Central AC

Page 2 of 2  
On 4/12/2011 10:09 PM, Jeff Thies wrote:

Jeff, if you were close enough to my area, I'd be glad to show you how to do the installation because I believe you have the ability to absorb and retain the information and experience. Bright enough folks who appreciate the intricacies of some of the technology around them a few and far between in my experience. ^_^
TDD
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sorry man, but this is one where you are in over your head...
EPA requires a license to buy refrigerant to charge the system, the supply house WILL NOT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Call a pro, you are in over your head already. Do you have a vacuum pump? Do you know how to evacuate the system? Do you have a license to buy the refrigerant?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 4/12/2011 6:09 AM, Ed Pawlowski wrote:

Yes, it's in the post. It's an old RobinAir monster.
Do you know how to evacuate the system?
Of course.
Do you have a license to

Yes. Have had for years.
I've just never done it. I've done auto air, but of course the oiling, pump et all are different. I have no real problem with the concepts, with an expansion valve unit you are setting the subcooling to make sure it is all liquid going into the expansion valve. I think on my unit it is 12F of SC. Superheat should be constant. You just read the temp off a PT chart and see where you are from actual.
I figured this would be easy. I'm sure it was all working before the outside unit got stolen, so it doesn't need to be flushed. It's only 6' to the evaporator, so no adjustments or oil traps needed. The system is empty, so no recovery needed. The furnace end is fine, so no worries about the duct work and blower. I figure 2 tons is enough. It's not like I want to go in the HVAC business. I just want to get AC in.
Obviously everyone thinks I'm in over my head, but I'm not uncomfortable with being there. I used to think you needed a pro to rebuild an automatic transmission or an engine, and those weren't hard.
Is there something that makes this so difficult that I'm missing? Do I really need a pro?
Now plumbing, that's hard.
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Given those measurements, I'd bet the line size you have is 3/4" and 3/8" which are very common. Regarding the joining method, if you goodle a bit you'll find lots of debate on the subject. The pros mostly braze, but there are some that use #8 and swear by it.
The folks who make the Silverbrite #8 have done demonstrations where they put both an AC braze joint and a joint soldered using #8 under test pressure until they burst. The brazed joints always fail first, at a lower pressure, because the high brazing temp weakens the copper. So while the braze alloy itself is stronger, the net result is #8 performs better.
The other MAJOR issue is if you braze, you need to have the lines filled with nitrogen to prevent oxidation from taking place and producing crud inside the lines. Which presents yet another problem for the DIY. With #8 and the lower temps, that doesn't happen, at least not to the extent that it's a problem. Personally, I'd use the #8.
However, all in all, you may be better off just hiring someone with all the right eqpt to do the job. Especially since it's a rental and tax deductible.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 4/12/2011 9:49 AM, snipped-for-privacy@optonline.net wrote:

#8 it is. I've soldered up 1" hard copper with this so I think I can do up the smaller stuff.

$500 seems to be the price for almost anything, except hooking up thermostat wires which is $200. I'm resistant to that.
I may track down an old buddy to fill it or I may just try it myself. I figure I'll check the superheat on the way up to see if there is a fault somewhere. With a THX I can't see where I can really damage anything.
I'll bolt in the unit today. Bought some 10" 1/2" bolts to go through the block wall foundation and a 2 x 4. Have some stout angle stock to bolt on that and rest on the top edges of the unit. Some snake eye screws into the cover and I think that will be enough to discourage the AC recycling business. When I was looking at houses I saw exactly one that still had the outdoor unit. Cages don't seem to be much of a deterrent.
Thanks, Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Consider adding a phony (or maybe real) security camera high up on the wall. Harbor Freight and others have some that look very authentic. Some wire strung around the perimeter on BIG insulators might work, too.
Joe
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I sometimes like to try doing things on my own -- partly just for the fun and adventure of it, and partly as a way of learning how various projects are done. This one, however, would be WAY out of my league. You're a brave soul for trying this one even if you do have automotive AC experience etc.
Since it's a rental property (meaning you are a landlord/investor), have you considered seeing if there are any "REIA's" (Real Estate Investor Associations) near you that you could join? I own some rental properties and belong to a REIA where I am located and one located in the State next door. By being a member of both, I can easily post questions to fellow members about where to find a reasonable HVAC person who may be willing to do a slightly unusual but small job like this at a reasonable cost. If you mention where you are located, I could check to see if I could find a REIA near you. Or, you could check some websites like this one: http://mynationalreia.com/clubportal/795files/directory.cfm?clubIDy5&pubmenuoptID 912.Good luck.P.S. You wrote yesterday that you'll be trying this today. Did you try ityet?Jeff Thies wrote:> I'll be putting in the outside unit (condenser) at the rental> tomorrow, the lines were cut back near the A coil, but there are a few> inches to work with. I've never done this before.>> The outside diameter line is .733" and .383", I'm thinking that must> be 5/8 and 5/16, is that right, or is that 3/4, 3/8 OD?>> What should I solder that with and what kind of coupling? I've got> some Stay-Brite #8 (and a map torch). Will that work, or would> something else be better or easier.>> The outside unit is R22, Goodman CRT24-1A. Is that any good? The> house is 900SF.>> I suppose since the A coil is perhaps 15 years or so old, that it> will be fine with that. Is that right?>> I'll need to pick up some charging gauges, I have an old vacuum> pump. I don't have a thermocouple temp gauge but I do have an IR> thermometer and some old chemistry thermometers. I, of course, want> to stay on this side of slugging the compressor. How should I go> about charging this? I think this has an expansion valve (but am not> positive), so that would be sub cooling.>> Any hints or such? Pointers or resources?>> What about R22a? Something else?>> On another note, I have friend whose central AC hasn't worked for a> couple years. Something funky where they have to rewire it for either> heat or AC. Not much money there and she had someone out to look at it> who said it was $200 job. Might as well have been $2,000.>> So I had a look at this, the furnace is in the attic, man it was hot> up there! No voltage at the thermostat. The thermostat wires went to a> board with two relays on that with wires running out to the outside> unit and some other wires that were not quite hooked up to the> furnace board, a couple inches short of being screwed down. I suppose> that is a $200 repair...>> Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jeff Thies wrote:

Oops, my last post didn't come out correctly. Here's a re-write:
I sometimes like to try doing things on my own -- partly just for the fun and adventure of it, and partly as a way of learning how various projects are done. This one, however, would be WAY out of my league. You're a brave soul for trying this one even if you do have automotive AC experience etc.
Since it's a rental property (meaning you are a landlord/investor), have you considered seeing if there are any "REIA's" (Real Estate Investor Associations) near you that you could join? I own some rental properties and belong to a REIA where I am located and one located in the State next door. By being a member of both, I can easily post questions to fellow members about where to find a reasonable HVAC person who may be willing to do a slightly unusual but small job like this at a reasonable cost. If you mention where you are located, I could check to see if I could find a REIA near you. Or, you could check some websites like this one:
http://www.reiclub.com/real-estate-clubs.php .
Good luck.
P.S. You wrote yesterday that you were going to try this project today. Did you get to try it yet?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.