Got to play with a Nordyne IQ Drive system this evening...

[Shophound]

Wow. I'm impressed. Somehow at the school where I've been going at night to get my associates degree, they got a loaner demonstrator for the students to see of the Nordyne IQ Drive split system. Everything on this system is variable; the compressor, the condenser fan motor, and the indoor blower motor. It is also equipped with an electronic expansion valve, or EEV.

I asked the instructor if we could start it up and hear it run. He tried to get it to fire up but was unsuccessful, so I asked if I could try. He gave me the go ahead and I thumbed around with the thermostat (which is far more than just a thermostat...this thing can give the tech readouts of pressures, superheat, subcooling, motor amps, etc. There is even a separate module that seems designed for connecting up a laptop to) until I got the thing to start.

At first, the condenser fan began to turn. I then realized the compressor was also running, but it wasn't making the traditional buzzing sound so common to hermetic pots running on 60 cycle AC power. I reached down and felt the suction line and it was quite cool already. About this time the indoor blower (the two units were next to each other so we could see all of it operating at the same time) began to ramp up. It also was whisper quiet.

After it ran awhile it bumped up to a higher running speed, as I had set the thermostat to a ridiculously low setpoint to get the system to start. Even at that higher running level, none of us had to raise our voices to talk. If this thing sat outside my bedroom window, like my current condenser does, I would not even hear it run.

The instructor read out of the IQ Drive manual concerning the control strategy for this system. It basically runs almost all the time when conditions call for it...which would likely cause most people to think, "That'll send my electric bill through the roof!" Actually it won't, because this system can do the very thing every single residential system should be able to do; i.e. match capacity to the load on the house precisely. It's never oversized, it's never undersized. The compressor on this system has the ability to run at 18% over nominal capacity due to the inverter driven motor for the compressor.

I could only imagine the comfort level this system could give. Installed into a house with a very good duct system, I would expect very even air temperatures throughout the home as the system could circulate air continuously without spinning the meter off the wall at the same time.

Right now the price point quoted to us from our instructor's information was way off my budget radar. Nevertheless I can't help but state I believe I've seen the wave of the future concerning residential split system HVAC. The price point will no doubt come down over time as this technology matures and more competitors enter the market. What will drive it is continually rising energy costs. As population growth continues straining energy sources, prices will only go up. It may be a few years, but the payback on systems like these will become more attractive as their installed price drops concurrently with energy price hikes.

These systems will likely also have less of a "hack" factor as they are expensive to buy, and the installation procedures must be followed carefully to avoid a world of headaches for the installer. I don't see it being the death knell for hacks, as the cheaper technology will be around for quite some time to come. But comparisons were being made tonight between this IQ system and the modern car service technician, who is completely hamstrung unless he has a way to electronically interface with the vehicle.

Overall, impressive. Only the price was not. For now. :cool:

[gan]

Yeah thats a nice system went to the training seminar for it last year, was one of a couple students invited to go it. The system is super quiet the unit ran while he taught a section of the class. If I remember correctly its all DC voltage and it runs all the time at lower speeds and ramps up as needed.

[mchild]

shophound,

Thanks for the report. Any word on the timing of the HP version?

[Shophound]

shophound,

Thanks for the report. Any word on the timing of the HP version?

I haven't heard anything yet, but I'll keep an ear to the ground. I also thought I heard that a five ton a/c should be out soon, since currently the capacity is limited to four tons. Even at that, if it's true the compressor can deliver 18% over nominal capacity due to its variable speed abilities, you could tack on about 8600 BTUH to a 4 ton compressor of this variety. That would bring it closer to five tons.

[mchild]

shophound,

Yes, I have heard the the 4T unit has a max capacity of 54K BTU.

The issue I want to see is how effective it will be at the low end of the capacity in dealing with humidity. Seems like an evaporator that can handle 54K is going to be huge when the call is for only 15K and thus the coil would not be much cooler than the return air and there would not be a lot of moisture extraction.

[wconell]

Trane had a complete VS system like that in the 80's-90's. It was a nice system and I had 6 of them out there. There were issues with some of them and the price of the equipment at that time scared most people away. I replaced one that was 12 years old and it never skipped a beat in all that time. If you required a 3-3.5 ton system, a 4 ton was used.

