Carrier Infinity Greenspeed System Advice

[vkr]

I will be pulling the trigger on the purchase and installation of a 60,000 BTU Carrier Infinity 98 modulating furnace (model #59MN7A060V17-14) with a Carrier Infinity 20 Greenspeed heat pump (model #59MN7A060V17-14). The AC coil to be included is model # CNPVP3717ATA. Can you confirm this system is matched well for the highest efficiencies?

My home is a 20 year old two story center hall colonial with total square footage of 2200 square feet (2 x 6 exterior stud walls and insulation). Two thirds of the basement is finished and is on separate electric heat.

I am looking for recommendations/suggestions on an Air Cleaner and humidifier. I am interested in a media filter only and was considering an Aprilaire 2410 or a Carrier media filter such as the Carrier model EZXCAB. Will the Carrier filter box marry up better with the Carrier furnace? I’ve had a Carrier EZXCAB in a previous house and was pleased. Does the Aprilaire offer any advantages over the Carrier EZXCAB?

In regard to a humidifier, given I have a hybrid set up with heat pump heating capability, should I go with a steam humidifier to more effectively introduce moisture to the return air? Can you provide some suggestions as to my best option on a humidifier? I was considering either Carrier or Aprilaire. If a standard bypass humidifier is recommended should it be plumbed with hot water given the heat pump set up? Also, ideally I would like to use the Infinity controller to control my humidifier vs hanging an additional controller on the living room wall. Is infinity control of the humidifier easily achieved?

I have metal ductwork with internal insulation. Should I be mandating sheet metal trunk connections with the unit or is the foil covered insulated duct material acceptable?

Also, is it a big deal to request the furnace be connected to the natural gas line with black iron threaded pipe and a union disconnect vs the yellow trac pipe? My previous house install included a trac pipe hook up which looked sloppy given it seemed a 4 foot piece of trac pipe was used for a 2 ½’ application length.

Sorry to ask so many questions of you professionals, but I’m hoping to get a nice clean and “tight” install. I believe establishing a good understanding on the front end can only help. Your help with this matter is greatly appreciated so I can finalize my contract as soon as possible. My Bryant 90 Plus has a cracked heat exchanger and it is tripping the roll out switch on occasion.

Thanks again,

[HAWK 87]

Is the model # for your heat pump correct? I recommend the Aprilaire spaceguard-higher merv. tighter fit. I like the by-pass humidifier (Carrier or Aprilaire, same thing). Aprilaire recommends hot water supply. Definitly use the Infinity controller for your humidistat. I like black iron pipe for gas piping (if the original installation was done in yellow trac pipe, I will remove it and install black iron). The duct work should be sealed and insulated, but, I rarely do it because of $$$$.

Was your old Bryant 90%??? Depending on the model # and year, you may qualify for some $$$$$.

[vkr]

Hawk 87, thanks for your help. My bad, the model number of the Carrier Greenspeed heatpump listed on my quote is model #25VNA036A003. Let me know if this is a well matched system to obtain the best operating efficiencies.

Is the Aprilaire 2410 cabinet metal or plastic? My current 20 year old Spaceguard is plastic. Will the suggested Aprilaire bypass humidifier with hot water hookup perform ok when using the heatpump? Also, can you suggest an Aprilaire model number; my quote does not have that detail.

My current Bryant Plus 90 calculates out to 90.9% efficiency given the input and output BTU’s. The model number is 398AAV036060 and the serial number is 2092A01489. I’m guessing from the serial number it was manufactured in 1989? How do I qualify for some money??

[HAWK 87]

Hawk 87, thanks for your help. My bad, the model number of the Carrier Greenspeed heatpump listed on my quote is model #25VNA036A003. Let me know if this is a well matched system to obtain the best operating efficiencies.

Is the Aprilaire 2410 cabinet metal or plastic? My current 20 year old Spaceguard is plastic. Will the suggested Aprilaire bypass humidifier with hot water hookup perform ok when using the heatpump? Also, can you suggest an Aprilaire model number; my quote does not have that detail.

My current Bryant Plus 90 calculates out to 90.9% efficiency given the input and output BTU’s. The model number is 398AAV036060 and the serial number is 2092A01489. I’m guessing from the serial number it was manufactured in 1989? How do I qualify for some money??

Is your contractor a "Carrier Factory Authorized Dealer"??? They will be able to best match your equipment for you. They should perform a "manual J" load calculation and possible "manual D" for proper duct sizing. From the model # of your old furnace, no red flags are poping up to me.

The Aprilaire 2410 cabinet is metal.

