Discussion in 'General Discussions' started by eemaggie78, Jun 5, 2013.
Hello. I am new to the GeoExchange forum.
If a 2-stage compressor is teamed up with an ECM blower motor (this is standard for all the manufacturers that I know of), then you actually will get the added benefit of better dehumidification, which is important if you're in the south. This is because you'll get longer run times in the first stage, which uses lower air flow, which in essence "wrings the air" of humidity. And you're right, you'll get better efficiency at part load. As far as 2-stage being better for heating climates, not sure that's true. Take a look at the submittals or IOM's for the unit you are going to purchase. There's a capacity section that will show you the BTU output in heating/cooling and for part load (first stage) and full load (2nd stage) for different EWT's. You'll want to look for the open loop numbers or sometimes referred to as "groundwater" temperatures. The standards are normally 59 degrees cooling and 50 degrees in heating. Of course your local water temps will probably be different, but this is a good place to start.
In South Texas our ground temp is about 71. We have to use more loop than up north to dispose of excess heat. The two speed systems work great, and will control humidity in the Gulf Coast region very nicely.
My experience with a two speed, in NJ where we get too much Florida Gulf weather for my liking, and I strongly recommend a two speed for both cooling heating, we use both in NJ.
In the low speed the efficiency is higher, the noise is almost zero (I'm talking about noise in the house, not in the basement next to the compressor/fan). It pulls lots of humidity out in low speed.
Be sure to get a Scroll (sp?) compressor, maybe even a variable speed. Mine is a two speed and it shuts down and restarts to change speeds. This puts more wear on the compressor than a smooth speed change. Still, my compressor is almost 20 yeas old. Your experience gives me hope I can get a couple more years out of mine.
I am considering just replacing the compressor, not installing a new unit. The unit is all inside (Other than the loop) so no weathering, it looks brand new.
My area is Jacksonville, Fla. and I rarely install a single stage system other than a few code minimum air source systems for rental properties. In the humid south, the longer run times of two stage systems in low stage greatly improves dehumidification and efficiency.
Single stage systems seem to me fine for heating dominated climates where budget is a concern.
Jerry - it'll take a careful, thoughtful selection of the right compressor to retrofit your 20YOA system to garner the expected efficiency improvement. I'm not saying it can't be done or isn't a good idea, but it puts you into R&D mode. Metering devices may need to be changed to accommodate the characteristics of the new compressor. Are you considering swapping refrigerants? 22 is really pricey and likely to go higher.
"engineer"... I'd like to retro a Scroll (sp?) compressor, even if two speed stop to change speeds as is the case now. That is the control board expects to switch the compressor between two speeds, not to manage a variable speed. That said, I know nothing about how the variable speed compressor works (even it only two run speeds), but I assume it is a "smart" compressor and expects a master board to know now to communicate.
It would be nice if Water Furnace offered a retro - they had to come up with a retro on the forced air three speed fan. That was the first failure at 15 or so years and cost over $1,000 because of some extras needed to make it work with my "old" unit. But at least they had a fix, not sure what they offer for compressors. Given I've also had to replace the loop pumps (two pumps - for two speed compressor) a mew compressor would put the unit back to good as new, save relays and electronics.
I'm not up to speed on refrigerant - I believe the original is of the more modern type that has less environmental impact if lost into the atmosphere. I've used the off the shelf recharge for my automobiles and it wasn't particularly expensive. How much more refrigerant does a 3 ton HP need over a car, 4 times as much? If 4 times the total material cost wouldn't be more than $100. Obviously I have to also pay for the installation, not something I'd try myself.... albeit I do understand the HP and how its controls work. I am up to speed enough on that subject that I caught the WF GeoPro (their strongest dealers) in a screw when they replaced the pumps. In fact the pumps didn't need to be replaced is my bet, but I accepted new pumps were at least new pumps, but the installer screwed up the control board and I think intentionally disabled something so the pumps would work, albeit run all the time. Needless to say the dealer came back and made some repairs. If this happened before I hope he fired the tech working on my unit.
In another post I noted I had a circcuit breaker pop a couple of weeks back. I reset and the HP has been working fine since. I suspect it may have been due to a low voltage condition but don't recall teh power company putting out a "brown out" warning. I haven't looked further into this.
I plan to contact another WF dealer (none are real close) to discuss. This will be something best after the peak cooling season, its been hot (nice for the last 3 days though) when he will not be on emergency runs getting air conditioners back up and running. Hope I don't need to make such a call... my wife doesn't do well with heat and humidity.
I get that. I have seen more divorces over thermostats than checkbooks.
I cannot see that a multi stage HP has not an advantage in pretty much any scenario. If the loads are apart, like heating or cooling dominated climate, you are correctly sized for the both scenarios. But even with a balanced climate, chances are that the heatpump runs 85-90% in first stage. Longer runtime, less cycling, better dehumidification in cooling mode no matter what the cooling load is, usually combined with an ECM blower, much better efficiency, all things that make geo systems shine.
2 stage is an advantage anywhere as is truely variable, the question of whether it's an economic advantage depends on cost/kwh. In my AO operating cost between 1 and 2 stage units may be less than $50/yr.