[Shophound]

shophound,

Yes, I have heard the the 4T unit has a max capacity of 54K BTU.

The issue I want to see is how effective it will be at the low end of the capacity in dealing with humidity. Seems like an evaporator that can handle 54K is going to be huge when the call is for only 15K and thus the coil would not be much cooler than the return air and there would not be a lot of moisture extraction.

The indoor blower is also variable. The coil is metered by an electronic expansion valve. It is going to maintain a superheat on that coil corresponding to the load on it. For dehumidifying, a reduced blower speed is what would be desired as it is, since doing so raises the latent heat removal capacity at a time when sensible heat capacity is less important. The compressor is delivering the proper amount of refrigerant to the EEV, the condenser fan is running to hold a specific subcooling (vs. delivering too much or not enough), the EEV is holding a specific superheat, the indoor blower is running under a dehumidification strategy. All of it working together to hold the evaporator in the near ideal state...where complete vaporization occurs near the end of the coil.

I think the key to all this is the variable speed compressor. The rest of the refrigeration loop no longer has a constant speed compressor to deal with, nor constant speed condenser fan motors and constant speed indoor blower motors. From my estimation, since this system has the ability to self monitor about everything happening in the system, the EEV always has a set pressure differential (delta P) across it. With conventional systems using a TXV (or far worse a fixed restrictor), the delta P over the valve can vary, since the compressor can't vary speed, nor can the condenser fan. As many may already know, a delta P over a metering device is important. Too much and the coil floods, not enough and the coil starves. The TXV can do a good job mitigating delta P swings, the fixed restrictor far less so. I can see an EEV attached to a system like this as being a very precise metering instrument.

I'm still blown away by how quiet this thing ran. It did not sound like a conventional condenser at all. It made a slight high pitched sound from the inverter pulses into the motors, but completely missing was any 60 cycle hum anywhere in the system. There were only two uniquely shaped blades on the condenser fan, which when running at higher speed sounded sort of like the old Rheem two blade condenser fans. Just not as loud.

[jkish]

shophound,

Thanks for the report. Any word on the timing of the HP version?

I was told next summer by one of the product managers.

[jdb52]

Shophound,
I hope I don't run afoul of pricing rules, but I don't even think we have dealers for such equipment in my area and you can't find pricing on the internet. Is such equipment 2X, 3x, etc., the price of comparable current systems? I'm just curious. Also, how long do you think it will be before this kind of equipment becomes standard and affordable to the middle class; 10-15 years? Thanks

[tpa-fl]

Your experiences with it sound much like Mitsubishi's inverter-based units. I wish Mitsu would ship their baby fan-coils over here. I'd love to use their systems as central air replacements rather than having to use the current, antiquated technology central units made by the US manufacturers.

[Shophound]

Shophound,
I hope I don't run afoul of pricing rules, but I don't even think we have dealers for such equipment in my area and you can't find pricing on the internet. Is such equipment 2X, 3x, etc., the price of comparable current systems? I'm just curious. Also, how long do you think it will be before this kind of equipment becomes standard and affordable to the middle class; 10-15 years? Thanks

As for pricing, let's just say I was quoted about what I paid for a Nissan King Cab compact pickup truck, two wheel drive, 4 cylinder, auto, a/c, am/fm stereo, cloth seats...brand new in the model year 1987. :D

Economics will completely drive demand and pricing for this technology. I personally see many homeowners not wanting to sacrifice comfort as utility rates continue climbing. It shouldn't have to come down to a choice of turning the a/c off or way up at the worst time of day just so the power bill won't put you in the poor house. For those of us, like me, who live in hot climates, this technology will become more attractive as price points drop. Price point drops are driven by demand and competition. Watch what drives these two aspects for HVAC...utility rates and manufacturers competing for your dollar...that will get all of us closer to seeing this thing more widely installed and used.

If government got involved with tax breaks for this type of equipment, the process would be accelerated. Same if utilities also begin offering rebates, as some already do. Many utilities are at a point where a rebate program for energy efficienct equipment is more cost effective than building new generating plants to meet demand for aging energy pigs. Austin Energy has one of the most generous rebate programs in the state of Texas, and actively promotes it. It is also a municipal utility vs. private/Wall Street so their mindset is a bit different. However, I have heard of other utilites in the past offering similar rebate programs.

