Infinity System Issues

[NBeener]

I'm not good at being brief, but ... deep breath ... here goes:

SYSTEM:
58MVC
24ANA
3 zones
Honeywell tru-steam, 6gpd
Skuttle media filter
Lenox healthy climate HEPA

HOME:
Built 2008. R-18 walls; R-50 attic. 2-pane windows.
Ranch.
1900sf main, 9' ceilings
1900sf basement, 9' ceilings

A year into ownership, I changed filters on my HEPA. Noted the model #. Curiosity led me to look at a few things online. Found out it was the HEPA-20. A CHUNK undersized for our home.

He replaced the -20 with the -40.

Our 2nd truSTEAM failed. First one failed in first 90d.

They put the new (identical one) in.

Four days later, it's taken the 25% RH to 31%.

Only.

*I* didn't verify the DIP switch settings, but ... will. Old one humidified with/without heating call.

Similarly, I did a little digging. 6GPD seems WAY undersized for the cubic feet of our (pretty tight) home, in dry, dry Northern Colorado.

Next ... when I was trying to get the truSTEAM to work ... the static pressure self test ran. 1.19" on HIGH fire. Replaced Skuttle filter. SP dropped by only 0.02".

Contractor sent guy to "read pascals" with manometer. HE read 0.48" on high, "the old fashioned way."

Installer says:


The Infinity Control uses an algorithm incorporating watt draw and rpms of the motor. Some times we get accurate info and other times we don’t. For example, if we do not hook up any duct work to the furnace, the blower has very little load against it and it confuses the system from an rpm standpoint on the blower and we get a high static pressure indication.

I'm skeptical.

If the Infinity Controller is -- effectively -- guessing, then it's making a lot of decisions on bad info, compromising performance and efficiency, no ?

So far, I'm VERY impressed with the Infinity setup, but .... sadly ... am losing confidence in the installer.

I'm considering finding a good consultant, to run Manual J, Manual S, and Manual D -- something I never *saw* from the installer (swears he ran them all).

Any of this sound fishy to any of you ?

Time for me to have the system looked at, by different eyes ???

Thanks so much....

[beenthere]

The Infinity control is suppose to be pretty accurate, so I would wonder how the tech only got .48" in high. I'd tend to believe the Infinity control was reporting closer to true static. The tech may not have taken his readings in the right areas. It would be a reading of 119.5 pascals to equal .48".

The 6 GPD Truesteam is underside for even tight 1,200 sq ft homes.

A third party static test wouldn't hurt.

What size is your furnace? Full model number.

[NBeener]

Thanks so much for the reply. I'll let some pictures help me out, here:

Furnace model #: 58MVC080 F-10114

https://lh4.googleusercontent.com/_WVVYjLCNo2w/TVQTlHo_PCI/AAAAAAAABsw/sppgceGy0SU/s640/P1050150.JPG

Humidifier model #: HM506W1005

https://lh3.googleusercontent.com/_WVVYjLCNo2w/TVQTlXXJIfI/AAAAAAAABsU/crPzxgFCePQ/s640/P1050151.JPG

I see four holes that he drilled to run HIS SP tests. Note the plug in each hole:

https://lh4.googleusercontent.com/_WVVYjLCNo2w/TVQTlw2w6FI/AAAAAAAABsc/EV5eIBOpugA/s640/P1050153.JPG

This one's just above the document box
https://lh3.googleusercontent.com/_WVVYjLCNo2w/TVQTmbUlPbI/AAAAAAAABsg/AwFNvoeBvVg/s512/P1050154.JPG

This one's half a foot or so above the "Carrier" badge:
https://lh6.googleusercontent.com/_WVVYjLCNo2w/TVQTtNGhP6I/AAAAAAAABso/XmdCO97qUhQ/s640/P1050155.JPG

And the 4th one:
https://lh4.googleusercontent.com/_WVVYjLCNo2w/TVQTtsBVm2I/AAAAAAAABss/RTpb2TqTpvQ/s512/P1050156.JPG

Every online resource ... including the totally comprehensive Excel Worksheet I found .... calls the 6GPD WAY too low, too, but ... he's now telling me that -- "If anything, that unit is OVER-sized."

:(

Thanks !!

[NBeener]

By the way ...