Every home's humidity needs are different. I have a 2 year old Carrier Infinity 3-stage furnace, 2-stage heat pump, Aprilaire 550 humidifier. My home is 44% humidity right now.

Ask your contractor to inspect the secondary heat exchanger. I believe your furnace qualifies for up to $990 off a new furnace. Your furnace is a 1992.

[vkr]

Checking out the Carrier site, one of the three contractors is a Carrier Factory Authorized Dealer. However, they all performed their “manual J” and surprisingly all came up with the same furnace BTU size and heat pump size. My question regarding efficiency was more related to whether the coil was matched properly to the heat pump and furnace to insure I obtain the best HSPF and SEER ratings.

What is the proper procedure to follow on obtaining the up to $990.00 if in fact the secondary heat exchanger has gone bad? Is there really the possibility of a refund on a 20 year old furnace? I was thinking there would be prorated issues coming into play. What’s the best way to obtain any refund that is due? Would my Carrier dealer be aware of the possibility of a refund on a Bryant furnace?

[HAWK 87]

Checking out the Carrier site, one of the three contractors is a Carrier Factory Authorized Dealer. However, they all performed their “manual J” and surprisingly all came up with the same furnace BTU size and heat pump size. My question regarding efficiency was more related to whether the coil was matched properly to the heat pump and furnace to insure I obtain the best HSPF and SEER ratings.

What is the proper procedure to follow on obtaining the up to $990.00 if in fact the secondary heat exchanger has gone bad? Is there really the possibility of a refund on a 20 year old furnace? I was thinking there would be prorated issues coming into play. What’s the best way to obtain any refund that is due? Would my Carrier dealer be aware of the possibility of a refund on a Bryant furnace?

I cant answer your coil question. Dont know.

Ask your Carrier dealer about the secondary heat exchanger warranty. I'm sure they have already checked the secondary to see if it has failed. If its bad, it qualifies for $540.00 or $990.00 off the price of a new furnace (depends on the serial # weather you get $540 or $990).

[superfittertech]

HSPF and SEER ratings

AHRI certified reference # IS 4702003
you can find it at
http://www.ahridirectory.org/ahridirectory

HSPF=12.2

SEER= 18.9

That's 2nd highest combo using CNPVP3717ATA coil. Highest uses a CNPVP4821ATA coil. HSPF goes to 12.3, but cool cap goes from 34200 to 33800 BTU'S. seer remains the same and 4821 coil is 21" wide vs 17" wide

AHRI certified reference# 4702012

As for Media filters I recommend and install the Airbear right angle media filter cabinet. It uses a 20"x25"x5" filter and it is also a metal cabinet


Humidifier

Aprilaire Model 600 bypass or 700 power and yes definitely use hot water

[vkr]

Hawk 87 and Superfittertech, Thanks so much for your expert guidance. I have one more question in regard to the Carrier Greenspeed heat pump. I understand the exit air temperature that this heat pump puts out is slightly higher than other heat pumps. Is that true? Also, can you give me an idea of the outlet air temperature of a Carrier Greenspeed, a standard heat pump, and a Climatemaster Tranquility 27 geothermal heatpump? I just don't have any experience with heat pumps and am curious as to the exit air temperatures and differences.
Thanks,

[gravity]

i would ditch the furnace and go with a 2 stage variable speed.

have the installers make it so only high fire works.

any modulating furnace is a waist of energy. when they fire into low stage that actually waist more energy and take longer to heat your home. in low stage you might get 40% efficiency out of it.

[vkr]

Wow, can you or someone educate me a bit more in regard to modulating furnaces being a waist of energy? Is this when they are operating at lower outputs or all outputs? I'm also confused by your suggestion to go with a two stage furnace and have it installed so only the high fire works. If that is more economical, why would I even purchase a two stage furnace? I'm totally confused by your comments, please clarify this for me.

Thanks,

[second opinion]

Wow, can you or someone educate me a bit more in regard to modulating furnaces being a waist of energy? Is this when they are operating at lower outputs or all outputs? I'm also confused by your suggestion to go with a two stage furnace and have it installed so only the high fire works. If that is more economical, why would I even purchase a two stage furnace? I'm totally confused by your comments, please clarify this for me.

Thanks,

I think somebody got in the wrong coo laid last night. Modulating is fine and will give you better comfort control. slightly less efficient on the fuel burning but less cycling and a more constant steady state efficiency run time out ways the other.