[jdb52]

Thanks Shophound,

I get it on the price. Being just west of you here in Texas, when I think about building an energy efficient house (radiant barrier, foam (ICF), etc.) and then combining that with this kind of technology, it's amazing to consider the possibilities for reduced energy consumption. I don't think that either the government or most of our utilities have given the rebate or tax credit issues enough attention. The present credits (government) are modest. One essential component of our energy problem is conservation and we still haven't really gotten serious about that. I guess we will do it the hard way, by letting costs go thru the roof to make us all conserve and also make new technologies cost effective. At least, we can see some help on the horizon with this new technology. It sounds great.

jdb

[barty]

Inverter a/c outside the US are as cheap as chips.

So depending upon what you're actually paying (I don't know the price of a Nissan anything) I suspect that the manufacturers are trying it on!!

Cheers

Richard

[chillbilly]

Ready or not, it's coming.
Varying degrees of control mean the highest efficiencies and comfort levels.
The extra control provided by variable speed everywhere in addition to precise metering is really cool.
I was just reading a study that showed how effeciencies increased when just one variable speed compressor was added to a normal TXV and I was amazed at the results.
I say bring it on. The Infinity lines prices haven't gotten any lower.
Hopefully the prices will get better.
Cool thread.

[Shophound]

Thanks Shophound,

I get it on the price. Being just west of you here in Texas, when I think about building an energy efficient house (radiant barrier, foam (ICF), etc.) and then combining that with this kind of technology, it's amazing to consider the possibilities for reduced energy consumption. I don't think that either the government or most of our utilities have given the rebate or tax credit issues enough attention. The present credits (government) are modest. One essential component of our energy problem is conservation and we still haven't really gotten serious about that. I guess we will do it the hard way, by letting costs go thru the roof to make us all conserve and also make new technologies cost effective. At least, we can see some help on the horizon with this new technology. It sounds great.

jdb

You're my Abilene neighbor, if I remember correctly. I also turn over thoughts all the time regarding constructing an energy efficient, comfortable house. My brother down in Austin is looking at a construction method called "Rastra" for his proposed house. I haven't really looked into it yet but the architect was with us on Saturday and quoted some impressive R values. I personally have looked at a product locally called "Thermasave", which is a structural insulated panel (SIP) system. It also touts impressive R values, and to me does not look all that difficult to erect.

My own thoughts are to make the best of passive solutions to interior comfort management and then bring in the mechanical to temper extremes in temperature and humidity. For most conventional residential construction we have just the opposite. Low emphasis on passive solutions with high mechanical demand thrown at it to compensate. The majority of American homeowners are in this boat and can't just run out and build a super efficient house from scratch. This is where the Nordyne and other such systems can find their market...just make it more affordable, PLEASE! Another poster above (barty) who I believe is overseas says this inverter stuff is much less expensive there. That tells me the price point can drop pretty sharply once there's an educated base of customers here in the USA who can see the true benefits of these systems. Whether the OEM's will do it remains to be seen. It might take a lowballer company who builds decent equipment of this type to bump the high priced OEM's off their lofty perches.

[tpa-fl]

Another poster above (barty) who I believe is overseas says this inverter stuff is much less expensive there. That tells me the price point can drop pretty sharply once there's an educated base of customers here in the USA who can see the true benefits of these systems. Whether the OEM's will do it remains to be seen. It might take a lowballer company who builds decent equipment of this type to bump the high priced OEM's off their lofty perches.

All it'd take is one of the Chinese/Korean manufacturers to decide to make ducted mini-splits and that'd start the ball rolling. Of course, we'd still need the dealers to pass on the savings to the customers. Considering equipment usually doesn't come anywhere near 50% of the cost in a high-quality install by a contractor, the homeowners probably aren't going to see much of a drop in price.

That said, I can't believe how cheap some of the mini-splits have become on the wholesale market. I've even kicked around the idea of throwing one out on the patio for entertaining. Granted, they're no Mitsubishi, but for something like that or a garage, they're ideal.

[Shophound]

All it'd take is one of the Chinese/Korean manufacturers to decide to make ducted mini-splits and that'd start the ball rolling. Of course, we'd still need the dealers to pass on the savings to the customers. Considering equipment usually doesn't come anywhere near 50% of the cost in a high-quality install by a contractor, the homeowners probably aren't going to see much of a drop in price.

