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Make Smoke, Boil Water!
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I just finished having our 24-year-old heat pump system changed out, and got to thinking that maybe all the research that went into the new system, plus a description of the various kinds of systems and their efficiencies, might make a good article for the Tech Forum.

Background:
We'd had a succession of service calls on the old unit, and in the middle of the last one of those, it went BANG and quit completely. :eek:mg:

We got lucky. We were both out of the way when it failed catastrophically. But I turned to the service guy and said, "I think this might warrant a discount on the call." We were also lucky that this was an electrical failure only and that none of the old ozone-depleting refrigerant was lost.

We have a pellet stove, and used that full-time to stay warm while I did the research and called various dealers for bids.

It took about three weeks of research, bids, and bid modifications before we selected a system type, and then a dealer to install it.

A look into the research:
Essentially, there are three types of systems: what I'll call a 'base' system, (our old one was this type) which works like a furnace: stat calls for heat, it turns on. Stat hits set point, it turns off.
There is a second type of system, what I'll call a 'multi-level' system, where the stat calls for SOME heat, it turns on at a lower level, then like the 'base' system, the stat hits set point, and it turns off.
The third type of system is what I'll call a 'variable' system, where the system periodically flows air to keep the house more comfortable and with no cold spots. Heat is added in small increments, only when needed. The efficiency gains come from the intelligent electronic controls, and the inverter-type motor control systems.

This article might be fairly long, but I'll insert links to the different system types, and I have some photos of the changeout process. It's not a complete documentation because the components are heavy and expensive; and I needed to stay out of the way. But the idea is to take a lot of the mystery out of these newer, energy-efficient systems.

This seems like it might be a valuable article; if so, let me know if you agree and I'll go for it. I intend to build it in installments so anyone here who is an HVAC expert can help keep me on track. Then I'll bring all the components into a 'master' article which can then be posted in the Tech Exchange; this ould be unless the Group opinion here is to keep it in a series of shorter articles.

Let me know what you think. :thanku:

Thanks!
 

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i would be very interested in seeing what you have learned.
 

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would like to add. im a goodman dealer. Have been the hvac biz for 14 years. there is so many types of systems out there. so many different combos. and the cost can go from a few hundred bucks to 10s of thousands. if any one has any questions i could do my best to help or answer any question. a few things as a home owner can do to help keep the system up to par. is CHANGE YOUR FILTER! THE MOST IMPORTANT THING A HOMER OWNER CAN DO. now that side. wash out the condensor unit out side. and keep all that grass and shurbs away from it.
 

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Helstar, maybe you could throw in some knowledge about variable speed heat pumps,,,

I am DYING to spend a bundle on such a system,,, it seems like the best answer,, :dunno:

Variable speed has been the answer to industries such as steel manufacture and material handling since the 1950's,,

It should be the answer to the comfort question,,, :fing32:

I just do not know if the manufacturers have done enough development,,, yet,,,
 

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Make Smoke, Boil Water!
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Discussion Starter #7
I can give you some observations about where we are now, with the system being four months old.

It's QUIET!! I can't believe how quiet the outdoor unit is when running. And other than at initial install and calibration, I have not heard it running at full speed. We had a couple of 80° days last week and I was sitting outside on the back deck, reading. At one point I got up and went around the side of the house because it sounded like a car was idling in my driveway. No, it was the heat pump.

Economy: this is the one everybody wants to know, but is different for everybody. For me, I was heating the house with my pellet stove, and the feed store where I buy pellets has been raising the prices regularly. I figured that the heat pump would be the way to heat the house, if only it could do it economically. I checked my utility bill and there was no difference between February and March's bills this year versus last year. Both years were about the same for heating days. Meanwhile, the pellet stove hasn't been started since the day the new heat pump went into operation.

I was paying an average of $150 per month for pellets, so this is a clear savings.

Speaking of payback time: This is something that's different for everyone, and you have to do your own calculation. For us, the payback time of a 2-stage system was only three months longer than the payback time of the infinitely variable system. We intend to be living in this house for many years more, so that's the way we went.


And the article is up; click HERE.

I gave some links to things that helped me. See if this answers most of your questions.
 

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You mentioned the $8K cost,,, did you;
1) include manufacturers discount?
2) run into any power company discounts?
3) notice any other discounts we should consider?

My system is old, the air handler was installed in 1979, the outside unit failed and was replaced a few years later.
It still works,,, but,,,, efficiency gotta be :sidelaugh
I really do not want to go through another heating season with the old system,
so I have some time,,,

I have read the off season (like the fall) can produce better discounts.

