From Florida Building a more efficient Air conditioner

I live in Florida my sister lives in AZ .
there areas are HOT in the summer no matter if you live in a trailer ( which is a giant metal box )
or a home from 900 square to 4000 it cost a Ton to cool our homes my sons 1200 square foot home can cost 350 $ a month and never gets down to even 80 % .

Back in the 1960 s there was a Frig that used ammonia to cool it was very very efficient a flame the size of a BIC lighter was enough to run it .
Thing is get a leak and your dead .

Now a Air Conditioner main thing it uses to create cold is a compressor at 75 low side and 230 high side . That takes ALOT of energy to get that much presser . Thous your high electric bills .

Recently I discovered Our pigly wiggly sell C02 ice ( Dry Ice ) now dry ic is cold very very cold - 109 F COLD .Hold it in your hand and get frost bite cold .
Thing is it takes MUCH much less energy to run a frig then a air unit reason being a firg only cools a VERY small space . I would say around 50 $ a month max and if you NEVER opened it around 25 $ a month and if you tripled the insulation 10 $ a month .

So cheep very very cheep .
so Build a device that would be full of C02 and cool it turning it to dry ice have a metal radiator attached by pips and a small built in fan to move the air through the pips and radiator .

Now instead of a radiator we have now that gets cool this sucker gets extremely cold using almost NO energy add a way to keep ice from building up on the out side . And you now have the most efficient air unit ever made .

The amount of c02 needed could be very small so even a leak would be no danger repairs would be simple no presser needed .
A Air Conditioner that would cost 10 $ a month to cool Even a metal box trailer .
Places like malls cost would drop by 20,000 $

so there you have it hopefully The right person will see this the idea is worth a ton .
Ps you still need to figer out a cheep way to heat lol BUT heating is cheaper anyway lots of wast heat in most buildings like the dryer in your Landry .

a reply to: midnightstar

So I live in Miami and my current rental is a fairly new town house, about 1,800 sq/ft, with a new ac unit.

I'm not sure what they have done. But the unit is really efficient. It's cold and I pay somewhere around $100 - $150 in electrical. During the day the ac is kept around 75-78 and at night it's down around 73.

Your son may want to invest in a new energy efficient ac unit.

It takes a lot of energy to freeze co2 into a solid. Water sourced heat pumps seem to be the best answer.
www.energy.gov...

originally posted by: midnightstar
... cool it turning it to dry ice ...

- There is the problem.

You have an issue with your AC system. My house, also south florida, is about 3x the SF and I leave doors open all the time. My electric bill was about $275 in the summer, with AC set to 75 degrees, with an old rusted A/C system. My house got that cool even with doors open. I replaced my system and now bills are down to the $175 range for summer. New system costs $100/mo on installment plan, so basically I got a new A/C for free. You should check it out.

It's more than just the ac.
Insulation is often overlooked.

I used to build custom motor coaches and we installed roof air conditioners when most companies installed a split internal unit.

In the heat of Arizona our systems could exchange air easier than the the ones that were sucking hot air off the pavement.

Sometimes it's the simplest things that make the difference.

Wile the unit is older the unit is not the issue my sons home has a very low angle roof of maybe 1.5 as such has NO atic .
just 6 by 2 studs which creates a problem you insulate enough to help and trap the hot air causing the roof to tear up .
Or leave it empty and lose cool to the inside roof being hot .

BUT i degrees building a cooling unit good enough to frezz c02 would cost little money and be very cheep to run ONCE frozen it stays frozen the unit would Not be running 90 % of the time - 109 is colddd .
and again you only NEED a very small one for this to work a pound of c02 would be more then enough .
this would work .
for all you who have 175 bills with the door open ( who you kidding ?? lol ) I had a all wood home wood is a great insulator and my bill with a BRAN new unit could hit 350 ten years agaio .

anyway this would work and be very cheep for a big home 30 $ a month cheep so if someone makes one and its only a few k just keep paying the extra 150 a month if you want .

ps the piggly wiggly sells the dry ice at 299 a bag which looks like alest ten pounds .
Just building a simple box and buying the stuff would cost less then 175 a month lol
more they could not sell the stuff so cheep if it was high cost to frezz it .

a reply to: midnightstar

The sublimation heat of dry ice is 200kJ/kg

Your 10 pound of dry ice would be about 900kJ cooling enrgy. That is not much.

10 pounds dry ice / hour would be about 250 Watt cooling power.

a reply to: midnightstar

You should build one for your son and see how it works out

The ammonia refrigerant is still in use- pretty much all industrial or walk in freezers use ammonia. They don't use it with a flame, though- that's an "Einstein refrigerator" - todays use 3phase compressors.

Dry ice isn't cost effective, though. If you're spending hundreds a month to chill a place there's either something wrong with your AC or the windows are open. Are you using windowshakers or something?

Remember- they're making dry ice with co2 and electricity. Add in the overhead of employment, equipment, transportation, and extra raw materials and there's just no way cooling with dry ice is effective when compared to just using a good AC unit in the first place.
Modern heatpumps are incredible- and in florida you've even got the humidity outside helping you wick heat out of the condenser.

Humm well the one person who looked up the amount of cooling energy in the ice is who I would go by for this idea .
as for making a test BOX and just buying ten pounds of the stuff and seeing just how long it could cool yes ill probly try it out wont cost a 100 $ just to do that with junk laying around .
Thing is ten pounds in just a ice chest last the whole day no problem which is very bad at holding cold for long as it is being opened .

The thing that would matter is it would be a closed system would build up presser on its own as the dry ice went gas .
so the only question is how long would ten pounds last staying cold .
If it was even 3 days the system would cost a 1 $ a day 30 $ a month .
Adding in using just one pound AT A time per day then it could do great .
its not like the ice is in direct contact with the hot air .


But the post moebius made is probably right so more then likly there goes my idea for a better cooling system .
Hey any idea is worth exploring .

a reply to: midnightstar

I do hvac for a living, what your describing wouldn't work. If your looking to save money on power, you need to get a newer energy efficient unit. If budget isn't an issue look into a mini split system, by far the most efficient units available right now.

Insulation is the biggest factor here.
Like maximum insulation in all floors, walls and ceiling plus double glazed windows all round and well sealed doors. The problem then is you're committed to using the heat pump for cooling/heating virtually all the time but at least it will be as efficient as it can be.

Being in Florida, you should have all your duct work in the attic.

You really should have them inspected. I used to flip houses there. Every one I bought had massive duct leaks on supply and return lines.

Most of my neighbors had the same issue. One of them even had the cap on the end of a 12" supply line completely missing, and it was a 500k dollar home.

You can buy a flir thermal camera for your cellphone for like 200 bucks. I have tracked down all kinds of leaks and missing insulation with it, as well aa water leaks, which are a cool temp too.

My last house was a nightmare with ductwork issues.

One big problem with Florida, is the attic temps. Often, they don't use the right products, or don't insulate the ducts, so the duct is heated to 150 degrees and it heats the cool air. Foil tape adhesive fails in the attics and leaks start. The smallest leak in the return line sucks that heat into the unit and it can't keep up.
They are only meant to change temp like 35-40 degrees, so over 100 degrees on the intake is a big problem.

Around the plenum is another common leak point. You should be able to feel it leak there.
Use foil tape on it then slather on duct mastic to repair, but don't get the lowes crap, go to a ac supplier.

I'd pay to have an inspection of the duct work with a flir, if you are not the diy type, then have them check coil for buildup, keep dust off it and change filter monthly and check refridg levels.