threads. You tighten the threads, connect a vacuum pump to a port, and run the pump about an hour. You're supposed to nitrogen test but a cheaper way is to just see if it holds vacuum on a sensitive micron gauge. If it does, you're probably good to go.

In your case, since it's expensive to remove your old system, you could just leave it in place. Install one of the minisplits near the old outdoor condenser and use the same outdoor electrical disconnect box. (just run a new whip to the new minisplit condenser. Don't forget to replace the breaker with one of appropriate ampacity). The other one would require a new wiring run.

Tools needed :

1. Drill
2. 2 3/4" saw bit
3. Screwdrivers and wrenches
4. Vacuum pump adapter
5. Vacuum pump

You can borrow the pump from Autozone for free.

The most difficult part is if you don't already have an electrical connection for one. Also, since they are ductless, you'll need several minisplits to replace a large central unit. For a 2.5 ton, you'll probably need 2 minisplits, placed strategically for good air flow.

Advantages : 1. Each unit is modular, so if one fails, you still have some A/C or heat. 2. SEER ratings about 50% higher than all but the most expensive central systems. 3. They are a prepackaged product you can repair more easily than the big units. 4. They heat via heat pump, which saves you money or costs about the same as gas in most climate zones. 5. You only pay to heat/cool the rooms of a house you actually use. 6. You don't lose 20-40% of the energy in ducting losses, which apparently makes many ducted systems significantly less efficient than their nameplate justifies.

Disadvantages : The A/C guys, for whatever reason, charge a fortune for minisplit installs relative to their cost. If you wanted a single 5 ton unit, they might install it for 4-5k. Each minisplit costs 2k-2.5k installed, which is bad if you need 4 or 5 of them instead of a 5 ton. I don't think the labor of a minisplit install justifies the price tag, but I'm not an HVAC guy, so dunno. These units use inverters and so they are pretty complex, dependent on several circuit boards and microprocessors that can fail.

 

[roughneck]

Minis are a fine idea, providing you get a decent name brand. Those online knockoffs are junk, usually provide very little support and can wind up being disposable.

 

[raylo32]

DIY certainly is possible depending on where you are coming from in knowledge and mechanical skills. Also helps to spec new equipment to replace old in kind including refrigerant line connection diameters, coil dimensions, the location of the refrigerant lines into the coil, etc. That way you have no sheet metal work or need to do any rerouting or adapting refrigerant lines. Also if you have a big leak you probably won't need the recovery machine. Might not be anything in there to recover.

 

[Thurman]

I've read through this entire thread and it seems to me one important factor is missing: Is the unit needing to be replaced a split type system or a package unit? Since buying my house in 1990 I have had to replace two (2) package units. The original unit that was on the house, and last March I replaced unit #2 with a newer package unit. Where I live one cannot buy a system such as this as local HVAC rules will not allow home supply centers to sell them, only HVAC distributors. It really helps to know someone in the A/C business. On these package units there are no lines to change out, so no special tools needed. Just disconnect the electricity, disconnect the sheet metal for the supply run and the return run and slide the new unit in attaching the sheet metal runs back together and wiring it up. It comes pre-charged also. So IF the OP has a package unit the he/she may be able to do this.

 

[Paul.le]

So I'm in very early stages of researching this, but as of now here's how I see this process. Say I buy something like this: https://www.acwholesalers.com/Goodman-Air-Conditioner/GSX160301-ASPT30C14-2-5-Ton-13-SEER-Air-Conditioner-Split-System/32700.ac?catId=cat1010&mainCat=&subCat=&trail=15452:2.5%20Ton ~$1,700 for 15 SEER AC unit delivered. It says it's already filled with refrigerant. So the outdoor unit is basically plug and play. The way I have it now, the indoor part of the system sits on top of gas furnace. I haven't looked into how it's all connected, but would that be something that's plug and play as well, then connect the pipes between indoor/outdoor units, or is it generally way trickier than that?

if you already have gas furnace you do not need air handler

 

[crabjoe]

if you already have gas furnace you do not need air handler

I never looked at the link... You're correct he won't need an air handler, but he will need a new coil... preferably a cased coil.

 

[Paul.le]

I never looked at the link... You're correct he won't need an air handler, but he will need a new coil... preferably a cased coil.

you are correct. He need either 14" or 17" cases A coil that fit the existing furnace