During construction, I was at the house when the furnace was delivered. He was set to install the 60K BTU version, although the 80K BTU was what was spec'd, and what I had paid for.

I called to speak with him about it.

He said that our house was better insulated than when the original specs were done (sounded reasonable), and that it was a universal Bad Thing to oversize the equipment.

And I get that.

My position, though, was that the MVC should be plenty smart enough NOT to "be oversized," with a continuously variable fan, and a three-stage burner.

He agreed, so ... I have the 80K BTU.

Thinking THAT might be why the SPs are high, on HIGH, I checked the "charts." According to those charts, the duct sizing should be the same for an 80K BTU furnace as for a 60K BTU.

So ... as far as I can tell, that should NOT be the cause of the high SP readings on the controller.

Make sense ?

[George2]

The controler is going to give you the true static pressure.

Thank you for the pictures. I don't see enough of how the return was run, but I'm concerned from what I do see.

Would you be able to give us the duct sizes? Not the grille size, but the duct.

Is the return ALL round pipe? What size is the A/C?

[NBeener]

In the 3-zone system, the:

- main ducts are 10" x 10"
- branches FROM the ducts are 6" dia

The a/c unit is this guy:
https://lh6.googleusercontent.com/_WVVYjLCNo2w/TVQh1VTA3YI/AAAAAAAABs8/8u3oDmAfnRA/s512/P1050159.JPG

Lemme' see what I can figure out about the return....

Thank you !

[NBeener]

I'm not sure about the return sizing. It's a ranch house. The return *grilles* in each room are in 2x4" stud walls, so ... my *guess* would be that they're just using the space between the studs as return air.

If not, can you point me toward ... whatever it is I can take a picture of that will let you know ? ;)

This seems to be the supply. It runs to the outside wall, and reads 6"
https://lh3.googleusercontent.com/_WVVYjLCNo2w/TVQks6iHg2I/AAAAAAAABtM/NCtIYKGguVw/s512/P1050160.JPG

https://lh6.googleusercontent.com/_WVVYjLCNo2w/TVQktWa8MTI/AAAAAAAABtQ/EYgAQDwT_1Q/s640/P1050161.JPG

Here's the back of the mechanicals ... hoping that ... you can see important stuff !
https://lh5.googleusercontent.com/_WVVYjLCNo2w/TVQktsyqENI/AAAAAAAABtU/DGqX0jclHFM/s512/P1050162.JPG

And ... the size of the ducts running to the registers. Measured at 6" dia.

https://lh4.googleusercontent.com/_WVVYjLCNo2w/TVQktxhg4XI/AAAAAAAABtY/q_-L7jI91Yg/s640/P1050163.JPG

[kirbinster]

I found on my unit that you will get the wrong static pressure if you change anything on the system without having it refind all the equipment and run a base static pressure test. Thus, if I close off returns or close supplies I have to have the system go through an install check to find everything and measure the pressures then it will read correctly.

[NBeener]

Interesting, kirbinster. Thank you !

[NBeener]

Okay.

Noticed something else. Might be helpful.

The return air grilles, at each room, are on BOTH sides of the drywall. Can I presume, then, that this provides a pathway to the central "chase," above my stairwell ?

If so, then ... the return duct should be the upper right corner of this picture, right ?

https://lh5.googleusercontent.com/_WVVYjLCNo2w/TVQktsyqENI/AAAAAAAABtw/MZfqEgID4fQ/s512/P1050162.JPG

I'll measure it.

[NBeener]

From the big, high-mounted, central return air grille, there runs a ... maybe 12" diameter insulated flex-duct (looks exactly like the 6" diameter that provides fresh air) into the 16" x 25" box.

Also running into that box are the inputs and outputs for the Lennox HEPA-40 filter.

[George2]

From the big, high-mounted, central return air grille, there runs a ... maybe 12" diameter insulated flex-duct (looks exactly like the 6" diameter that provides fresh air) into the 16" x 25" box.

Also running into that box are the inputs and outputs for the Lennox HEPA-40 filter.

Let me see if I understand. I see the "drop" (the duct next to the furnace) connected to the filter. You are right about the 6" flex to the outside is the "fresh air" intake.

I see from an earlier picture, off the front of the drop, is a galv. pipe maybe 7" in diameter? I assume this goes to a basement return grille?

It sounds like your main house has one large return air grille and the rest are transfer grilles not connected to the system.