I also think the added dehumidification argument has far less merit than we give it credit for. Yes it runs longer but it moves less CFM.
What I like best about 2 stage is in open loop applications (which I presume to be the case here). I have seen 2 stage equipment go through 200Kgal less in a year of operation.
I would simply prefer a quieter system for 85-90% of the run time. But you got a point, it depends on how much of budget you have. So far I had none of my customers requesting a single stage unit, and I never put one in (forced air).
Thank you for the replies everyone.
Ahh, you bought a heat pump from someone else and now wish a local pro to install it for you? Good Luck.
Most of us aren't in the business of helping consumers support out of town distributors. Even in my DIY sales I won't sell to anyone that I can't serve with boots on the ground.
We bought a geothermal heat pump to replace an existing through a local 'pro'. We are currently having difficulties with the installer. We have two old FHP geothermal heat pumps that have failed. Our upstairs unit failed first and this is the one the 'pro' is supposed to be replacing. Our downstairs unit gave us its last bit of life over a week ago. We have not purchased a new one to replace it yet.
We placed the order with this 'pro' on 6/28. On 7/22, I was told the order would ship 7/31. Documentation shows it shipped 7/29. This professional actually had it shipped to a local wareshouse distributor, ACES A/C Supply, Inc. in Houston. Since I haven't installed an HVAC in 26+ years, I have no idea if that is standard operating procedure for a HVAC service provider.
The unit was delivered before 8/2 and yet this professional could not make the time to schedule installing it for me. On 8/6, I finally got them to agree to Fri 8/9. But then it appears as though even that date has been inconvenient for this company. The technician they sent to install it told us he was told of the job via a text message the night before. He came totally unprepared.
This technician ripped out the old one, then proceeded to install the new one without the pad, water connected backwards and, when turned on, multiple leaks. He came back late Sat, ripped out the piping and pulled the new one to put the pad underneath, then left and did not come back.
As of today, the installation is incomplete.
I choose not to share the name of this professional at this time, not without giving him an opportunity to provide us the service he committed to provide. But it makes us nervous to use him for the 2nd unit. And currently, in Houston, we are without either unit running. No HVAC. And that is an unacceptable condition for this professional to have left us in. The only phone call we received from them was Friday afternoon when we were informed the bill with the remainder of the balance was e-mailed to us for final payment.
You sure made an assumption and your response was not nice. I thought this was a professional, respectable forum to participate in. One that shared information.
I deal with contracts and installations at a petrochemical facility every day. I will show you common courtesy and respect, but I also expect to be shown it back. And Mr. Hardin, I do have my boots on the ground. I follow a tenant to always involve people with expertise and first hand knowledge in decisions, improvements, and changes that affect equipment. The company we selected told us he did residential geothermal heat pump installation, displays such on his website, and participates in this forum. That is one reason why we selected him.
Now I sincerely hope there is someone out there who can actually give me a good recommendation for someone they used to install a residential geothermal heat pump in or around the Houston area.
the angle many of us come from is exactly what you are experiencing, namely that the satisfaction of the customer depends on the integrity and quality of the installer. The brand of heatpump is in most cases irrelevant, unless you have some special design or use.
I also sensed that some of your dissatisfaction comes from the "delay" in the installation. It is normal that units get shipped to the distributer. Please also understand that sometimes a company cannot drop everything else to accommodate you. We are about 6-8 weeks out, and in about a month I will have to turn people away to get their system installed before the end of the year. What you are describing can happen when companies squeeze in jobs and end up not being able to come through.
So last week he agreed to send someone out within a couple days, the install was not well prepared, the installer did not seem very skilled? He came back on a Saturday, did not get it done, so it is Monday and you are hot in Houston, looking for another installer.
I tell you right now, it will be very tough to find a skilled company, which will all be very busy right now, to step in, drop everything else, meaning abandon their customers for you, and take over responsibility for that unit and that install. Not much to gain, much to loose.
Try to find a solution with your current installer, just a well meant advise.
I guess I'm still not stating this correctly. The current installer is going to finish this job. I am sure he will do a quality job by the time he has finished and started up the unit.
I did make assumptions based on the information you offered. We often have to do that as most people only give us part of the information or convey their thoughts poorly.
Perhaps you are not expressing your actual situation well enough to be understood. I think it's fair to say that my comments were not unkind or unprofessional unless I was already privy to this comment: "We bought a geothermal heat pump to replace an existing through a local 'pro'" and this "The current installer is going to finish this job. I am sure he will do a quality job by the time he has finished and started up the unit." But of course you hadn't shared that yet and the latter comment doesn't seem to fit with previous ones (and my crystall ball has been acting up).
I can also tell you that I do not schedule installations until I know the unit arrived at my local supply house (though I seldom have to wait for one to come from OK), then I schedule delivery to the job and measure in situ sheet metal transitions, after which we schedule installation. Certainly there are days in between these events from time to time. Frankly I'd be more worried if your contractor wasn't busy.
That your contractor and his agent represented poorly after that is unfortunate and certainly not reassuring or professional based on your description, but I also sense that expectations and communication are part of the problem here. After all I haven't taken any of your money and I've managed to raise your ire as well.
Separate names with a comma.