Originally Posted By: jfarsetta This post was automatically imported from our archived forum.
My question is whether using gauges would be considered invasive or non-invasive. We’re primarily performing non-invasive inspections. I also agree that I believe that the majority of HIs dont own gauges or know how to use them correctly and safely.
With the dangers, and fines associated with freon release into the atmosphere, who would risk it? And, with the HI liable for any damage or screw up to working systems, again... who wants to risk it?
And, I dont believe that 30 minutes is too long. I want to hear that unit after it's been on for a while.
-- Joe Farsetta
Illigitimi Non Carborundum
"Dont let the bastards grind you down..."
Originally Posted By: kluce This post was automatically imported from our archived forum.
jfarsetta wrote:
My question is whether using gauges would be considered invasive or non-invasive. We're primarily performing non-invasive inspections. I also agree that I believe that the majority of HIs dont own gauges or know how to use them correctly and safely.
With the dangers, and fines associated with freon release into the atmosphere, who would risk it? And, with the HI liable for any damage or screw up to working systems, again... who wants to risk it?
And, I dont believe that 30 minutes is too long. I want to hear that unit after it's been on for a while.
I don't believe that 30 minutes is too long. I'm just saying that you can tell everything about an air conditioner within the first 5 minutes. If the compressor or fan motor or condensing motor isn't going to work, it's not going to work. If you do use gauges, it normally takes a minute for the pressures to be at the proper pressure. That means the freon has absorbed the heat it's going to and no more. The suction side of the gauges indirectly tell me how much cold air is going into the house by tell me how much heat the freon is picking up. This works basicly the same with a heat pump.
 I can think of one good reason for having the AC run for a half an hour. If its hot in the house during the inspections. lol
O yes, I talked to an inspector around here today and we were talking about a few things. He told me that anyone has to wait 3 days of 65 degree weather to check an A.C. unit. This is wrong. There are differant thoughts out there but as long as it's 65 degrees, even if it only for the 30 minutes that your inspecting the A.C. There is no chance of anyone damaging the A.C. and still can be checked with guages. It gets hard to check for proper charge under that temp. I never heard of that 3 day thing so I hope it was just him.
Originally Posted By: kluce This post was automatically imported from our archived forum.
The law on releasing freon is that you can not do it on purpose. Even the best freon guage hoses releases a little freon when taking them off the A.C. unit.
Puting gauges on an A.C. unit is simple and tells you a lot. No differant that taking a cover off the furnace or A.C. unit. There are tricks to check for proper freon levels that I'll let anyone know if their interested. Just let me know. It works on any A.C. or heat pump Unit but not on Heat pumps during the winter.
Originally Posted By: lfranklin This post was automatically imported from our archived forum.
What does the tempture drop tell you other than efficiency
Is it different for different brands of units
I've heard of 12-15,14-18,15-20. All came from reliable HVAC contractors.
Are they just one standard 
Originally Posted By: kluce This post was automatically imported from our archived forum.
I was taught in tech school that 16 to 21 degrees taken at the return drop and on the trunk line next to the furnace. 15 to 20 is just as fine. When the furnace is install, the blower is sized for the A.C. If the blower is sized to big. The blower might have to be slowed down; if sized to small there isn’t much that can be done but to make sure the blower is on the high speed terminal. This is beyond the standard of course but something to know.
It's the same for all furnaces. The temp diff for a furnace is on the furnace itself. Some have 35 degree rise and others have more or less. That is something a HVAC person checks but I think temp drop for A.C. is for HVAC person also.
My opinion is worth as much as they pay me. Which is nothing at times.
Originally Posted By: Blaine Wiley This post was automatically imported from our archived forum.
For what it’s worth, I was taught in HI school to take a return/supply split and look for between 15 & 20 degrees. The correct answer on the NHIE is 14 to 22 degrees. I take the split on all inspections as it is a non invasive visual aid. But then, I also check the amp draw on electric strip heaters, so go figure.
Originally Posted By: nstone This post was automatically imported from our archived forum.
I inspected a home recently where the condensing unit, evaporator coils and air handler were in one huge box on the slab next to the house out back. It was a Rheem unit. I had never seen this before and was perplexed after going all through the attic looking for the air handler. Anybody else running in to this kind of unit?
I look for a 14-20 spread at the diffuser and return.
Originally Posted By: Robert L Dean This post was automatically imported from our archived forum.
It’s interesting seeing so many varying opinions. One thing I do agree about is,checking pressures is invasive.That should be left up to EPA certified air conditioning technicians.
There is a way to tell if the heat pump is functioning normally in cold temperatures.My rule of thumb is taking temperature measurements at the suction line outside in heat mode. The suction line should be at ambient temperature plus 100 degrees.This is not 100% but at least you can tell if it is working right.There should also be cold air blowing out of the condenser.
Also it takes more than 30 minutes sometimes for enough frost to build up on the outdoor coil in order to check if the heat pump is going to innitiate defrost.This is the number one reason for a heat pump failures in the winter.
Originally Posted By: Blaine Wiley This post was automatically imported from our archived forum.
Neal,
If you are in the SW FL area, you will be running into these package units often. We have developments around here in Port Charlotte, North Port and others where almost every house is built with them. Some have strip heaters and some don't. Just perform your normal HVAC inspection on them.
Robert, since you arent listed as a member, are you an HI or an HVAC tech? What part of FL are you in?
Originally Posted By: Robert L Dean This post was automatically imported from our archived forum.
I am actually a little of both. More of the latter. I am learning to be an home inspector.With great message boards like this, I can really learn a lot.
I also wanted to add, the original post was about compressors sweating. This is common on very hot and humid days, but can also indicate the system is overcharged.
I look for a 14-20 spread at the diffuser and return.