Originally Posted By: cbottger This post was automatically imported from our archived forum.
Jerry Jerry
If you are going to ask for a simple yes or No I would in all honesty have to say No it is not unrealiable. If I was limited to only one item on a inspection sheet It would be the delta T but we are not. Its been nice. And yes I agree with the last post we have gone to deep for Home Inspections
– Don’t argue with an idiot someone watching may not be able to tell the difference.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
cbottger wrote:
Jerry Jerry
If you are going to ask for a simple yes or No I would in all honesty have to say No it is not unreliable. If I was limited to only one item on a inspection sheet It would be the delta T but we are not. Its been nice. And yes I agree with the last post we have gone to deep for Home Inspections
Charley, Charley, Charley,
You contradict yourself.
cbottger wrote:
If you are going to ask for a simple yes or No I would in all honesty have to say No it is not unreliable. If I was limited to only one item on a inspection sheet It would be the delta T but we are not.
The TD is not unreliable unless it is limited to that one item, then it would be. Good so far (although I disagree with your base supposition that it is not unreliable).
cbottger wrote:
And yes I agree with the last post we have gone to deep for Home Inspections
So, delving beyond the TD is too deep for home inspections? I know, I know, you worded it differently, but in agreeing with the other post that this thread was getting in too deep, you leave open the issue as to what "is not too deep", and that is taking TDs only, or 'basically only'.
That means, like many HIs do, to take TD only, or TD and a quick glance at the unit or 'basically TD only'. It happens. More than you think. And you are telling them that TD is not unreliable. Which is just what they want to hear.
"I take a TD. I look for a good TD of 14-22 degrees. If I get a good TD, the system is working properly."
Originally Posted By: jpeck This post was automatically imported from our archived forum.
cbottger wrote:
Jerry
I have a 9:00 am this morning and when I have some more time I will give you all of the steps I complete when checking an A/C unit
That's not what is being asked or discussed.
What is being asked is why you think just taking a TD is reliable.
You have yet to answer that. No qualifiers, no other conditions, just taking the TD. Reliable or not. That is a simple yes or no answer. If you can't answer that with a simple yes or no, I take it the must mean 'no, not reliable by itself'.
Not asking what *YOU* do, or what *I* do, but that a TD is, or is not, reliable. Plain and simple. Many HIs do the TD thing. Reliable or not?
Originally Posted By: cbottger This post was automatically imported from our archived forum.
Jerry:
You are getting testy??
I will answer your Question. Delta T is Reliable (Yes) on Its own.
Jerry If you call an A/C company to come repair your A/C and the inside of your home is 75 degrees and you have 55 degrees being discharged from the supply registers and it is blowing the kitchen curtains. Do you suppose the A/C tech is going to ask you if he can check to see if the A-coil is blocked.
-- Don't argue with an idiot someone watching may not be able to tell the difference.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
cbottger wrote:
Jerry:
You are getting testy?? 
Nope, just making sure you get specific, which you finally did.
cbottger wrote:
I will answer your Question. Delta T is Reliable (Yes) on Its own.
Then, you are incorrect. The TD tells you nothing on its own. Any a/c service tech will tell you that there are many, many things which can, and do, affect the TD, and that, by and of itself, the TD does not tell you anything.
cbottger wrote:
Jerry If you call an A/C company to come repair your A/C and the inside of your home is 75 degrees and you have 55 degrees being discharged from the supply registers and it is blowing the kitchen curtains. Do you suppose the A/C tech is going to ask you if he can check to see if the A-coil is blocked.  
You can have a mostly iced over coil and be blowing enough air around it (I know, air should not be blowing AROUND the coil, but it does when the air tries to go someplace), that you get a decent air flow, and the TD will be high, or within range, depending on how much air an dhow much ice.
I've had TDs of around 55, 85 degrees in the house and cold air blowing off a iced over (32 degree) coil. Yeah, you got a TD of 32, but that means nothing by itself, it could be caused by many things.
How about a little less ice on that coil, and a little more air flow, now the TD drops to 22. Does that mean it is good? No way.