That said, I can't believe how cheap some of the mini-splits have become on the wholesale market. I've even kicked around the idea of throwing one out on the patio for entertaining. Granted, they're no Mitsubishi, but for something like that or a garage, they're ideal.

I asked the Daikin rep at our RSES chapter meeting about the U.S. market, how most of the installed base is centrally ducted split systems and that the mini-split might have a slow reception, and if Daikin had plans for that market. He responded yes, Daikin is working on an air handler suitable for centrally ducted split systems common in so many American homes. It seems this would put Daikin in the same playing field now just about singularly occupied by Nordyne...giving competition a boost.

[barty]

I asked the Daikin rep at our RSES chapter meeting about the U.S. market, how most of the installed base is centrally ducted split systems and that the mini-split might have a slow reception, and if Daikin had plans for that market. He responded yes, Daikin is working on an air handler suitable for centrally ducted split systems common in so many American homes. It seems this would put Daikin in the same playing field now just about singularly occupied by Nordyne...giving competition a boost.

Our ex-sales rep (who had come from DaikinUK) was sent out to the US to help kick start the US market and -try- to get the Americans to adopt japanese thinking. Of course he was facing a very steep climb in much the same way that Honda and Toyota did but they are very willing to try and try again so expect the Japanese to have learnt from their mistakes on trying to convert the 'not made here' syndrome by developing a suitable air handler combined with the best of their technology which will leave the domestic market trailing in it's wake..They will also probably have a US plant which will allow Americans to pretend it's American. He did say he had an argument out there with a local who was insistant that Sony was American as apple pie..

He also told us loads of what Daikin had in mind for America and it didn't include being the second biggest seller there either. It took them approx 20 years to get to No/1 status in the UK and I suggest America will be more stubburn but as with your cars,but I suspect it's almost inevitable.

Good luck

The cost of inverters has now driven out almost all standard compressors to the point where unless I look at Fleebay -or the odd Uk manufacturers- I simply can't find any to spec



Cheers

Richard

[Shophound]

Barty, you seem to be thinking what I'm thinking...that the HVAC industry is on the verge of where the U.S. auto industry was back when I first started driving (late seventies)...in the doldrums and rather content about it, until the Japanese came in full force and turned it all upside down. And what precipitated that event? Energy cost concerns. What is going to fuel a sea change in residential HVAC? Same thing. The Japanese answered this event by not only providing gas sipping cars, they ran pretty damn good and held up longer than the American counterpart. They were a tad more expensive than American cars but the longevity and reliability far offset that small difference in cost. Anyone who's ever owned a Toyota with a 22R engine in it knows the story. I drove Nissan pickups for years with the Nap Z 4 engine...it was also a rugged little bugger.

So, if Daikin, Nordyne, and others holding this inverter technology want a little hint; go forth with quality, energy savings, etc....but make it AFFORDABLE!! Right now only the high end market could even look at these systems for what they're being priced at. If these systems are far cheaper yet as effective overseas, it can be done here.

I got to play with the Nordyne demo some more last night. Unless I have a windfall of income it will only be a pipe dream to see such cool technology in my own home. One thing I'm looking at, however, is our local utility is looking at implementing a peak rate structure similar to what I understand occurs in Phoenix, AZ. If so then there's gonna be a groundswell market for higher SEER equipment. People in Texas ain't gonna give up their a/c without a fight! :D

[barty]

Bingo indeed.

yep when the locals see an install which has flare fittings, easy control wiring- Daikin has 1-L, 2-N, 3- 'control interconnect for all functions' a 2 wire full controller,outdoor unit precharged to 30m. High seer, ultra quiet operation,total failure rates below .025% the list goes on and on

Next door installer get a better job done by mid day while you're still holding a superheat charging chart to a torchlight coz it's way past sundown and the penny slowly drops.