I like the system you purchased,,, :fing32:

Years ago I read the variable speed units do a better job of controlling summer humidity,
maybe you can give us some feedback on what you notice,,, :dunno:

Thanks for the great article!! :drunkie:
 

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I would really like to read that article.
Last month I bought a Pioneer 12K btu Mini-split Ductless Heat Pump with inverter for my 500 sq. ft. cabin in the Ky mountains.
I paid $780 for it, delivered.
Though I haven't put it in yet, it seems to be a very simple installation.
http://www.highseer.com/ductless-mini-split-heat-pump-wye012gl5.html
 

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Make Smoke, Boil Water!
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Discussion Starter #10
You mentioned the $8K cost,,, did you;
1) include manufacturers discount?
Yes, mfr's discount was $500 at the time I put the system in; I squeezed them for an additional $300 to match another company's quote. But we installed the system that ran to about 1.5 times the 2-stage system - the payback was only a couple months more, and we intend to stay in this house for many years.
2) run into any power company discounts?
We're getting 3% money (IIRC) and a long term through our power company; they would have arranged an additional ongoing power discount if I wanted a loop in the water heater... but as the water heater is 30' further away, the install costs far exceeded any payback.
3) notice any other discounts we should consider?
I got an additional $150 knocked off because I had the "Complete Comfort" system installed; this adds the 'hospital-quality air' filtration unit. You only have to change that filter and the UV bulbs once a year; cost to replace them is about $125. I have REALLY noticed a reduction in my allergy reactions with this system running.
I have read the off season (like the fall) can produce better discounts.
Yes, you're correct. But I had to have the system installed right away because the pellet stove being the primary heat source was a difficult-to-manage thing, turning into a total PITA and taking too much of my time to keep us warm from day to day. Plus the output of that stove wasn't sized to heat the house on a really, really cold day.
Years ago I read the variable speed units do a better job of controlling summer humidity, maybe you can give us some feedback on what you notice,,,
So far, the humidity reduction is less. Quite a bit less. And empirically, it seems to make sense: the indoor coils aren't being run as cold (because the system runs at a lower output), so they're not extracting as much heat and therefore as much humidity as a single-stage system. If you live in a really humid climate, there's an add-on dehumidifier that (I think) was going for an additional thousand dollars, installed. It hangs right on the side of the unit, uses the same power feed and control systems, and the same drain. So next to no impact physically.

Thanks for the great article!!
You're entirely welcome, glad you enjoyed it.:trink39:
 

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Steam, just a couple thoughts. A ductless system is the most 'un-custom' system you can buy. You poke a hole in the wall, stuff the lines & wiring through, hang the air handler/blowe/coil thing on the wall, plop the outdoor unit on a base, and that's about it.
Your sheet metal guy likely spent an hour forming the adapter from your old ductwork to the output side of the new air handler. That is custom. The original ductwork was all custom, built while inside your home.
Was there a reason to toss the old concrete base you had poured years ago? I would have used that over one of the new 'portable' bases now installed. Was the new ODU too large to fit comfortably? As long as its 'feet' were on concrete, it should not have mattered if it overhung the edge of the base.
Most times, when you release the new 410a or "Puron" into a system, you have the bottle inverted. It should not be fed 'gas' from an upright container as depicted in your article. Were they done, and just getting ready to disconnect? (I hope).
I have had 3 systems. A Trane, a Goodman, and now a Ruud. The Trane died at about the 4-5 year mark(about a week after we moved in). Compressor locked up. The Goodman that replaced it lasted about 17 years, 1992-2009. Compressor locked up on it too. It also had an evaporator coil replacement, under warranty, but parts only.
The Ruud has been in service from Feb 2009 until current. It too has had the evaporator coil replaced. Twice.
I decided on the KISS principle. Multi-speed fans and two-stage heating/cooling were going to be multiple more pieces, and much more opportunity for things to break.
I had had such bad luck(IMO) with piston compressors that I decided I needed a scroll type no matter what. Many models were cut from consideration by that one factor. If you check now, the majority of compressors are scroll-type. I hope it was a good decision. I found a local installer and sourced the unit from a distant supplier, which worked okay, but I'd be more careful of what I ordered in the future.
We had no plans to move, but I did not want complexity for marginal improvements. I went from an 8 to a 10 to a 14 SEER as time went on. The HVAC, the 'heat pump' water heater, the 'energy efficient' refrigerator have seemingly had no effect on electricity consumption and the electric bill. Seems I am just treading water in that area.
FWIW, the 'nothing stops a Trane' is a nice motto, but I believe they are now using components that are of the same 'grade' as all the other brands. Dave's products are good, as are most of the name brands. You might take a close look at the Goodman/Janitrol/(mumble) line as they have improved significantly in their product design and quality. They are on a par with most of the other name brands.
Have you checked your energy use to know if the predicted payback/break even is going to calculate out as expected? My experience with 'energy saving' equipment is that the numbers don't deliver. OTOH, my brother replaced two huge water-heater tanks with a more efficient 'downdraft' type, and his use of propane has been actually almost cut in half. It truly will pay for itself in about two years, and the rest will be pure savings. He has a water heater, pumps, and a forced air system that blows over a radiator to warm the air. The heater tracks its cycles, and it is truly efficient.
tom
 

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Make Smoke, Boil Water!
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Discussion Starter #12
Was there a reason to toss the old concrete base you had poured years ago? I would have used that over one of the new 'portable' bases now installed. Was the new ODU too large to fit comfortably? As long as its 'feet' were on concrete, it should not have mattered if it overhung the edge of the base.
You're very observant. The new unit has a bigger footprint than the old one (by about 8-10 inches across), so the old square base had to go.

