AC Coil

All
I purchased a cased ac A coil for my furnace and would like to install it with out installing the condensor. The instructions say that it is pressure charged and the pressure should be released before soldering. I would like to keep the pressure in the A coil until next summer when I hook up the condensor.but I'm worried about heating up the furnace with the A coil pressurized. Could I damage the coil? would I allow contamination into the system if I remove the pressure and leave it open to the atmosphere for a year?
you advise will be greatly appreciated.

I would install it as is, do not open to the atmosphere. It has a light charge to keep moisture out. When the final hook up is made, a vacuum should be pulled on the lines, even if they are precharged.

brosnt1 said:

All
I purchased a cased ac A coil for my furnace and would like to install it with out installing the condensor. The instructions say that it is pressure charged and the pressure should be released before soldering. I would like to keep the pressure in the A coil until next summer when I hook up the condensor.but I'm worried about heating up the furnace with the A coil pressurized. Could I damage the coil? would I allow contamination into the system if I remove the pressure and leave it open to the atmosphere for a year?
you advise will be greatly appreciated.

Click to expand...

Do you have a vac pump, a micron gauge, a nitrogen bottle, a decent set of vac&pressure gauges? Do you have any idea what "super heat" is, Do you know how to silver solder or braze? Finally do you have an RSES ticket to handle refrigerant? If the answer to any of the above is no than you need to call a professional.

At a minimum you will require Section 608 Type 2 certification to even work on residental A/C Type 1 allows the purchase of refrigerant in containers over 20 pounds if my memory serves.

Some residential units still use R22 but since it's a HCFC and still depletes the ozone layer we'll see how long that continues since new production will be phased out in 2010 I believe.

From then on only reclaimed R22 will be available and we've seen with R12 that prices WILL skyrocket.

R410a is a popular HFC refrigerant while it doesn't harm the ozone layer it contributes to global warming so it can no longer be released to the atmosphere and must be reclaimed.

However in case you're curious if you could purchase the refrigerant then you would also need the basics:

Here are a few of the must have specialized tools a vacuum pump (proper CFM to evacuate your system), micron gauge to accurately measure the vacuum pulled (not just inches of mercury like your gauge set), a set of gauges, and a refrigerant scale to get an accurate charge this basic set of tools mentioned above can be cost prohibative especially if you will only use them once.

Not to mention sizing the condenser unit to your residence the word Tons and BTUs are used rather interchangably they both refer to the cooling capacity of the condeser unit for example 4 tons is the same as 48,000 BTUs. Too small a unit and your home will not cool adequately the condensor unit will be running very often and waste energy. Too large and the unit will cycle on and off too often causing wear and tear on the condenser unit.

I'd rather not get into SEER ratings and all the things that can affect them.

The charge they refer to is most likely nitrogen (a dry gass it sometimes is used for leak detection) it is injected into the evaporator to prevent moisture from accumulating inside prior to evacuation which will boil the moisture off anyways. The caps are to be removed right before soldering the tubing to the evaporator ONLY.

If you intend to take on this colossal task and do the hookup yourself get an A/C tech to check over your work and evacuate and charge the system.

This is by no means a definitive list but simply a brief overview.

Very nice, but 10 minutes on Google does not an expert make. What's your RSES license number? Mines 0306000051 - Universal.

I am by no means an expert I just like to answer questions thoroughly. Most of the info was from things I've read in training manuals and exam prep books.

Nowhere did I say that I was an expert or HVAC technician and last time I checked it said member under my name.

I have the tools mentioned above the only hands on experience I have is with automotive A/C (I got section 609 so I could purchase R12 for an old car that I didn't want to retrofit) I still don't have a recovery machine so I sub that out when I'm doing work for myself.

I have yet to go for Type 2 however I am considering it for educational use.

A superheat conditon can only occur in a charged (or undercharged) A/C system it has nothing to do with his question?

It is either due to a restriction or low refrigerant charge. There is insufficent liquid refrigerant in the evaporator therefore the vapor refrigerant continues to absorb heat beyond its saturation point becoming superheated. The tell tale sign is that the inlet pipe to the evap is cold while the outlet is warmer.

brosnt1 said:

All
I purchased a cased ac A coil for my furnace and would like to install it with out installing the condenser. The instructions say that it is pressure charged and the pressure should be released before soldering. I would like to keep the pressure in the A coil until next summer when I hook up the condenser. but I'm worried about heating up the furnace with the A coil pressurized. Could I damage the coil? would I allow contamination into the system if I remove the pressure and leave it open to the atmosphere for a year?
you advise will be greatly appreciated.

