What's the best home A/C system these days?

schamp · 07-19-2015, 02:09 PM

Looking for information about home a/c systems. I currently have a geothermal system for past 13 years. Getting tired of replacing water pumps every couple of years. So, has anything come along that would be better. Need two 3 ton systems, and maybe another 2.5 ton.
Thanks for any and all replies.
Schamp

billybek · billybek's Garage

Wonder if the glycol side is under designed for you to be going through pumps? Never heard that complaint about ground source heat pumps before.

All the big players are pretty good these days. Looking for a central system for both the 3 and the 2.5?

Are you looking for heat pump and not just A/C?

schamp · 07-19-2015, 02:19 PM

There is 3000 feet of pipe in the ground on each side of the house. The glycol or weak glycol keeps rusting out the pumps. There are 3 systems and three pumps. I keep three spares.
Getting a little old to contort myself to be able to change the pumps.
Yes, heat pump. Doing both a/c and heat.

Thanks

billybek · billybek's Garage

One of the issues right now is that whoever sells to you is going to want to sell you a R410a system and that can mean a lot of pipe work.
What they are not telling you is that you can still get R22 equipment new and either put R22 in it again (kind of pricey) or switch to one of the R22 drop in refrigerants without having to worry about replacing all the components in the system.
If the system you have is 15+ years old then maybe a total rework should be considered.
If you know a trusted company, get them to come and have a look. Since you are not desperate for replacement (system is still working) wait until low season and maybe get a break on labor.

Cajundaddy · Cajundaddy's Garage

"Rusting the pumps" sounds like a corrosive coolant mixture problem. Most geo systems are pretty dead-nuts reliable if you get the coolant and engineering right.

schamp · 07-19-2015, 03:11 PM

I agree about the mixture problem. The fix is to dig up the pipes and put in some kind of flushing station. Then every five years or so do a complete flush. What gets me is how does the pump rust if there is no air in the system? The only thing that's metal is the pump.
I guess it would be cheaper to put in two flushing stations, new master pump station and take the pump out of each unit. There are some stainless impeller pumps but very pricey.
The units are Florida Heat Pumps.
The kicker is, I have three two ton units for my shop. One of my projects is to hook all three up to a lake loop and cool the shop. They have the same pumps.

Thanks
Schamp

rfuerst911sc · 07-19-2015, 03:54 PM

Look at mini splits. I added one to a two car garage it is amazing. I bought Mitsubishi ( the best ? ) and have no regrets. Quiet, efficient and not too bad on price. Check out EComfort.com

Cajundaddy · Cajundaddy's Garage

Quote:

Originally Posted by schamp

I agree about the mixture problem. The fix is to dig up the pipes and put in some kind of flushing station. Then every five years or so do a complete flush. What gets me is how does the pump rust if there is no air in the system? The only thing that's metal is the pump.
I guess it would be cheaper to put in two flushing stations, new master pump station and take the pump out of each unit. There are some stainless impeller pumps but very pricey.
The units are Florida Heat Pumps.
The kicker is, I have three two ton units for my shop. One of my projects is to hook all three up to a lake loop and cool the shop. They have the same pumps.

Thanks
Schamp

Mineral content (CaCO3 and NaCl) in your coolant solution will cause corrosion just like tap water in automotive coolant. It should be pretty easy to create a valve system to flush out the coolant just like flushing the brakes on your car. A 50/50 glycol-distilled water mix will not promote corrosion in a clean system. Maybe consider an all plastic pump designed to handle corrosive or salt water solutions? I don't know what your pressure and flow rates are but If the plumbing is all plastic it is probably still viable. If it is galvanized, copper, or mixed materials you may never eliminate galvanic corrosion in the system.

If you are truly done with your geo system, the mini-split is a worthwhile consideration. Very efficient and reasonably simple install.

javadog · 07-20-2015, 04:08 AM

Quote:

Originally Posted by billybek

One of the issues right now is that whoever sells to you is going to want to sell you a R410a system and that can mean a lot of pipe work.
What they are not telling you is that you can still get R22 equipment new and either put R22 in it again (kind of pricey) or switch to one of the R22 drop in refrigerants without having to worry about replacing all the components in the system.
If the system you have is 15+ years old then maybe a total rework should be considered.
If you know a trusted company, get them to come and have a look. Since you are not desperate for replacement (system is still working) wait until low season and maybe get a break on labor.

I have a 3 ton Trane that needs to be replaced. It would not be practical to replace the piping and I'm not as big a fan of Trane as I was 20 years ago. Recommendations?

JR

billybek · billybek's Garage

I need to replace an aging high efficiency (Trane) as well. It has gone a bit glitchy on me and looking at the cost to replace vs. the cost to re board and re wire it isn't worth it.
I haven't made a decision yet but I am leaning towards a York two stage variable speed blower.
Any of the big three, York, Trane, Carrier and their spin-off brands will most likely do.

The piping can be an issue if the length of the piping run is long and the system is converted to R 410a. Ususally a flush is done on the piping to eliminate the mineral oil from the system. The Polyol Ester Oil (POE) doesn't play well with the mineral based oil in the existing system.

Usually a new system will have a new evaporator matched to the condensing unit. New coil new condenser. Re utilizing the existing lines is possible but usually will produce some pressure drop due to higher refrigerant velocities through the system. Long runs compound this problem.

Most of the time I recommend to buy what ever product is being sold by a good contractor in the area that you live.

javadog · 07-20-2015, 05:11 AM

I have a long piping run to deal with. The coil is upstairs and about 30 feet laterally from the condensor. The piping is essentally inaccessible, so replacement is not a viable option.

This Trane unit never really cooled all that well. Towards the end of it's life, I was getting only a 9 degree delta between the supply and return air. I eventually quit running it alltogether.

JR

red-beard · red-beard's Garage

Whatever you get, get one with a VFD - Variable Frequency Drive.

cabmandone · cabmandone's Garage

Carrier

I was going to leave it at that but it seems to me you're throwing the baby out with the bathwater. Have a reputable company do a flush of your loop and install a new pump. As maintenance have them install a new one for you every 3 years. Can't be anywhere close to as much as the cost of a complete system install and most certainly not when you look at going with a high SEER rating unit which will require a matched air handler to get the most efficiency.

cabmandone · cabmandone's Garage

Quote:

Originally Posted by javadog

I have a long piping run to deal with. The coil is upstairs and about 30 feet laterally from the condensor. The piping is essentally inaccessible, so replacement is not a viable option.

This Trane unit never really cooled all that well. Towards the end of it's life, I was getting only a 9 degree delta between the supply and return air. I eventually quit running it alltogether.

JR

You should be able to reuse your existing line set.