Originally Posted By: cbottger This post was automatically imported from our archived forum.
Jerry hope you are in a better mood.
I was taught 40 years ago that the very first thing that a A/C repair person does when coming onto a job is to 1.Put on the gages. 2. Check for power and start the unit if it is not an electrical problem. 3. If the unit starts GO CHECK THE TEMPERATURES. 4. Check the air flow.
As a HI or the largest % of HI's do not have the option of the first two steps. It is very hard to take the temperature coming out of the duct with a hand held thermometer and not know if their is air flow. Lazer gun different story.
Your post stated many times that TD or Delta T is meanlingless that it tells you nothing. I can say the same thing about air flow it means absolutely nothing if it is not cold. Bottom line. Some of your earlier posts stated that you do not always take your TD and then in you last post you stated that you do take TD on every unit "which is it"
You also implied that there were inspectors out there that just stuck a thermometer in a register recorded the temperature and that was it. There very well may be but the attorneys for the consumer will eventually put those inspectors out of business.
I stated that Delta T would stand alone and it will if that is the only option you have but it is not. You have never seen a post of mine that recommends to anyone to simply take the tamperature and walk away.
I alway perform above the standards of practice for this state and recommend that to any other inspector. 
-- Don't argue with an idiot someone watching may not be able to tell the difference.
Originally Posted By: cbottger This post was automatically imported from our archived forum.
Sorry to inform you Jerry air does not pentrate around or thru a complete block of ice on a coil. anyone with any experience just feeling the air flow from a register or I should say lack of it would know that there is a problem. The light bulb should come on. Its call static pressure in the return because the air has no where to go. If you had 32 degree air being discharged from a register the light should come on you have a problem don’t trouble shoot its not our job.
– Don’t argue with an idiot someone watching may not be able to tell the difference.
Originally Posted By: cbottger This post was automatically imported from our archived forum.
More for Jerry:
Yes the Delta t can be affected by most any factor. You can adjust it up and down with the freon charge. You can adjust it with a TXV with the speed of the blower or a restriction in the line set or cap tube will change the delta t. and it will not be normal. if you have 15 degrees between supply and return air temperature with sufficient air flow to cycle the unit you do not have a problem with the unit and if you do not beleive this you should find your self another A/C tech to talk to as someone is blowing smoke.
-- Don't argue with an idiot someone watching may not be able to tell the difference.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
cbottger wrote:
Jerry hope you are in a better mood.
Apparently I am getting to you, you must be trying to place your irritation onto me. I am fine, sounds like you are not. I've disagreed with better men than you and survived okay.
cbottger wrote:
I was taught 40 years ago that the very first thing that a A/C repair person does when coming onto a job is to 1.Put on the gages. 2. Check for power and start the unit if it is not an electrical problem. 3. If the unit starts GO CHECK THE TEMPERATURES. 4. Check the air flow.
BINGO! Now you are getting somewhere. YOU took TD as PART OF your other checks. NOT as a stand alone test, which is where I am struggling to keep you, because you are always wondering off point.
cbottger wrote:
As a HI or the largest % of HI's do not have the option of the first two steps. It is very hard to take the temperature coming out of the duct with a hand held thermometer and not know if their is air flow. Lazer gun different story.
Air flow in and of itself also does not matter. You could put your hand up there and feel air flow, feel that it was cold, why even take a TD if that is what you are looking for? Does it have the proper air flow? Don't know. Don't really know after you've looked at the coil and see it is new and clean, but at least then you can make an assumption that the coil is not causing a restriction, could be the fan speed is off. As I keep saying, too many things to check besides TD which affect TD, one of which is your air flow. Air flow goes up, TD goes down, Air flow goes down, TD goes up, (Assuming everything else remains the same and that there is refrigerant in the system and the compressor is working),
cbottger wrote:
Your post stated many times that TD or Delta T is meanlingless that it tells you nothing. I can say the same thing about air flow it means absolutely nothing if it is not cold. Bottom line. Some of your earlier posts stated that you do not always take your TD and then in you last post you stated that you do take TD on every unit "which is it"
Huh? If you would, please point out where I said I take a TD on every unit. No wonder we are having such a hard time communicating, I type what I say and you make up what you want me to have said.
cbottger wrote:
You also implied that there were inspectors out there that just stuck a thermometer in a register recorded the temperature and that was it. There very well may be but the attorneys for the consumer will eventually put those inspectors out of business.