Here's the million dollar question: does the 12" flex go from the top of the "drop" to a box in the wall were the grille is?

Do I have it right?

If so, then you are definately short on return. But I still would like to know the A/C size.

Also what size is the centralize return air grille?

[KCA]

If so, then you are definately short on return. But I still would like to know the A/C size.

Looks like it is 2 ton (A-coil) based on one of the pics and the model number in the original post.

[NBeener]

I think it IS a 2-ton a/c unit.

The central return grille is 21-1/2" x 21-1/2"

I think you're right about the rest of the grilles being "transfer grilles." Makes sense.

I'm not *aware of* any basement return grille. I'll look again. It was my understanding that the only sources of supply air for the furnace are a combination of that 21.5" square grille and the outside 6" hose.

The 12" flex sure does go directly up, and almost certainly connects to that 21.5" square grille. I'm simply basing this on ... where that return grille is, and what's *got to be* directly below it.

Thanks so much ... again.

[NBeener]

Ah.

The fatter galv pipe off the FRONT of the drop (I'd guess 8" dia, but will measure it) is the separate 'circuit' for the Lennox HEPA-40 filter !

[beenthere]

The test hole on the side of the furnace, is not a good place to use for static pressure.

The 80,000 does move more air then the 60,000. The 80 needs roughly 1279CFM to maintain a 55° rise in high, and the 60 only needs 959 to maintain a 55° rise in high.

Your A/C is 2 tons, and only needs around 800 CFM. Your duct system may be sized closer to the air flow needs of the house, then the 80,000 BTU furnace.

[NBeener]

The duct feeding INTO the HEPA filter is 10" dia.

The duct FROM the HEPA, INTO the "drop" is 8" dia.

[NBeener]

beenthere: very interesting. Thank you.

What the Carrier docs indicated ... MAX heating airflow ... was:
60: 1070 CFM
80: 1220 CFM

It was THOSE numbers that led me to believe that the ductwork for each should be the same. I found that info here:

http://efficientcomfort.net/Rules_and_Rules_of_Thumb_for_Duct_Systems.pdf

Was it a mistake to use "max heating airflow," then, to assume what size ductwork I needed ?

[George2]

I just looked at the pictures again. There are two (one high and one low) coming off the front of the drop. Where do they go?
Thanks.

[NBeener]

George,

That's the into and out-of for the HEPA filter:

The duct feeding INTO the HEPA filter is 10" dia.

The duct FROM the HEPA, INTO the "drop" is 8" dia.

Thank you !

[beenthere]

Duct work that can move 1070 CFM at a .75" static, will be at .98" if 1220 CFM is moved through it.

That link does tell you about the effect of fittings, and suggest using a .1" FR for duct work. .1"FR is almost never correct.

[George2]

George,

That's the into and out-of for the HEPA filter:

The duct feeding INTO the HEPA filter is 10" dia.

The duct FROM the HEPA, INTO the "drop" is 8" dia.

Thank you !

Thank you for that info. I have never seen one of those before. I'm only aware of the hi-eff. filters on the side (or bottom0 of furnaces or air handlers.

Away, that needed to be clear in my head before we address the reason for the high static in the system.

First, the grille is 20 x 20 inside. That's good for only 800 cfm. Not good.

Second, the 12" (return air) flex carrys about 450-500cfm and it looks bunched. It's getting uglier.

Your total return air cfm (assuming the 6" fresh air is open) is about 550-600?

You shoud hear your blower over revving to compensate for the restriction.

It looks like you could possibly add one BIG return in the basement. Is you basement open to the upstairs?

You need to find someone who knows something. Your guy either doesn't know or he doesn't care. But he is blowing smoke.

[NBeener]

Thanks so much for your help. Your feedback kind of solidified my gut feeling: there's a lot of stuff, here, that simply doesn't look right. Somebody else SHOULD take a look at it.

I met with the actual builder of our home, last evening.

Like me ... he knows enough about HVAC to be truly dangerous, and no more ;)

He's contracted an HVAC mechanical engineer to perform a "blank slate" analysis of our home -- giving her all the information she needs to determine what SHOULD be there, and asking her to do ALL the calcs, and -- essentially -- design a "high-performance" HVAC system for this "theoretical" home.

After that, she'll come to the house, and go over everything, from soup to nuts.