I know that the Japanese are aware of the price factor but as it stands they simply don't care to flood the market. The Carrier guy for the high seer inverters recently said that Carrier were reluctant to introduce this stuff (they have had it for years via Toshiba of course) because it's aware of the standard of local engineers.
Simply put Carrier doesn't think Americans are up to the install level required.

http://www.achrnews.com/CDA/Articles/Cover_Story/ca042ea2d95dc010VgnVCM100000f932a8c0____

I read it here with the 'where's the drier?' or the 'liquid line is sweating'. Or the recent 'charge it by sound' line. The overcharging and other abuse these little babies are being subjected to because of the lack of understanding is scary.

http://hvac-talk.com/vbb/showthread.php?t=137783

No I actually feel they are trying to hold the market back because they fear the locals will kill their reputation for quality and reliability by balls'ing up installs left right and centre.
There are some real pro installers here with understanding of the systems currently doing a shed load of work by the book and getting great results but they would be far out weighed by the bashers and crashers doing the old 'git'r'done' which I strongly suspect scares the crap out of them and their warranty dept..

Cheers

Richard

[icemeister]

Sorry to resurrect an old thread, but I mentioned the 23 SEER Nordyne systems to a good restaurant customer of mine who is planning a major renovation of his home and he is very interested.

I have to say I am intrigued with the concept (maybe not so much with the pricing) but I have one area of the system control that is somewhat problematic for me.

As I understand it, these systems are controlled from 118% down to whatever % over a room temperature range of 5 Deg F. I saw this in some spec data on the Nordyne site.

Now I know that I wouldn't like having my own system operate over such a wide range. Heck, the wife and I battle over one degree.;)

Does anybody have any experiences with this aspect of the IQ Drives?

[aircooled53]

http://img237.imageshack.us/img237/8366/m1010acfurn23prqb1.jpg:eek: :cool: :D


The Maytag 23 SEER Air Conditioner/Gas Furnace System must consist of the following components: 23 SEER Air Conditioner, Single-Stage Standard 92.1+ AFUE or 80+ AFUE Gas Furnace, Indoor Coil and an iQ Drive Thermostat.
Up to 23 SEER

Maytag Comfort

The Maytag name promises you dependability and worry-free performance. Now, Maytag also promises you extraordinary comfort and impressive energy savings with its iQ Drive Complete-Comfort System which is quite simply the smartest comfort system available. It's the only system that not only controls temperature, but also achieves the most consistent levels of humidity, air quality and ventilation. And all at the lowest sound levels in the industry.




The Maytag iQ Drive Complete-Comfort System Delivers Total Indoor Air Quality

The Maytag iQ Drive Complete-Comfort System circulates air throughout your home by mixing air from floor to ceiling. Its variable-speed technology creates more uniform temperatures, improved air filtration and reduced humidity levels. In fact, it is ideal for managing the indoor environment in hot, humid climates. With a touch of the iQ Drive thermostat, you can set dehumidification levels from 35% to 70% of the humidity inside the home.

To take total control of your indoor air quality, you can program the iQ Drive thermostat to notify you when it is time to change your filter. Having a clean filter is key to circulating healthier indoor air. If you have allergies and need to remove dust, smoke or other airborne particles, Maytag also offers numerous whole-home indoor air quality products designed to work with the iQ Drive Comfort System.

A key to longevity of any cooling or heating system, is proper maintenance. With the iQ Drive thermostat, you can ask the dealer to preprogram maintenance reminders for indoor-air-quality accessories that you decide to add to your system. A home comfort system is an investment to ensure that your family is comfortable for years to come.


Saving Money and the Environment

While most homes built in the last 10 years have 8 to 10 SEER air conditioners, Maytag has raised the bar to 23 SEER, the highest efficiency level yet in air conditioning. Maytag's 23 SEER air conditioner exceeds Energy Star guidelines for product efficiency. The higher the SEER rating, the more efficiently the unit will perform, resulting in a lower utility bill. You can be rest assured you are doing your part to reduce energy consumption and maximize the efficiency of your home comfort system when you select Maytag's 23 SEER ultra high efficiency air conditioner/gas furnace system.



In addition to reducing energy consumption, our ultra high efficiency air conditioner uses Smart Cool 410™ refrigerant, one of the most environmentally friendly refrigerants on the market today. For more information about Smart Cool 410™, ask your Maytag select heating and cooling dealer.