I disagree. The attorneys will only get to a few of them, there are hundreds or thousands of HIs out there who only do that, because they are in a time crunch and were taught that the TD is reliable, just like you are teaching them. IF the TD is reliable, in and of itself, why is there a need to do more? According to you, there isn't, so they don't. YOU DID SAY that TD was reliable, right?
cbottger Posted: Apr 26, 2004 11:05 PM Post subject:
I will answer your Question. Delta T is Reliable (Yes) on Its own.
cbottger wrote:
I stated that Delta T would stand alone and it will if that is the only option you have but it is not.
Dang, there you said it again, didn't have to go back and copy the other one. 
cbottger wrote:
You have never seen a post of mine that recommends to anyone to simply take the tamperature and walk away.
I have said that was all YOU did, only that you are telling all HIs that is ALL THEY NEED TO DO, because, as you have repeated, TD is reliable. That is what I am discussing and disagreeing with, so you do not leave other HIs thinking that all they have to do is take TDs, because TDs, of and by themselves, ARE NOT RELIABLE.
cbottger wrote:
I alway perform above the standards of practice for this state and recommend that to any other inspector. 
As I keep saying, it is not about what YOU DO, it is about what YOU SAY. And you keep saying that TDs are reliable, in and of themselves.
TDs are not reliable, in and of themselves or otherwise.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
cbottger wrote:
Good Morning Jerry Is you are on line early this morning.
Here is a quote for you
A man convinced against his will is of the same opinion still.
Not early, I check it before I head out, which I am doing in about 5 minutes.
Not trying to convince you as much as to offset your incorrect information to the other HIs reading these posts. You can continue to believe that taking TDs is a reliable indicator of the system, I just do not want others to make that same mistake. This forum is used to exchange information, and we all learn, sometimes we learn 'good information' and sometimes we learn 'bad information'. Saying that taking TDs and using them as a reliable indicator of the system's condition is 'bad information'. That's all I am trying to get across to everyone else.
Here is another old saying:
You can take a horse to water, but you can't make him drink.
Look down, the water is right there, you don't have to die of thirst.
Originally Posted By: poffenberger This post was automatically imported from our archived forum.
Quote:
"I take a TD. I look for a good TD of 14-22 degrees. If I get a good TD, the system is working properly
.
Wow if I found a 14 or a 22 degree drop I would know that something PROBABLY is not correct. If you want to start splitting hairs, you first need to know the ductwork is good. Then move to how the A/C was installed. Did a good old boy, just purge the system, or did they pressure test it and then evacuate it. When I hear of 14 degree splits that hvac people say are fine. I always would like to invite,, the know it all's,, to pay the utility bill.
Originally Posted By: poffenberger This post was automatically imported from our archived forum.
I don’t mean disrespect towards HI’s or HVAC people. To type a few lines of info on any subject, will not do it justice, and may make the statement sound lacking. I would think most home inspectors ,would take a temp drop, also look at filter, blower, condensing unit, check for frosting, etc… then using reason, could give a " appears to be operating within design limits at this time etc… or whatever, there are way too many factors to give a hard-line answer.
Originally Posted By: cbottger This post was automatically imported from our archived forum.
Jerry:
I am fully aware that we are strangers and have no credibility with each other, but you should really stop getting your information from your brother-in-law or the next door neighbor. There is a place uptown from you called the Library(The Big Building with all of the books) One specifically you should check out wrote by three very credible Engineers with long degrees Called (Modern Refrigeration and Air Condition) by Althouse, Turnquist and Bracciano Page 684 paragraph 16-18 Describes the theory MFG’S use in designing and MFG evaporator coils for different applications There are 4 items that are addressed in designing evaporator coils and they are.
AREA.