It should take a week or so to get the results.

Once I've met with the builder and the engineer, I'll circle back to this thread, and let you all know what she finds.

Again ... thanks so much !

[by the way: the basement is NOT open to the upstairs]

[George2]

I'll look forward to hearing what they have to say.

Don't mention that you know that the system has about half the return air that is needed.

Don't tip your hand too early, let them tell you. That way you'll see if they have a clue as to how to resolve the problem.

The fact that the basement is not open to the upstairs is an issue that has an easy solution. This would be plan B.

It is the least expensive way to solve the return air short fall.

If someone else is paying for the correction, then plan A is in order. More on that later.

Good luck.

[NBeener]

The mechanical engineer's report is NOT back yet.

But .... I wholeheartedly agree with those of you who believe that my 6GPD truSTEAM is undersized for my 1,900sf house, with 1,900sf basement, both with 9' ceilings.

The new 6GPD was installed on 2/3, to replace the 2nd burned out unit (meaning: I'm now on #3).

Here's the humidity readings since installation. Doesn't look good. The set-point is 45%. I have "defeated" the RH rollback feature (that decreases set RH, when temps drop below freezing), so ... since the installation ... the set-point has remained at 45%.

It also has NOT been below freezing for more than a short time since the 2/3 installation (meaning: just in case my "lock out" OF the rollback feature didn't actually work, it still shouldn't have rolled the set-point back).

DATE/TIME...............%_RH
2/3 14:56....................25%
2/6 9:00......................33%
2/7 22:15....................31%
2/8 17:39....................32%
2/9 17:00....................33%
2/11 17:22..................35%
2/12 15:03..................33%
2/13 9:53....................33%
2/13 13:55..................33%
2/14 18:53..................34%
2/15 12:00..................34%
2/15 17:25..................34%
2/17 8:57...................36%

The longest the old humidifier COULD have been dead was 4d. I keep pretty good track of these things, and ... the actual humidifier is located right by my wood shop. I go by it pretty much daily.

Does this "lack of rise" seem to indicate an under-sized humidifier ... in addition TO the "conceptual" conclusion that some of you came to ??

The humidifier has been on. The hose from the humidifier TO the plenum (is that the right term) IS hot, whenever I check it. The "humidifying" light is always on, when I check.

The installer -- of course -- is asking ME why I'm "just now bringing this to his attention."

:rolleyes:

Thanks !

[George2]

N.B.

I was told not to sell the "True Steam" humidifiers because of "problems."

We carried Honeywell humidifiers but I didn't sell the "steamer."

Why don't you just install an AprilAire 600A (or simuliar) and be done with it.

[NBeener]

Naturally, I think you're right, George, but ... until and unless the installer decides there's a problem -- either that the Honeywell's just a junk unit, or that he undersized the humidifier ... or ... both ... I can't really do anything.

Once the mech. engineer's report comes back, the builder's going to talk to the installer about repairing or replacing anything that was done wrong.

That would include the humidifier ... if her calcs show that IT IS under-sized (I'm betting it is).

Aprilaire is one of my top choices, as is the Autoflo S2020 (http://www.humidifieranalysis.com/autoflo-S2020-EWC.html).

Thanks !

[beenthere]

The S2020 is a 22 GPD humidifier. A new 190 sq ft home(plus basement) shouldn't need a humidifier that big, unless your burning wood and using indoor air for combustion. Or the house is built loosely.

[NBeener]

The S2020 is a 22 GPD humidifier. A new 190 sq ft home(plus basement) shouldn't need a humidifier that big, unless your burning wood and using indoor air for combustion. Or the house is built loosely.

Would the 2000 be more appropriate ?

It's two levels, both conditioned, both 1900sf, and both with 9' ceilings.

2y/o house. Tight construction.

[beenthere]

Since the 6 GPD has been able to get your home up to 31%, the S2000 should be able to reach 40% under the same conditions without any trouble. Presuming that its connected to humidify anytime weather there is a call for heat or not.

Generally there is no harm going to the S2020. Unless you have duct work in an unconditioned space. Then the low air flow of a VS blower may allow the duct to become too cool, and cause condensation in the duct work.