[isuredo]

looks like they have bid you the best your goiing to find, as far as humidifiers, check out the aprilaire 800 steam humidifier, with the high outlet temps of your gas furnace a steam humidfier is the way to go and the best way to introduce into your home

[gravity]

i feel that variable speed blowers are very nice and efficient. you can only get a variable speed motor on a 2 stage furnace. if your house needs a 100,000btu furnace, why would you want a modulating furnace that is going to try and heat it with 40,000 btu?

with a modulating furnace you supply temps are going to be lower as it modulates down lower.

a single stage furnace or a 2stage wired up for single stage is going to have shorter run times and cost lest to operate.

i've already had plenty of customers complain that their 2 stage furnace doesnt seem to heat enough and the costs of gas never went down. it may have gone up or stayed the same.

customers with modulating furnaces say that the air comes out is not as hot and it seems to run long cycles.

i dont know about you but when my heat comes on i dont want it blowing cold air for a long time. i want hot air and it to run the least amount of time.

[superfittertech]

I think somebody got in the wrong coo laid last night. Modulating is fine and will give you better comfort control. slightly less efficient on the fuel burning but less cycling and a more constant steady state efficiency run time out ways the other.

x2

[skippedover]

i feel that variable speed blowers are very nice and efficient. you can only get a variable speed motor on a 2 stage furnace. if your house needs a 100,000btu furnace, why would you want a modulating furnace that is going to try and heat it with 40,000 btu?

obviously a little education is needed here. If you were to do a load analysis on a house and use a design temperature of 50°F, would the heat loss be the same as it would if we did a loss on the same house with a design temp of 5°F? The answer is, "No" and the expanded answer is that at 5°F the house will need substantially more Btu's per hour than at 50°F per hour. Knowing that, if you size the furnace for 5°F, then it's clearly over sized at 50°F. Do you agree? So if I fire up a 1-stage furnace (regardless if it's a 2-stage wired for 2nd stage only) at 50°F, it will run a short time because it's putting in Btu's at the rate of (98% AFUE) 98,000 Btu's PER HOUR or 1,633 Btu's PER MINUTE. Now let's look at the 100,000 Btu 98% AFUE modulating furnace. It slows down to 30% of full output, thus it's output is 29,400 Btu's PER HOUR or 490 Btu's PER MINUTE. Now which furnace runs longer? Right, the modulating. And which one cycles on/off/on/off during the hour? Right, the 1-stage. So the modulating is much more comfortable for the customer because it's on almost all the time, on/on/on/on with continuous heat. Is the combustion efficiency lower than when it's a full fire. In my experience, yess it is but only bay about 1.5%. That's not enough to buy you a hamburger once a year in real terms. So high efficiency staging or modulating does what it's supposed to do. That is, deliver longer heat cycles so the customer is more comfortable.

with a modulating furnace you supply temps are going to be lower as it modulates down lower.

Not true. The variable speed blower also slows down, thus leaving the air in contact with the heat exchangers for longer period of time and allowing the air to reach the same temperature it does at full output.

a single stage furnace or a 2stage wired up for single stage is going to have shorter run times and cost lest to operate.

See my comment above about efficiency. The staging and modulating is, again, all about customer comfort and after all, the whole point of installing the furnace is for the customer's comfort, isn't it?

i've already had plenty of customers complain that their 2 stage furnace doesnt seem to heat enough and the costs of gas never went down. it may have gone up or stayed the same.

A multi-stage or modulating gas furnace does NOT save money by operating at a less than maximum output. It's not about efficiency. It's about comfort. Longer heating cycles (if properly sized and you DO do a load analysis for each job, right?) that keep the customer comfortable. It takes the same number of Btu's to heat the house at a given outdoor temperature. The only difference is whether those Btu's are delivered in 10-minutes out of and hour or 60-minutes out of the hour. Once the loss from the house meets or exceeds 30% of the design temperature, the modulating furnace never shuts off. We refer to that as continuous heat.

customers with modulating furnaces say that the air comes out is not as hot and it seems to run long cycles.

Long cycles. Now you're catching on.

i dont know about you but when my heat comes on i dont want it blowing cold air for a long time. i want hot air and it to run the least amount of time.

You're entitled to your preferences but I've yet to meet a customer who wanted hot/cold/hot/cold when the would have warm/warm/warm/warm. Different customer base? Maybe. Or maybe it's that I do a load analysis and properly size the furnace for each job.

[gravity]

a 2 stage or modulating furnace maybe used for comfort/zoning but its going to burn more energy. maybe the home owner has tracked his fuel usage and can share with us in a year if he has saved any money. if you know how to calculate thermal efficiency the numbers prove that a 2 stage/modulating costs more to operate.

[superfittertech]

a 2 stage or modulating furnace maybe used for comfort/zoning but its going to burn more energy. maybe the home owner has tracked his fuel usage and can share with us in a year if he has saved any money. if you know how to calculate thermal efficiency the numbers prove that a 2 stage/modulating costs more to operate.

minimal at best, plus more than likely replaced a lot lower efficiency furnace.

