three way manifold

three way manifold
Gauges used for testing refrigerant pressures.

Sunday, October 17, 2010

All of The Ads That Google Puts Around My Blog Entries.

Do you see all the ads around this page? There are ads for Sears, Rheem, Trane, various A/C companies and all kinds of things related to air conditioning units, services and installations.

Do me a huge favor, please? Don't click on them or use their services! My company is right here, and we can do all the same stuff for you any of these guys can do. We can probably do it cheaper than them.

If you feel it necessary to click anywhere, click on the link to my website.

You'll be able to learn a lot, and contact me or someone at my company to get the things done that you need done.

I just wanted to offer up that public service announcement.

Wednesday, October 13, 2010

Post Office in San Antonio, part 3

So . . . talking about the same post office I was talking about a few days ago. I thought I'd log back on the next day, but I had cool stuff like the Floresville Peanut Festival come up. I just HAD to go!

Anyways . . . we did all this work to find out what was wrong with that York unit, and learned that the other contractor was right about the compressors being bad. While I was there, I was able to talk the management company into letting me clean the other unit on the premises, and perform basic maintenance.

So the next day I spent about half the day pulling that other unit (it's a Trane by the way) apart and cleaning everything so it would function properly and not leak all over the place . . . pain in the butt, but it was a $600 (for me) pain in the butt. When I got done, I noticed that the liquid line was running cool . . . about the same temperature as the suction line. The liquid line actually carries liquified refrigerant, which is compressed from its gas state, so it's supposed to be warmer than the suction line which carries refrigerant in its gas state. You see, refrigerant cools down as it is sprayed from its liquid state through a metering device into the evaporator coil. Spraying it allows it to form back into its natural gas state, cooling it considerably. Just think of your bottle of Windex that you spray on the windows to clean them . . . or those misters used at football games to keep the players cool . . . or a fuel injector. All of those things vaporize a liquid by spraying it.

Needless to say, there needs to be a perfect balance of refrigerant so it will be liquid going into the home and vapor coming out of your home. If this balance is thrown off, it will damage your compressor or you will notice ice accumulating in your unit. That's why HVAC contractors are hired. We know what we're doing! We have to understand pneumatics, hydraulics, elctricity and plumbing to do what we do. It's not easy, and there are people out there who know more about each of the things we work on than we do. It's just amazing how scentific all this stuff is.

Back to the subject now. 15 ton Trane unit, post office, cold liquid line, suction line freezing up. There was a reason for the last two paragraphs. See if you can follow now. We checked the unit out by actually following the liquid line from where it came out of the wall outside backward to the unit, inside the unit to a filter/dryer that was attached.

Now, do you want to hear something cool? The the liquid line was about 20 degrees warmer going into the filter/dryer than it was coming out of the filter dryer! Based on everything I said in the previous paragraphs, that means something was happening to the refrigerant as it passed through the filter/dryer. It was entering as a liquid, but exiting as a vapor. How the hell could that happen? Well, this is a filter we're talking about here, so it gathers up particulates in the refrigerant as it passes through the filter/dryer. It just so happens that the filter was clogged so much that the refrigerant had to move through tiny holes in the filter to get to the other side. So as it passed through the filter, it was being sprayed through those tiny holes and turned into a vapor as it moved to the other side. That's why the liquid line was so cold when it is supposed to be the warmer line. Remember? When refrigerant becomes a vapor, its temperature drops considerably.

That's exactly what was happening in this situation. We're not sure how long this went on, but that puts back pressure on the compressor, shortening its life, so we needed to get the filter/dryers changed out as soon as possible.

I'm getting tired of typing now, so I'll continue later.

Adding Financing as an Option For a Business.

Recently, I was able to start offering financing for my HVAC company, All Seasons Comfort in San Antonio, TX.

I always though there would be a lot of hoops to jump through in order to get this done, but was amazed at how simple the process was for me. You see, I've tried with a few different businesses to get something like this going, but have been turned away for various reasons in the past, usually because the business I was managing wasn't old enough. That doesn't make a lot of sense to me, because I always thought that the financial institution had to deal with the customer, not me and my business.
It's a ridiculous thing if you think about it.

Anyways, my worries are over on that front. Let's see how this new deal will pan out for me.

Thursday, October 7, 2010

Post Office in San Antonio, part 2

Anyways, we went back to the post office the next day to check the unit out indepth, and learned a lot about how it was built, and why things were where they were.