[NBeener]

beenthere:

I'm torn between laughing and crying, about your signature line :)

So ... we've lived in our house since it was built, in 2/09. Over that time ... generally ... it has always maintained an RH of 45%, and done a good job of returning it TO 45% RH, after cold snaps that triggered the RH rollback algorithm (to prevent condensation).

So ... in one sense ... the 6GPD has "worked."

But ... it's blown up/fried TWO units, already, so ... in another sense ... it clearly hasn't worked.

The max time the 2nd unit was inoperative, after this most recent failure, was about three days.

I have great difficulty imagining that our cabinetry and bamboo floors truly lost much moisture IN three days (when I got back from the three-day trip, the RH was at 25%), and even greater difficulty imagining that -- if that WAS part of the problem -- I still would be at only 35%, 15 days after the new unit was installed.

I'm a woodworker (hobby). I know it takes several weeks to see substantial change in the moisture content of woods :)

So ... I only see a couple possible things that would explain the immediate issue:

6GPD is simply undersized
This (the THIRD) unit is defective
Both :(


There are no ducts running in UN-conditioned space, so ... my gut tells me that ... I'd rather err slightly on the size of a bigger GPD figure than a smaller one.

I think I mentioned: originally, I wanted the "whole" Carrier Infinity system, but ... the installer talked me into the truSTEAM.

I'll call the builder, today, and get an updated ETA on the mechanical engineer's report.

My gut tells me ... it's going to indicate a NUMBER of problems, and that insufficient humidification will be the EASIEST of them to fix.

Thanks so much.

[beenthere]

The S2020 will almost seem to effortlessly be able to maintain your humidity.

[NBeener]

beenthere:

Thanks again ... very much.

One more question, please, and then ... I'll try not to bug y'all until the engineer's report is available :)

Do units like the Autoflo S2020 "modulate," so that -- if the unit it [technically] OVER-sized -- you don't run into anything like a "short-cycle" situation, where you find yourself with extremely variable humidity ??

In other words ... is it pretty critical that I get the "right" number of gallons per day capacity, or ... is there some latitude, if I shoot a bit high -- particularly with a "high quality," and "smart" humidifier ?

Thanks again !

[beenthere]

The S2020 doesn't modulate. Its at full output when its on. So its putting .9 gallons of moisture in the air when its on, weather your humidity is 1% below set point or 5%.

Aprilaire's new steam humidifier can be adjusted to 1 of 3 capacities, and I think its highest capacity is 23 gallons a day.

[tedkidd]

My position, though, was that the MVC should be plenty smart enough NOT to "be oversized," with a continuously variable fan, and a three-stage burner.

He agreed, so ... I have the 80K BTU.



Contractor probably did the load calc after being awarded the job. His bid was to someone else's specifications, then he caught their mistake.

Unless you have a crappy house, a huge house, or live in Alaska you probably hurt yourself sticking your nose into your contractors business. Oversized occurs when the outdoor load is too low for the furnace to stay running.

An 80 drops to 30 instead of 22. How much of the season is your load between 22 & 30 - that's when you pay. Is the airflow noisy or uncomfortable? Thats when you pay.

Do you have zone control or internet control? What is that white box? If you have Carriers communicating zoning, oversizing is a HUGE mistake. Ideally your lowest stage is undersized for your smallest zone's airflow requirements. Your monkeying increased your lowest stage by 36%. (Oh no, you have zone control in a 1900sf assumably well built home! A 2 ton multistage heat pump would be really good for that, dropped your lowest output below 18,000. Do some searches on infinity zone control and you'll learn a lot. )

That looks like a pretty nice install but that humidifier IMO was a bad recommendation. Carrier has a nice water saver that is much less expensive to own and operate.

I suspect, since you have a brand new house with very high end equipment instead of the typical bottom of the barrel stuff that goes into new houses that the house is way above average in other areas.

ANYWAY - You are as qualified to determine sizing on your humidifier as you are on your furnace. Again, unless you have a crappy house or a huge house you may need little to no humidity added. Humidifiers are needed when all the moisture created by activities of daily living leaks out faster than it is created. New high efficiency houses sometimes have more humidity added than leaving and have DEhumidifiers running in the winter. (I see - you were able to maintain but assume since it keeps breaking you must need a bigger one.)