Inverter Board The Maytag iQ Drive System utilizes inverter rotary technology to achieve the highest efficiency level available today. The inverter board is the brain of the system, while the rotary compressor is its heart. By communicating together, they can condition the air perfectly at all times while using the least amount of energy. Traditional compressors just turn on and off, operating at 60 hertz when running. But iQ Drive inverter technology has almost infinite modulation for a perfectly even variance. And it runs as low as 15 hertz, so it uses less power.
Rotary Compressor

So Quiet, You May Forget You Have It

Thanks to its impressive efficiency, the Maytag iQ Drive Comfort System delivers the lowest sound levels in the industry. Today's traditional compressors operate at 3,600 rpm power. So even with full insulation, sound blanket, sound-absorbing base, lubricated motor and swept fan blade, they make enough noise to be heard inside the home. By comparison, the Maytag iQ Drive rotary compressor can ramp down to 900 rpm for ultra-low power operation and an ultra-low noise level. That makes for a quieter home, especially at night.






Maytag Peace of Mind

Just as you expect from Maytag, this air conditioner offers one of the best warranties available in the industry. The 12-year Worry-Free Limited Warranty on parts as well as the Dependability Promise, reflects Maytag's commitment to you. Participating dealers may also include 12-Year Labor with your product. Ask your select Maytag heating and cooling dealer for details or click on the warranty logo for more information.



High Efficiency and Trusted Dependability

Below are key features and benefits of a Maytag’s 23 SEER ultra high efficiency air conditioner.

This unit is clearly designed for dependability and beauty. The brushed stainless steel cabinet and sleek design protect the coil from yard hazards and extreme weather.
Smart Cool 410™, the earth-friendly refrigerant, enables you to protect the environment better than ever before.
The top and bottom of the unit are trimmed with a charcoal-gray protective silicone coating, which resists fading and corrosion 50% better than comparable units.
The Seasonal Energy Efficiency Rating (SEER) measures how efficiently the unit cools your home. The 23 SEER rating is the highest rating available on air conditioners today.
The permanently lubricated motor offers quiet operation, requires no maintenance and is 100% protected from rain and snow.
The lowest sound levels in the industry.
The one-piece top is designed for maximum airflow and quiet operation.

[Shophound]

I have to say I am intrigued with the concept (maybe not so much with the pricing) but I have one area of the system control that is somewhat problematic for me.

As I understand it, these systems are controlled from 118% down to whatever % over a room temperature range of 5 Deg F. I saw this in some spec data on the Nordyne site.


I'm not quite sure what that means...I can surmise the 118% on down refers to the variable capacity of the system, but not sure what the temp range of 5°F refers to. My understanding is that the compressor, being not limited by a 60 Hz power source, can be overdriven to an extent beyond its nominal rated capacity.

IMO, this technology should be much more widely available for residential systems and not nearly so doggone expensive. Designed and installed correctly, a system that can vary to meet the load as the load varies...that is ideal. No more systems that run out of breath on abnormally hot days. No more systems that fail to dehumidify adequately during warm or cool but humid days. No more systems that can only circulate air at maximum speed, when less volume of air is all that may be needed.

[icemeister]

OK, I'll try to explain how I see it.

All I know about these systems control is what I read about the 5 deg range based on room temperature. That's what bugs me. The 5 deg range.

Let me set up a hypothetical example. Let's say I've got a 3 ton IQ system, the control is set for 75 Deg F and I assume the system will overdrive by 18% and throttle down to 33% (I don't know what the actual minimum is, but bear with me for this example). Here's a chart of what I see this system doing:

Room Temp........76......75.....74.....73.....72.....71
% Capacity........118....100....88.....66.....50.... .33
Tons.................3.5.....3.0....2.5....2.0.... 1.5....1.0

As you can see, at the setpoint of 75 Deg F, we have 100% capacity at 3 tons. If the room temp rises to 76 Deg F we get 118% capacity or about 3.5 tons. Now as the load drops off, we get all the way down to 71 Deg F at 33% capacity and as I would assume, any temperature below that the system would cycle off.

This is what I'm getting at. I want my control system to holding setpoint no matter what. I don't want to spend a gazillion dollars on a system that gives me 75 Deg F on a hot day and 71 Deg F when I wake up in the AM. I can't tolerate that great a swing in temps. My White-Rodgers 1F89-211 holds my old 10 SEER system's temperatures dead nuts all the time. I would only expect the same from the very top of the line stuff like an IQ.

[a\c don]

OK, I'll try to explain how I see it.

All I know about these systems control is what I read about the 5 deg range based on room temperature. That's what bugs me. The 5 deg range.