Click to expand...

What you are asking right now is not about hooking it up, but rather if the unit would be damaged if heated up to 180F ? before the condenser lines are ran.

The answer depends on how much pressure the unit has been charged to.

Unfortunately I don't have the answer.

FYI: The "A" coil I have uses chilled water... It was soooo much easier to install.

The refrigerant charge is in the Condenser unit. Your A coil is just pressurized with a little nitrogen to keep the humidity and corroding oxygen out.

Install it, leave the plastic plugs in and you'll be fine. The worst thing that happens is the nitrogen heats up and pops a plastic plug, but I doubt that will happen. If it does, pulling a vacuum for a while before charging will get rid of any air and moisture that gets into the coil.

nhmaster said:

Then why, with the exception your ego, would you even attempt to give refrigeration advise?

Click to expand...

Aww my confidence threatens you thats cute at least my ego doesn't get in the way of providing him with detailed advice. My confidence comes from researching before I tackle any job. I had the answers to his questions I answered them. Welcome to the Internet love it or leave it.

I'm sure by the time you read the sentence above you're thinking that's why I hate the Internet any idiot can post their opinion without being responsible for their actions. The burden isn't on them it's on THE PERSON using the advise EVERYONE expert or not can make mistakes. Diyers range from horrible to good just like experts do. You can get the same advice good or bad in the real world and it's YOUR job to filter it.

I can tell someone what E=Mc2 means without being a physicist.

I highly doubt if that question was answered on another forum that a psysics professor would ask the question what qualifies you to answer that?

At least in my answer I didn't throw a bunch of random words out in an attempt to seem cryptic without elaborating.

Not to mention if someone happened across this page via a Goggle search it would save someone else the time of answering the same question.

Please get off your high horse already I don't dispute all of your experience but that's just half the battle for me the other half is how you communicate with others. Experience isn't the only thing that demands respect the other half is kindness towards others and the will to share knowledge with those who know less than you without looking down on them.

Your constant asking for certifications and licences makes me think that you are trying to prove youself to the world. True professionals don't have to justify themselves to anyone. Saying you have them and asking the poster if they have them is good practice for legal reasons but asking for proof speaks volumes.

Well I'm done with this thread and certainly this conversation before it becomes another plumber DIYer tag team match that I simply don't have the energy for.

Last time I checked this was a plumbing and remodel DIY advise forum not a PLUMBERS ONLY advise forum.

Good Luck Brosnt1

Well I'm done with this thread and certainly this conversation before it becomes another plumber DIYer tag team match that I simply don't have the energy for.

Thank you.

nhmaster said:

Do you have a vac pump, a micron gauge, a nitrogen bottle, a decent set of vac&pressure gauges? Do you have any idea what "super heat" is, Do you know how to silver solder or braze? Finally do you have an RSES ticket to handle refrigerant? If the answer to any of the above is no than you need to call a professional.

Click to expand...

nhmaster,
Yes, I have the proper equipment and training, and I do have a univeral license. The reason I ask is because I usually work on environmental chamber and not residential system and was hoping a residential installer has made this kind of installation in the past, and could advise me about the pressure left in the A coil for a heating season, and the possible damage it could cause. That's all I wanted to know.

Mount it, and don't worry,.........it is not charged with refrigerant.
It has a small dry nitrogen charge in it.

Cased coils are rated for the heat coming off a furnace.

brosnt1 said:

nhmaster,
Yes, I have the proper equipment and training, and I do have a univeral license. The reason I ask is because I usually work on environmental chamber and not residential system and was hoping a residential installer has made this kind of installation in the past, and could advise me about the pressure left in the A coil for a heating season, and the possible damage it could cause. That's all I wanted to know.

Click to expand...

So are you going to tie in the suction and liquid line's or just leave the coil in the cabinet? If you leave the coil in the cabinet then just leave the plugs in and maybe put a bit of tape over them just in case. Coils are typically nitrogen filled to keep moisture out and if you can at all maintain this condition all the better. As you know, moisture is a killer in hvac systems.

I will not be hooking up the line until spring. Thanks everyone for the advise

You know darn well that spring will turn into summer, it will be 95% out and your wife will be all over you.

BTW if you loose the directions I'm sure there's someone here that will be glad to Google them for you

I am agree with nhmaster just follow him