There is no Yes or No to this question.
Chlorine & Copper
You will have to keep your chlorine and acidity levels in constant harmony, otherwise the acidity will corrode and pit your copper tubing. Using aluminum would be exponentially worse. It the cooler your pool water gets, the worse effects it would also have on the copper. You can find good information from the EPA.
BTU's
A BTU is a British Thermal Unit. It takes one BTU to increase the temperature of one pound of water by one degree Farenheit. The average swimming pool is 20' x 30' x 5'. That would mean that the average swimming pool is about 22,500 gallons of water. Since one gallon of water weighs 8.34 lbs., the water in an average sized pool would weigh 187,650.
That means it would take 187,650 BTU's to increase that pool temperature by one degree. Since you would only have about 10% of that amount of BTU's required - it is very likely that the pool would simply absorb and disperse the heat transferred from your residence and never actually raise the temperature of the pool. Gullberg & Jansson has some great information on their website about heating pools.
Refrigerant and Line Set
In general it would take about 0.6 oz of refrigerant for each foot of copper tubing above 15'. Different manufacturers have different specifications of course. Considering it is a window unit, it would already have less refrigerant than say, a mini split unit.
The average 1.5 ton, or 18,000 BTU, mini split unit take about 3-4 lbs. of refrigerant and usually have about 15' of line set available 'in the box.' Depending on how long your copper tubing would be, you could be seeing so much heat loss just within the copper tubing itself, it would never "make it" to the pool. Plus, all of the possible extra refrigerant would be so hard on a compressor that small, compressor failure would always be right around the corner. Some good information can be found at ACHR News.
Legal Activity
In order to 'work' with Refrigerant, in fact, even buy (most) of it, you have to be EPA Section 608 Certified. There are 4 types of certification. There is Type I, Type II, Type III, and Universal. There is also EPA Section 609, but that is for motor vehicles. Without certification, you run the risk of EPA prosecution. And before you think that you will never get caught, there is a reward for turning people in. Information can be found at the EPA website.
Tools You Need
- Recovery Machine
- Recovery Tank
- Vacuum Pump
- Manifold Gauges
- Low-Loss Fittings
- MAPP or Oxy/Acetylene Torch Kit
- Pipe Cutter
- Pipe Reamer
- Sand Paper/Emery Cloth
- Silver or Silver Phosphate Brazing Rods
- General Mechanics Tools
- Possible a Bucket of Ice and/or Bucket of Warm Water
- Various Other Tools Depending on the Task at Hand
As you can see, there is a lot of specific tools and machines that you need to perform the job, not only legally, but safely. They are also very expensive to the average person. It is not uncommon for a vacuum pump to cost between $150 - $500. You can double and triple that cost for a Recovery Machine. There is a reason that most technicians work for a company that provides all of the tools required. It is hard to start off in the industry self-employed when you require certifications and tools that all cost money.
Conclusion
I would find a local HVAC/R Technician and run the idea across him. Ask him to come out and see what the job would entail. Ask him for advice. Ask him for a material cost and/or a list of what it would take to get the job done. Remember, this is only estimate stuff - because he may just tell you it isn't worth it, isn't possible with the equipment provided, or would be much more hassle than the intended benefit.
You could hire me to do it! But that would cost you a plane ticket, a case of beer, and a good home cooked meal before I even consider it.
About Myself
I am a...
- Section 608 Universal HVAC Technician
- Section 609 MVAC Technician
- Certified Commercial Mold Inspector
- Certified Indoor Air Quality Technician
- Certified Green HVAC/R Technician
- CO2 Refrigerant Safe Handling Certified
- R-410A Refrigerant Safe Handling Certified
- Certified Home Inspector
- Member of American Society of Heating, Refrigeration and Air
Conditioning Engineers
- Associate of Institute of Refrigeration
- Member of International Association of Certified Home Inspectors
- Member of International Association of Certified Indoor Air
Consultants
Best Answer
Air conditioning systems must be thought of as just that, systems. If you get a 4 ton outdoor unit you must have a coil capable of 4 tons as well, often times I will upsize the coil slightly to get better air flow and a higher efficiency. Air flow is also a huge factor in whether or not you will actually get 4 tons of cooling in your home. If you have 3 tons of air flow and 4 tons of cooling you are effectively paying for 4 tons of cooling but only receiving 3 tons. The indoor coil is likely old and inefficient and will not match up well with the new outdoor unit in terms of efficiency. If you upsize the outdoor unit you likely will not have enough air flow to handle it. Your ducts are probably too small and your furnace blower may be too small. If you really can only replace the outdoor unit due to cost here are some suggestions. Make sure you have enough air flow. If you don’t, upsizing the outdoor unit will not help and just cost more money. Don’t pay any extra for a higher efficiency unit since you will not realize any of that extra efficiency hooked up to your old equipment. The higher efficiencies are only realized with complete systems. The old mineral oil will need to be flushed from the system since the new POE oil is not compatible. The metering device at the indoor coil will need to be replaced since it will not be compatible with the new outdoor unit. If you have capillary tubes as your metering device you will likely need a new indoor coil since it would be too costly to change those. Verify that your existing refrigerant lines are the proper size, many older systems had really small lines that don’t work well with today’s air conditioners. Getting quotes over the phone is never a good idea since there are so many factors involved. I could tell you a cheap price to get my foot in the door just to bump it up when I get there. That will likely exclude many honest companies that realize a price on the phone cannot be done. A cheap quote to just replace the condenser without checking the rest of the system for compatibility may be doing you a disservice. I would not automatically dismiss a higher bid as a scam but carefully compare all the details. And see what you are getting for your money.