Most times, when you release the new 410a or "Puron" into a system, you have the bottle inverted. It should not be fed 'gas' from an upright container as depicted in your article. Were they done, and just getting ready to disconnect? (I hope).
Yes, the guy had shut the valve and had stepped away for something shich gave me the chance to grab the snapshot. I was initially puzzled by the container being inverted, but he told me that's the way it's done!

I have had 3 systems. A Trane, a Goodman, and now a Ruud. The Trane died at about the 4-5 year mark(about a week after we moved in). Compressor locked up. The Goodman that replaced it lasted about 17 years, 1992-2009. Compressor locked up on it too. It also had an evaporator coil replacement, under warranty, but parts only.
The Ruud has been in service from Feb 2009 until current. It too has had the evaporator coil replaced. Twice.
The system we replaced was a Trane, from 1990. We tended to not use it a lot because of the cost of running it. It was cheaper to buy, maintain, and run a pellet stove in the winter and fans in the summer to meet our heating/cooling needs.

I decided on the KISS principle. Multi-speed fans and two-stage heating/cooling were going to be multiple more pieces, and much more opportunity for things to break.
I work for a manufacturer that supplies the component parts to these OEMs. I've seen the new systems from the inside, and so have good confidence in the design and execution. Although the control systems are more complicated, there are actually fewer overall total parts in the new systems. I came to rule out the two-stage systems because of a couple factors: the compressors weren't as robust as the infinitely-variable systems (warranty period on the ones I was looking at was about half), and the payback on the infinitely-variable system was within a couple months - and we intend to stay in this house at least that long.

I had had such bad luck(IMO) with piston compressors that I decided I needed a scroll type no matter what. Many models were cut from consideration by that one factor. If you check now, the majority of compressors are scroll-type. I hope it was a good decision.
I actually found that in the cheaper single-stage systems, they're still using piston compressors. I knew that I wanted a scroll compressor, since they're not subject to catastrophic failure if they happen to get a shot of liquid; the units used in the high-end systems are actually designed to handle this on a regular basis. In our house before this one, I accidentally killed our compressor when I tried to cool the house too far. The system design did not prevent any casual user from doing this, something I was never warned about, and found out the hard way. Irritating.

You might take a close look at the Goodman/Janitrol/(mumble) line as they have improved significantly in their product design and quality. They are on a par with most of the other name brands.
I did quite a bit of calling around, to the outfits that are certified by our utility (since the loan was coming through them) and got no callback from the Goodman dealer after three calls. Means for disqualification.

Have you checked your energy use to know if the predicted payback/break even is going to calculate out as expected?
I have not quite two years' experience with the system now; although our winter last year was mild, but the summer before that one was a real scorcher. The numbers are actually better than I'd figured initially (I'd put in a small fudge factor, just in case). This new system heats AND cools the house for less money over a full year period than it previously cost us just to heat the house in the winter with the pellet stove and put fans in the windows during the summer. The sample is a little skewed because of the mild winter last year, but the year before that, it was colder/longer than average. I also am considering that one scorcher of a summer, and I'm calling it good and a bit better than good at this point.

There is also an additional factor: My wife had an injury resulting in back surgery, and her mobility is compromised. So she now requires a several degrees warmer/cooler house than before. Although this ups the energy use, the total yearly cost still moves the needle firmly over to the plus side for me.

Hope this makes sense.
 

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Chiming in on the VFD air handlers. I have had two. The first one toasted on the warmest day of the summer 118 f. (phoenix) supplier had failed to notify me of the recall so I got a new motor assembly and board. Still a bear for those of us who do not do this every day. The other is working fine, new 2 years ago. This one the evap pump runs every time the unit cycles, which is about 1.3 quarts. I still run a whole house de-humifier and it pulls another gallon + a day out of the house
I am using the stock ramp up and down cycle from the manufacture. Humidity is a big deal for me as I am allergic to stuff that grows over 40%. If your not that sensitive then a straight fan which is about $400 less would be the ticket. There are differences in the motors so do your home work and identify which motor will be best for you. Some of the motors require a lot less energy than others.

Every manufacture builds to a price point now days. Be sure your comparing apples not oranges.
 
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