(I see you are aware of this as well...) The Infinity will attempt to manage indoor humidity levels based upon outdoor temperatures. This is a fantastic feature - helps prevent condensation, mold, rot, while still maintaining comfort. Unfortunately there is not enough margin in these sales to teach homeowners 3 week class on building performance. The fact you indicated indoor humidity without telling outdoor temperature indicates you have no idea about this.

Was a blower door test done on the house upon completion? Can you post the house's square footage (I see it's 1900 - WAY WAY to small for an 80 IMO - fortunately you didn't mess with AC sizing also!!!), location, and leakage? (This "engineering study" going to include a blower door test?) This should tell a lot.

[George2]

Something that I forgot to mention was that the fresh air intake will have a drying out effect on the house.

There should be a damper in the pipe. Turn it off and see if the humidity level increases.

[tedkidd]

This picture was sent to me by a friend. His house is 3500sf on a windy hill just south east of Rochester NY, built 1999, 2000cfm50 leakage (we took it there from 2900, builder made some pretty big errors). Note outdoor temp and stage.

https://lh3.googleusercontent.com/_1jpVG5c463M/TWFwu-D2h_I/AAAAAAAAiAI/_SlRjOzr4wE/s576/pete%20ost.jpg

He has an mvc060, so output is about 48,000 on a 2f day. Your house is much smaller, and I suspect better built.

The time your contractor invested in performing your load calc cost him more than downsizing from 80 to 60 would have saved him, had you allowed him to to it.

[NBeener]

tedkidd:

Thanks for your input.

My house is 1,900 feet PER LEVEL, times TWO levels -- all conditioned space.

Since both levels have 9' ceilings, my house is 34,000 CUBIC feet.

In two to three days of having a failed humidifier, the normally 45% RH in my house dropped to 25%.

We live in a VERY dry climate, with VERY hot summers and VERY cold winters -- Northern Colorado.

I have severely dry eyes and a long history of sinus problems. The humidity is important to me.

According to my Infinity control, my furnace has spent the following percentages of its working life in each stage:

LO: 68.5%
MED: 28.07%
HIGH: 3.41%

We do NOT have a noisy system. On the contrary, it's amazingly quiet. We have it on the "comfort" setting, looking for longer run times, at lower stages, to minimize temp swings.

As of today (day 17), our home's RH has still only come up 11%.

I'll have to figure out what the white box is. Never looked at/into it, actually. Good question.

George: I'll look for a damper. Thank you !

As to the blower door test: the builder has contracted the engineer; not me.

I don't have much say over what she does or doesn't do, but CAN discuss this with the builder.

I'd imagine that ... understanding how tight the house is ... is ESSENTIAL to understanding issues of equipment sizing, humidifier capacity, and ... nearly everything else.

So far, the builder installed the wrong size HEPA filter, and ... dollars to donuts ... the wrong sized humidifier. I'm not sure taking his side is either the right thing to do, nor terribly objective, at this point :)

[EDIT: it was also MY weeks of homework and headache to figure out that a simple external temperature probe could be installed to stop the sun from creating false temp readings, which was defeating the RH rollback feature, and ... telling us that -- despite the icy driveway -- it was 80*F, outside ;)]

Also, we're at 5,000' above sea level. Carrier recommends "de-rating" the furnace 2% per 1,000' above sea level. I actually don't know whether this was or was not taken into account, initially.

[George2]

NBeener,

Reminder: I'm still waiting to hear what they have to say about your high static reading.

As mentioned before, I think the way they ran the return is far from being right.

George

[NBeener]

Thank you, George.

I e-mailed the builder, to get an update on the status of the engineer's report.

And ... with luck ... find out if she's planning to actually evaluate the house, as it is, rather THAN rely on derived numbers of ... what SHOULD be.

The HVAC guy was supposed to come out ("himself,") to check out the humidifier situation, and to double-check the manometer readings.

But it was a few business days since he said that, and ... no date has been set.

[NBeener]

The HVAC installer told me that he is aware of this thread. We met for several hours, yesterday. With luck, the installer will not take offense to the existence OF this thread, and realize that -- like him -- I'm solution-oriented, and open to solutions, wherever I can find them.

So ... the update:

I have the first draft of the engineer's report back. It's basically Manual J and Manual D calcs. The next step is to compare the recommended duct sizes with what ACTUALLY exists in my home.

In short, we're okay on the furnace and a/c units. Phew !