Let me set up a hypothetical example. Let's say I've got a 3 ton IQ system, the control is set for 75 Deg F and I assume the system will overdrive by 18% and throttle down to 33% (I don't know what the actual minimum is, but bear with me for this example). Here's a chart of what I see this system doing:

Room Temp........76......75.....74.....73.....72.....71
% Capacity........118....100....88.....66.....50.... .33
Tons.................3.5.....3.0....2.5....2.0.... 1.5....1.0

As you can see, at the setpoint of 75 Deg F, we have 100% capacity at 3 tons. If the room temp rises to 76 Deg F we get 118% capacity or about 3.5 tons. Now as the load drops off, we get all the way down to 71 Deg F at 33% capacity and as I would assume, any temperature below that the system would cycle off.

This is what I'm getting at. I want my control system to holding setpoint no matter what. I don't want to spend a gazillion dollars on a system that gives me 75 Deg F on a hot day and 71 Deg F when I wake up in the AM. I can't tolerate that great a swing in temps. My White-Rodgers 1F89-211 holds my old 10 SEER system's temperatures dead nuts all the time. I would only expect the same from the very top of the line stuff like an IQ.

Ice, I'm a certified IQ Drive tech.

The way it works is that the system controller tells the compressor, condenser fan and blower how fast to run in order to maintain the setpoint.

The system can operate anywhere from 30% to 118% of its rated capacity.

There is no temperature swing as there is in other systems since it runs almost all the time but only at a level necessary to maintain the setpoint.

[Shophound]

Ice, I'm a certified IQ Drive tech.

The way it works is that the system controller tells the compressor, condenser fan and blower how fast to run in order to maintain the setpoint.

The system can operate anywhere from 30% to 118% of its rated capacity.

There is no temperature swing as there is in other systems since it runs almost all the time but only at a level necessary to maintain the setpoint.

This makes more sense. Basically it either is or is similar to PID control strategy...modulate the final control devices to hold a setpoint. This is how I would expect a fully modulating system to behave...it ramps up or down to meet the demand necessary to hold a given setpoint.

I have yet to be in a residence with an installed IQ system...once the t-stat is satisfied, does it ramp the system down to a level to hold that level of satisfaction, or does it go ahead and cycle all the way off?

[mark beiser]

OK, I'll try to explain how I see it.

All I know about these systems control is what I read about the 5 deg range based on room temperature. That's what bugs me. The 5 deg range.

I believe you misinterpreted it a bit, which is what I did at first, then I got the training materials. :)

The unit can operate between 40% and 118% capacity.

If the room temperature is within a 5 degree range of set point, 3º above or 2º below, the system matches the capacity to the load. Outside of that range, it works like a normal thermostat, all the way on or all the way off.

If it is up to 3º above set point, it tries to reduce the temperature with as little capacity as possible. It recalculates what capacity it needs to run at every minute, so the faster the temperature is dropping, and/or the closer it is to hitting the set point, the more it will lower the capacity.

Once it reaches the set point, it tries to match the capacity to the load so it maintains the temperature without cycling off.
When it is at the set point, it will look at the indoor humidity vs the set humidity, and lower the blower speed to increase humidity removal. It will keep the blower speed high enough to maintain a coil temperature of 35-37º.
The controller will continue with this until it is up to 2º below the set point.

During all of this, it recalculates the required capacity every minute.

Basically, if you leave it alone you end up with a system that runs most of the time below full capacity while it maintains the set point.
If the humidity runs a little high, and/or its 40% minimum capacity is enough to continue dropping the temperature, it will over cool by 2º before shutting off.

It shouldn't get above the set point unless it is coming off a scheduled setback period, has been off and you turn it on, or you turn the set temperature down.

Because of how it is designed to operate, it is very important that the system not be over sized, or some of the functionality is lost.

Now that I have been through the training material, I can understand why they didn't come out with zoning for it.
Zoning wouldn't really be compatible with the way they want it to operate.

Because it is designed to run nearly constantly, duct leakage is an even bigger issue than with a normal system.
Installing one on an old leaky duct system would be a disaster.

[mark beiser]

Almost forgot, every 30 minutes of run time, the system ramps up to full capacity for 4 minutes for oil return.