It turns out that those York units have these sensors on each compressor called "motor protectors". These motor protectors monitor the temperature of the compressors. When a compressor reaches a certain high temperature, the motor protector sends a signal to a relay, which in turn deactivates the 24 volts running to the contactor, in effect killing the power to that particular compressor for 30 minutes, which is long enough for the temperature to drop. The other compressor is able to run this whole time supplying refrigerant to the indoor unit as usual.

It took 5 billable hours to figure all this out! These motor protectors are great, but they pretty much keep a compressor from burning up because they will never let it get to a temperature that WILL burn it up. It can't burn the circuit out and open it up, so it just lets the compressor run for a shorter and shorter period of time until it just runs long enough to heat up (maybe two minutes) and the sensors kill it. It won't blow up, and it will be forever until it actually opens up the circuit.

So, we figured all this out, and learned that the unit hadn't been cleaned in sometime, and that the ductwork had been pinched almost in half so some other crazy HVAC contractor could install an in-duct furnace that was too small for the necessary airflow.

I'll keep going tomorrow about this.

Wednesday, October 6, 2010

Post Office A/C Problems

So I live in San Antonio, TX, and I'm an air conditioning contractor. I get calls from all kinds of people, but one I got this past week probably stands out quite a bit.

Anyways, the first thing that stands out about this call was that it was from a post office rental management company. That's a real estate company that manages the properties post offices use. This particular company manages about 5 properties within a 30 mile radius of San Antonio, and over 600 properties nationwide.

So this guy named Sean calls me from New York or someplace like that. He says he wants a 2nd opinion about what needs to be done with an air conditioning unit that another contractor says needs to be changed out. He told me the other guy advised him it's time to change it out. So I agreed to go check it out.

This post office is off of West Avenue in San Antonio, which is just about a mile and a half from my house. So, I drove on over there to check it out, took my tools out of the truck, hooked up the gauges, took the service panel off the unit, looked up and saw the other contractor walking up to where I was. He seemed just as surprised as me as to why the other guy was there.

Well, we introduced ourselves and started talking about the unit and what's been going on with it. He was a pretty friendly fella, so it wasn't hard to strike up a conversation with him. He told me that he had installed that unit a few years prior, and had another unit on site that he was ready to install since this one had gone down. He said he remembered that the last compressor was on the way downhill, but he couldn't remember exactly what he had diagnosed.

You see, this is an old, 15 ton York unit that has two compressors that work in stages. What that means, is that one compressor is used as a primary, and the other is an auxiliary compressor. The primary runs all the time, and the auxiliary only kicks in at times where the load is too substantial for the primary, or even if the primary compressor overheats. In other words, the auxiliary compressor doesn't work as hard or as much as the primary. Now, I don't know everything about this particular brand unit, so anyone wanting to teach me something can chime in. Well, the primary compressor was supposed to have already gone out on this unit, so it was disconnected, and the unit had been working off the auxiliary unit only for the past few years. Since the unit is already a dinosaur, it would be no surprise if it stopped working at all.

I explained to the other contractor why I was there, and that I had to do my due diligence with the unit, and check it all out. He understood, and kind of went along with me as I checked it out. Well, the first thing I did was to see if I could test the primary compressor for an open circuit. Since it's a three phase unit, I couldn't just ohm it out. The problem was that I wasn't able to test it as open. It came up as a good circuit every time and way I tested it. Well that didn't make any sense to me, so I reconnected it. I then flipped the breaker, and low and behold, it worked!

The other contractor seemed just as amazed as me. He swore that it wasn't working the last time he was there, otherwise he wouldn't have unhooked it. All I knew was that it was working now. So, I left it working, and called the management company again to let them know what I had found. Even though I figured it was one of those things where the other contractor may not have been wrong, I think he felt like someone wanted to blame him, so he quickly disappeared.

As it turns out, the other guy wasn't necessarily wrong. I think he just may have found it very hard to diagnose the problem because of the safety mechanisms York puts on their units. All signs pointed to the compressors being out, but it was almost impossible to verify this with traditional tests. I'll probably give the guy a call and tell him what we ultimately learned so if he ever runs into one of these units again, he'll be ready.

The ultimate problem will have to wait for later though. My carpal tunnel is acting up. I'll finish this later.