Yesterday, the installer's manager came out, and spent several HOURS in my house, going through everything, and running numerous tests.

It turns out that my home was spec'd for, and HAD, a 9GPD truSTEAM, and that ... the installation of the 6GPD unit, on Feb 3, was a mistake.

The contractor caught the mistake when he saw the pictures that I posted ON HVAC-TALK ;)

So ... when we receive the Mechanical Engineer's humidification calculations, we'll look at our options for appropriately sized equipment. Needless to say, Honeywell isn't my first choice, at this point.

The very long story made short: the manometer readings (he took many, using multiple locations. I didn't jot all the numbers down) were consistently lower than the Infinity Controller's readings -- with highs in the .68IWC range, against Infinity readings of about 1.05IWC.

The system has been configured to provide a max airflow of 1025 CFM -- below the max airflow of either the 60-14 OR the 80-14.

Apparently, the Infinity uses an algorithm that combines speed of blower motor, current draw, and maybe a few other things to derive ESP.

His Air Handler Flow Meter indicated a CFM slightly higher than the controller indicated (about 10% higher). Current draw maxed out at about 6A, motor only, against a rated 9A, max.

He's going to ask Carrier for a fan curve that charts amps against SP, to try to see what SP the 6A draw SHOULD equate to.

In running the system on HIGH fire, for a while, we saw no rollback of CFM, or lockout of stage. We saw no evidence that -- even IF the system was reading incorrectly high -- it was doing anything as a result of that.

Dampers weren't opening to bleed off pressure, either.

The HEPA filter seemed to make no difference in SP, whether in line, or off line, and whether plugged in and operating or unplugged.

We have a couple of next steps. He's going to talk to Carrier, to

Ask THEM what could explain the SP difference between manometer readings and system readings
Ask for the fan curve that graphs SP against amperage
Understand any risks of high SP system readings -- right OR wrong


Has anybody else seen substantial differences between the Infinity Control SP readings, and values obtained by manometer ? Any ideas ?

We talked about a bypass humidifier, but ... since I have a tankless water heater ... the bypass probably won't require enough flow to activate the tankless. We talked about a hybrid bypass + steam (two-unit) solution. I'm inclined to explore the EWC Autoflo S2000 or S2020, depending on final calc's.

So ... SOME progress.

And ... a shout out TO the installer, for taking the time to methodically go through everything imaginable, explaining as he went.

There ARE some issues, here, but I'm confident they'll get solved.

[beenthere]

Glad to hear they are attending to the issues/questions.

[chloeourdog]

Hi All,

I have this same furnace .... recently installed. Take a look at http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/58mvc-01t.pdf for a good description of how to check static pressure on this unit (Page 38-42) and if you are curious about how the unit determines what stage to run in, read page 44-45.

I had my unit set up (with the installer) to stage with the thermostat instead of the internal algorithm - dip switch setting(s) are explained as well.

[NBeener]

chloeourdog:

AWESOME !

Thanks so much !

Are you running the Infinity Control ? Do you have any reason to believe that there's a difference between the static pressure reported by the Control, and what's measured by a technician (presuming you've ever had this done) ??

Again ... thanks ! I hadn't see this.

[chloeourdog]

I do not have the Infinity control. I just have the Carrier Edge Thermostat (still a good 2 stage thermostat with dehumidification/humidification and hybrid/dual fuel control). I did not get a round to asking for the Infinity control (should have ...)

[chloeourdog]

BTW, I have an April Air 600 (installed back in 2003) that is sufficient for our house (in MD), we are ~1800 Sq. Ft. on the first floor and 1400 Sq. Ft. on the second floor. Basement is currently unfinished. We have a 2nd unit in the attic for the top floor (it is an 80% Infinity 2 stage gas unit w/heat pump). We don't have a humidifier on that unit because it is in the attic.

Our April Air 600 is connected to the cold water supply. With our new furnace I have no problems maintaining humidity. I did have some problems with the previous system (ironically it would draw air from the basement, whereas the new unit gets combustion air from the outside - I think that helps a lot with humidity control because the previous furnace would force the house to draw in a lot of air from outside ...)

[NBeener]

Thanks again.

I've heard very good things about the AprilAire models. It's likely I'd either go with one of those OR the Autoflo unit.