[chuckcrj]

I think somebody got in the wrong coo laid last night. Modulating is fine and will give you better comfort control. slightly less efficient on the fuel burning but less cycling and a more constant steady state efficiency run time out ways the other.

Gravity is correct, a properly sized mod furnace will burn more gas in a year than a properly sized single stage furnace, all other things being equal.

Have you ever measured the thermal efficiency of a mod furnace on low fire? It will surprise you. And I don't mean watching the eff reading on an analyzer, I mean actually measuring it.

[vkr]

Skippedover, thanks for your thorough explanation of the modulating furnace operation with a variable speed blower. It seems there is agreement that efficiency is lost at lower output BTU's. It would be nice if the furnace manufacturers posted some efficiency information at various BTU outputs, or an efficiency chart for varying BTU output. If I understand correctly, the Carrier Infinity 98 is 97.? percent efficient at max output, but I couldn't find any additional efficiency data at lower outputs.
Thanks to all that contributed

[skippedover]

Skippedover, thanks for your thorough explanation of the modulating furnace operation with a variable speed blower. It seems there is agreement that efficiency is lost at lower output BTU's. It would be nice if the furnace manufacturers posted some efficiency information at various BTU outputs, or an efficiency chart for varying BTU output. If I understand correctly, the Carrier Infinity 98 is 97.? percent efficient at max output, but I couldn't find any additional efficiency data at lower outputs.
Thanks to all that contributed

You can't find the data because it's insignificant. We're not talking dropping to 80% from 97%. We're talking 96% or maybe in an extreme case 92%. But let's address the real issue here. Most manufacturers and Carrie/Bryant used to be no different, will advertise their MAXIMUM efficiency on a rated piece of equipment installed in the most energy efficient position (upflow, downflow, horizontal left or horizontal right). If you select a different model or install it in a different position, then you could lose 1-5% off the advertised rating immediately, absent any staging or modulation. The new Carrier/Bryant products are now quoting the LOWEST efficiency you can expect of all the sizes and positions. So again, the WORST efficiency at high fire is what they're advertising. In addition, the Carrier Furnace is rated 98% and the Bryant, the identical furnace, is rated at 97%, just for marketing advantages for the Big Blue Oval. So hanging your hat on any specific efficiency is fools gold. It's just a laboratory test and just like the mileages posted for automobile efficiency and stock performance over prospectus, your results may vary.

Shucks, you'll suffer much more significant losses than combustion efficiency if your ducts leak 5% or more or ducts are under sized and the blower needs to run at .8 IWC static pressure. The differences of modulating and staging efficiency versus high fire is a red herring. There are many places to put your attention to gain back any small loss on that issue. They are designed for greater comfort and deliver significantly more comfortable homes when properly sized and installed. The results for clients when installed by a company that does not perform load analysis and cuts other corners during the installation are likely to be less than stellar. And that's a fact.

[vkr]

Skippedover, Thanks for your reassuring comments regarding the efficiency rating. It is comforting to know that the efficiency does not drop too much below the 97% rating when running at various outputs.
I'm close on finalizing this system, but I have two additional questions:

Although, I'm only heating approximately 2,200 square feet and forgetting about the additional electric cost for the moment, would an Aprilaire steam humidifier maintain a better humidity setpoint than say an Aprilaire bypass humidifier?

My authorized dealer includes a 5 year parts warranty on my system, but offers (for additional money) a Carrier 10 year parts warranty/limited lifetime warranty on the heat exchanger. Is it worth paying for this Carrier 10 year warranty given the cost is significant? I'm currently thinking it is not given my past good experiences with the Carrier brand. Let me know your thouhts on the above two questions. Thanks !

[Freezeking2000]

Skippedover, Thanks for your reassuring comments regarding the efficiency rating. It is comforting to know that the efficiency does not drop too much below the 97% rating when running at various outputs.
I'm close on finalizing this system, but I have two additional questions:

Although, I'm only heating approximately 2,200 square feet and forgetting about the additional electric cost for the moment, would an Aprilaire steam humidifier maintain a better humidity setpoint than say an Aprilaire bypass humidifier?

My authorized dealer includes a 5 year parts warranty on my system, but offers (for additional money) a Carrier 10 year parts warranty/limited lifetime warranty on the heat exchanger. Is it worth paying for this Carrier 10 year warranty given the cost is significant? I'm currently thinking it is not given my past good experiences with the Carrier brand. Let me know your thouhts on the above two questions. Thanks !

Steam is a big energy hog!