Every Monday at 11am, or after every power interuption, it will ramp up the indoor blower to run through a calibration sequence.

[a\c don]

This makes more sense. Basically it either is or is similar to PID control strategy...modulate the final control devices to hold a setpoint. This is how I would expect a fully modulating system to behave...it ramps up or down to meet the demand necessary to hold a given setpoint.

I have yet to be in a residence with an installed IQ system...once the t-stat is satisfied, does it ramp the system down to a level to hold that level of satisfaction, or does it go ahead and cycle all the way off?

The system controller is never satisfied unless the demand is less than the systems minimun operating capability of 30%.

[mark beiser]

The system controller is never satisfied unless the demand is less than the systems minimun operating capability of 30%.

Hmm, the training CD and manuals I have say the minimum capacity is 40%.
I would rather have it be 30% though.

[a\c don]

Hmm, the training CD and manuals I have say the minimum capacity is 40%.
I would rather have it be 30% though.

oops.....................my bad.:o
You are correct Mark, it is 40%.

Not sure if it was wishful thinking on my part or one of those senior moments.:D

[AIR PRO]

Barty, you seem to be thinking what I'm thinking...that the HVAC industry is on the verge of where the U.S. auto industry was back when I first started driving (late seventies)...in the doldrums and rather content about it, until the Japanese came in full force and turned it all upside down. And what precipitated that event? Energy cost concerns. What is going to fuel a sea change in residential HVAC? Same thing. The Japanese answered this event by not only providing gas sipping cars, they ran pretty damn good and held up longer than the American counterpart. They were a tad more expensive than American cars but the longevity and reliability far offset that small difference in cost. Anyone who's ever owned a Toyota with a 22R engine in it knows the story. I drove Nissan pickups for years with the Nap Z 4 engine...it was also a rugged little bugger.

So, if Daikin, Nordyne, and others holding this inverter technology want a little hint; go forth with quality, energy savings, etc....but make it AFFORDABLE!! Right now only the high end market could even look at these systems for what they're being priced at. If these systems are far cheaper yet as effective overseas, it can be done here.

I got to play with the Nordyne demo some more last night. Unless I have a windfall of income it will only be a pipe dream to see such cool technology in my own home. One thing I'm looking at, however, is our local utility is looking at implementing a peak rate structure similar to what I understand occurs in Phoenix, AZ. If so then there's gonna be a groundswell market for higher SEER equipment. People in Texas ain't gonna give up their a/c without a fight! :D

Shophound,
Send me an email, I am interested in what price you were quoted for this system, it sounds like they quoted you "installed price".
My email is in my profile under instant messenger.

[jkish]

Any news on the heat pump version of the IQ drive systems?

[AIR PRO]

Any news on the heat pump version of the IQ drive systems?


Nothing concrete,still in field testing. Looks like spring 2008 from what I am hearing.

[aircooled53]

The original designer if IQ drive system was reported to me as; he was killed in motorcycle accident , and new designers are still working over plans that he had on heat pumps..This is only what I have been told by our rep.

[icemeister]

Thanks guys....especially Don and Mark.....for the detailed control info on these systems. So if I understand this correctly, the system will control to setpoint throughout its capacity range but if the load drops below 40% your room temp will drop 2 Deg F before it will cycle off......and conversely does it cycle back on when the room temp rises 2 Deg F to setpoint or does it have to rise a bit higher?

It would still be concerned about complaints of it getting a little chilly during low load periods....at least I know one woman who would complain.;) :D

[AIR PRO]

The original designer if IQ drive system was reported to me as; he was killed in motorcycle accident , and new designers are still working over plans that he had on heat pumps..This is only what I have been told by our rep.

That is what I was told as well.

[Shophound]

Shophound,
Send me an email, I am interested in what price you were quoted for this system, it sounds like they quoted you "installed price".
My email is in my profile under instant messenger.

I think it was an "installed price". Straight equipment cost I would not know of since I'm a chiller guy who happens to be interested in resi HVAC from a design and performance aspect. Thanks...I'll shoot you an email soon. :cool:

[Shophound]

Hey Air Pro...tried your instant messenger thingie and nothing happens...my email is in my profile if you want to contact me.

[AIR PRO]

Hey Air Pro...tried your instant messenger thingie and nothing happens...my email is in my profile if you want to contact me.

You have mail