I'm hearing that -- if you cannot heat the water -- you're going to use a LOT of it -- particularly if you set the unit to provide humidity when there's no call for the furnace to make heat.

So ... you either pay for (relatively cheap) water or (not so cheap) electricity (with the steam units). In theory, I could put in a shorty water heater, to provide hot water to a bypass humidifier, but ... that feels like the threshold for "getting silly" ;)

Are your ceilings 8' ?

The extra 12.5% in volume that our 9' ceilings represents ... seems to have a pretty hefty impact....

[chloeourdog]

We have 9' ceilings in the basement (unfinished) and the 1st floor. We are on well water, so we pay electricity to run the pump. I do not humidify unless heat is called for. I think switching to hot water would reduce my water usage, but I seem to be OK with my setup the way it is.

I did purchase a console humidifier for the 2nd floor prior to the furnace replacements, but it does not operate anymore because the house seems to maintain humidity pretty well these days. My console could put out up to 13 gallons a day (don't want to refill it that often though ;)

The April Air 600 is very simple in design.

[tedkidd]

I'm hearing that -- if you cannot heat the water -- you're going to use a LOT of it -- particularly if you set the unit to provide humidity when there's no call for the furnace to make heat.



The extra 12.5% in volume that our 9' ceilings represents ... seems to have a pretty hefty impact....

Impact on what? Air leakage is your humidity problem, unless you are running a DEhumidifier in your basement (dont laugh, seems 1 of 2 homes i audit run dehumidifier all winter).

Height has an effect on stack pressure and therefore leakage, but 1 ft is not significant.

Have you looked at carrier water saver humidifier? NO water waste. I've had great reports from my clients about them.

[NBeener]

Thanks, Ted.

Originally, I wanted an all-Carrier system, so ... I WILL take a look at that.

Doesn't seem like leakage is our problem. The HVAC contractor says our blower-door test showed 0.11ACH.

There are some indications that we may have crossed the line into "too tight," so I want to tread cautiously around the humidification issue, while still hitting the desired set point.

Thanks again.

[tedkidd]

Wow, really tight house!

Wonder why you need to add moisture. Bas is .35ACH. Do you have an ERV? You definitely need one.

[NBeener]

No. We don't have one.

I asked about one, while discussing the HVAC system with the contractor. It was his feeling that it wasn't necessary.

I'm not so sure. I can't know whether he had any idea of the ACH back when we were discussing the buy.

Also, our climate seems to indicate an HRV, but ... I take your point.

I'm actually considering adding a SmartExhaust (http://www.conservationmart.com/p-1185-aircycler-smartexhaust-time-switch.aspx) switch to our guest bathroom fan, in an effort to help with the exchanges....

[tedkidd]

Look into AirAdvice testing. I think you are setting yourself up for potential chronic health issues if you don't provide fresh air.

The hvac guy can't be faulted, he's not building scientist nor really a consultant, he's a salesman hoping not to bog down or risk his sale.

Hrv/erv, depends if you want to recover/reject moisture or accept whatever is outdoors. you can change cores seasonally if recovering or rejecting seasonally becomes important. I think it's more house by house than purely by location. Not sure there is a significant difference. I think you can make too much of it, Either choice is fine.

[NBeener]

Tim-

With posts (can't see my expressions), it's hard to know this, but ... I just have to say ... I like and respect our HVAC installer.

I'm also pretty sure that he didn't know the ACH of our house until it was too late to DO very much about it. I'm sure he's worked on dozens of homes, from the same builder, but I ALSO know that -- since this guy doesn't build cookie-cutter (take it or leave it) homes, probably no two are alike.

So ... I don't blame him ... for anything.

I'll look into that AirAdvice. From the front page of their website, that's a REALLY good recommendation. Thank you.

And ... okay ... HRV/ERV. It LOOKED like the ERV had to be protected from freezing, but ... I guess ... if we installed it in conditioned space (I was thinking attic, but it probably doesn't HAVE to live there), then ... all is well.

BTW: my family roots are half Rochester, and ... I met my wife in the Finger Lakes. I'll likely be back your way, in August, but ... not for anything good.

August. Rochester. If THAT doesn't spell "humidity" .... ;)

Thanks !

[tedkidd]

Design it someplace easy to access. You need to wash the filters and core regularly. Nbd, I take mine into the shower. Getting at it needs to be easy or service becomes repair.