TEMPERATURE DIFFERENCE.
THICKNESS OF MATERIAL.
TIME.
Jerry you should really read this book as it will bring you into the real world.
Another old saying Jerry.
Even a blind hog will find an acorn occasionally
You should look a little harder.
-- Don't argue with an idiot someone watching may not be able to tell the difference.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
cbottger wrote:
Jerry:
I am fully aware that we are strangers and have no credibility with each other, but you should really stop getting your information from your brother-in-law or the next door neighbor.
Better than asking the drunk down the street, though.
I have found it difficult to keep you on point. That point being that you say that TD measurements ARE RELIABLE in and of themselves, yet then you always go off point into what else is needed.
You say: a) TD are reliable even when taken alone.
Then you say: b) But you also must check / consider / they also take this into consideration / etc.
IF you truly believe in a), there is no need to go off point to avoid the discussion.
Another old saying "Even a stopped clock is right twice a day." Maybe you should become a 'stopped clock', so you can be right.
You seem to have a real problem keeping on your 'TD readings are reliable.' message. You are always throwing something in which shows I am correct, that TDs by themselves are not reliable, that they need other things for support / backup / etc., so I am not sure what your real point is ... distraction so we forget you said TD reading are reliable in and of themselves?
I'm trying to help you stay on point. Either TDs are reliable in and of themselves (in which case you would not need to supply all the other information which supports me saying they are not), or simply provide the other information and acknowledge that TDs are not reliable indicators of a system in and of themselves.
It's like you keep saying "I can hit this with a stick ball bat.", then you pick up a Louisville Slugger bat to show us. You seem to be missing something somewhere.
The lights on, I can tell from your posts. I'm just not sure anyone's home.
This is getting old, so I will let you carry on if you have that desire or need. I've taken the horse to water, but I am not able to get him to drink.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
Charlie,
So, you agree, then, that TD reading are dependent on other things and are therefore not reliable in and of themselves, but must be taken with a grain of salt and used in conjunction with the other design parameters and conditions.
I believe they also have that on Books On Tape for Special Needs People.
Originally Posted By: cbottger This post was automatically imported from our archived forum.
Jerry:
Yes Jerry I am a special person I have knowledge but no specific needs.
Coils are designed by MFG'S for a specific range of TD's be it low temp, medium temp, or high temp. TD is just a measuring stick that is available to be used by the HI. Supply temp vs Return Temp. Another TD not available to HI's is between the temp of the freon in the coil and the air being passed over the coil. Just another measuring stick.
So according to the book not me, A coil is designed for a specific range of TD and again according to the book TD is # 2 on the list of importance in designing coils. So if the TD is out of range of what the coil is designed for how can you determine performance if you don't know what the TD is and on the other side if the TD is within range how can you say it is not performing.
I am referring to the importance of TD to me and your apparent lack of importance for TD. I am not referring to any other issues such as condition of the air handler, the duct work, line sets or anything else in the total make up of A/C systems as they should be dealt with on an individual bases.
Jerry I gave you the name and author of the book (such a wealth of knowledge) SKILLS ARE WORTH MONEY. How much money do you have. Another old saying
-- Don't argue with an idiot someone watching may not be able to tell the difference.
Originally Posted By: jpeck This post was automatically imported from our archived forum.
cbottger wrote:
Coils are designed by MFG'S for a specific range of TD's be it low temp, medium temp, or high temp. TD is just a measuring stick that is available to be used by the HI. Supply temp vs Return Temp. Another TD not available to HI's is between the temp of the freon in the coil and the air being passed over the coil. Just another measuring stick.
Keeping you on point has become a real challenge.
Here you go again, talking about designing coils and using more than just the TD for checking and determining the systems operation. Nothing you've produced so far has come close to backing up your statement that TDs are, by and of themselves, a reliable indication of the systems condition.
As you have stated many times, in agreement with what I have stated, is that TDs are used in conjunction with other indicators.
A fool and their money are soon parted. (Another old saying.) How much do you have left? (Referring to your "SKILLS ARE WORTH MONEY" quote.)