Go with a Bypass flow thru.

I think all carrier units comes with 10 years parts. They should be talking about 5 and 10 year labor. Buy extended labor coverage with new technology if you are not moving.

[vkr]

Freezeking2000, you are correct. It is a 5 and 10 year labor extended coverage plan. Your "new technology" comment definitely is a good point given the new greenspeed inverter (is it) in the heat pump.

Any other advantages or disadvantages when considering steam vs bypass humidification?

[vkr]

So now that I am going with a Carrier Greenspeed Hybrid system (modulating gas furnace and Greenspeed heat pump), how do I determine when to use natural gas or electric heat pump to heat the house?

My system HSPF = 12.2 and the SEER = 18.9
Modulating gas furnace efficiency = 97.4%

Including distribution charges, my natural gas cost is currently $1.03 per therm. My electric rate including distribution charges is 12.7 cents per kilowatt hour. I realize that at some outdoor temperature I will have to switch over to gas. However, is there a chart or can I create a chart to determine when to switch over to gas vs. using the electric heat pump? Recall, I am in the Harrisburg, Pennsylvania area (south central PA).
I'm trying to understand this so I can utilize the hybrid system to my advantage as utility prices change in the future.
Thanks !

[beenthere]

Need to know the BTU output at various outdoor temps, or atleast at 47 and 17, along with the COP of the heat pump at those temps to do a balance point graph.

I may have blotched my math. But at the rates you posted, and the efficiency you posted for the furnace. I come up with the heat pump costing more to use anytime its COP is below 3.54, which makes it just about useless for savings on your heating bill.

[skippedover]

You've got a very low natural gas cost/therm and a not so low electrical purchase rate. Since the GreenSpeed is a heat pump, you can mess with it in heating/hybrid heat if so desired with the high HSPF it obtains (about 13) but comfort is or should be the biggest consideration. We have always gotten rave reviews on the mini-splits with variable outputs and I expect no less from the Carrier/Bryant and other manufacturers variable speed units.

[beenthere]

HSPF doesn't mean much with his rates. With the high COP he needs for the heat pump to save him money on his heating bill. Even with its COP of 3.8, it will only save him $0.71 per 1,000,000 BTUs of delivered heat.

[vkr]

So, are we saying that at the current natural gas and electric rates in my area that I have nothing to gain with the Greenspeed heat pump? Should I be focusing on a high efficiency Infinity air conditioning unit instead of the Greenspeed heat pump to save on installation costs? Possibly my SEER number could even be improved with AC only?

Should I be pushing my installer for this evaluation since it seems we (Skippedover) are missing some of the required information?

Currently, in my area we are enjoying reduced pricing on natural gas given the "fracking" that is taking place in north central Pennsylvania. Of course, this could change in the future, but is it worth paying extra for a Greenspeed heat pump if costs do not vary much for years to come?

Thanks for your help on this issue. I know I am asking a lot of questions and I really appreciate the help and guidance. Just when I thought I had my purchase defined . . .

[beenthere]

Ask your contractor to show you a savings/ROI chart.

You have to decide how confident you are your gas rate will stay low, and that your electric rate won't go up.

Look at your heating bill for last winter(not this warm winter). Convert it to therms, and then at $0.071 per therm savings. Figure how many therms of gas a year it would have to save for you, to recover your cost in 10 years.

[gravity]

SEER, HSPF, and AFUE are pretty much bogus efficiency numbers. Maybe you can google it and find some good reads.The real numbers you should be concerned about are COP, EER, and thermal efficiency. A heat pump would be a nice feature to consider. Say the ignitor broke on your furnace. You would have a backup heat. Say the heatpump fan motor died. you would have gas backup.

[beenthere]

SEER, HSPF, and AFUE are pretty much bogus efficiency numbers. Maybe you can google it and find some good reads.The real numbers you should be concerned about are COP, EER, and thermal efficiency. A heat pump would be a nice feature to consider. Say the ignitor broke on your furnace. You would have a backup heat. Say the heatpump fan motor died. you would have gas backup.

Say the indoor blower died. You have no heat.

[gravity]

Say the indoor blower died. You have no heat.

:LOL: this is true

[vkr]

OK, at current gas and electric rates it is becoming evident that I don't save much of anything running the heat pump instead of the gas furnace. Therefore, I have to look at this and decide whether the variable speed compressor and any additional dehumidification/comfort it may provide is worth the additional $$. Given we also are used to/prefer to set back the temperature during the heating season is the heat pump even for me given the minimal savings.
Comments are welcome to help me sort this thing out. Thanks ! :gah:

[beenthere]

Only if you think your gas rate will go up disproportional to your electric rate.