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Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold Area

Posted by Sabs83 (My Page) on
Mon, Feb 18, 13 at 1:17

Hello and thanks in advance!

I live in Massachusetts and have been quoted to have installed the Carrier Greenspeed 25VNA Heat Pump as my sole heat source.

It would replace a 26 year old oil furnace...

Please post electric usage with regard to the Carrier Greenspeed 25VNA Heat Pump (before and after install would be great!)... Please also post what temp you keep your house at, how much square footage it is and how well it is insulated...

Thanks!!!!!

Thanks!!!!


Follow-Up Postings:

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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

I can't help you on electric usage. You may refer to other thread from Charley who apparently is satisfied.

However what size GreenSpeed condenser are you looking at? And what mdl air handler? This can make a big difference in efficiency numbers which of course will help you on your electric operating costs especially in heat mode.

IMO


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Sabs83

You would do well to choose the Greenspeed system and get rid of your oil furnace. Even at the contractor’s projections and at today’s oil prices you would see a payback within 4-years. You would also have greater comfort particularly in air-conditioning mode.

Other considerations are the age of your oil tank, oil tank replacement as demanded by either your insurance company or oil supplier and liability should it leak to name a few.

Get rid of oil, replace it with the 3-ton Carrier Infinity Greenspeed you mentioned and don’t look back!

SR


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Thanks so much for the messages already! Sorry for the delayed response...

tigerdunes:

According to the contractor I need "The house requires 30,000 btu’s of heat and 18,000 btu’s of cooling"...

Does that answer your questions?

I meet with the contractor tomorrow to ask more questions and answer concerns... I will ask those specific questions tomorrow and post...

fsq4cw:

Do you have or know anyone with the Carrier 25VNA? Any thoughts on how to predict electric usage or to find studies that someone/Carrier/other company has done with regard to 25VNA?

What do other heat pumps (sole heat source) cost to run in terms of KwH's?

Thanks!!!!


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Sabs

What size condenser was quoted and what size/model air handler was quoted?

What size heat strip?

What is your location?

Post back.

IMO


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

The best way to have your questions answered would be to ask for Greenspeed references from the installers that provided your installation proposals, as the cost of operation and potential savings will vary with regional energy rates and climate.

What I can tell you is that it has been our experience that Greenspeed is the next best thing compared to geothermal.

Here are some facts that may be of help to you.

As tested by ‘Natural Resources Canada’, ‘Office of Energy Efficiency’ which is an independent federal government agency, as tested in Region V, the Carrier Infinity Greenspeed (2 or 3-ton) has a HSPF of 11.30, an average COP of 3.31 and compared to an electric furnace will consume 69.8% less energy IF the Greenspeed is providing 100% of the heat required. Carrier claims a COP of 3.8 and a savings of 73.6% for an average temperature in Region IV, center north United States. Based on Natural Resources Canada’s findings, this seems reasonable.

Here are some facts and figures from a long term in depth case study (June 2011) by Carrier done in Quebec.

Balance point +4F for a 3-ton Greenspeed in the Montreal Canada region of a 3,000sq ft cottage. Based on local BIN data, hours of operation were 1,866 in A/C & 6,894 hours of operation heating. Heating mode, total 19,063kW, HP 18,146kW, and backup 916kW. Heat pump provided 95.2% of total heat. (That is very close to what is expected of geothermal in this region!)

Cost savings compared to an electric furnace were 66%, compared to oil 79% with oil costing $1/litre.

If your average winter temperature is about 26F, you could expect to save about 65% as compared to an electric furnace.

BTW: Feb. 13, 2013 price for heating oil, Montreal Canada ~$5.22/USgal! It’s hard to believe people are still heating with oil with furnaces running at about 65% efficiency; I don’t get it.

SR


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

I live in Massachusetts.

The Carrier outdoor model is 25VNA024A0030

The Carrier Indoor model is CNPHP3617CA

I asked contractor what the condenser size and what mdl air handler was --> Condenser is 36BTU and model air handler is Carrier FE.

I am googleling 'Natural Resources Canada’, ‘Office of Energy Efficiency’ now...

Thanks for all the help!


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

The outdoor condenser you listed is a 2 ton model.

I would like to know the full model number of the air handler. And yes, it does matter. Of course you will need the Infinity controller.

I would want the 9 KW prewired staged heat strip. Accept this only!

IMO


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Update:

Gross Cost = $19,000 (Net after rebates= $16,350)

Equipment:
- Carrier 25VNA036A003 --> 3 Ton Variable Speed Heat Pump
- Carrier FE4ANF005 --> Variable speed high efficiency fan coil
- Carrier Programmable thermostat
- Carrier KFCEH1601315 --> 10 kw electric heater, 2 stages (5kw,15kw)

System efficiencies: 20 seer, 14 eer, 12.4 hspf

Work includes:

-Remove and dispose of oil furnace, oil tank and metal chimney.
-Installation and connection to existing duct work.
-Install new insulated steel duct work up to second floor with supplies into 3 bedrooms. (current duct work is not getting any flow)
-Install new floor return grille on first floor.
-Concrete pad for heat pump.
-All power and control wiring from existing service panel.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Thats a similar quote that i got for the system.
Carrier Infinity 20 SEER 13 HSPF Greenspeed Cold Climate Heat Pump with Perfect Heat and Humidity Control to replace an existing oil furnace was 13k which included MA sales tax.

It sounded great but the installer had never installed this particular unit before so I was hesitant. Also on the furnace reviews website there were some conflicting reviews in terms of reliability.

Lastly I was hesitant on the noise level as it was going to be located outside our bedroom windows (as opposed to our oil furnance which was inside the middle of the house).

If you do go with it please post some pictures or videos so we can know your experience.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Well I pulled the trigger on the 25 VNA. Thanks for the information!

Does anyone know how to set the outdoor temperature at which the heat strip turns on to supplement the Heat Pump??

Have you found that keeping the thermostat at a steady temperature is the most efficient or do you set the temperature back when you are not home or asleep? If you set back, how many degrees do you set back?

Any other pointers for a newbie like myself?

By the way, both in heat mode and a/c the system is shockingly quite!!

Thanks again!!


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

The temperature the auxiliary heat strips are energized is in the Infinity Controller service menu. The contractor should have set this up for you. If you know the model number you do can do a search for the installation manual and try to change it yourself. You have to be careful when making any changes.

Large set backs are not recommended for heat pumps. One reason is because you don't want the heat strips to turn on during the recovery period. This wipes out any savings and could actually ending up using more electricity. In heating mode don't use more than a 3-4 degree set back. I turned off the smart recovery on my thermostats. The default is on from the factory.

In cooling mode use the same 3-4 degree guide line. On hot days it takes a long time to recover and it becomes more of a comfort issue than savings.

Enjoy your Greenspeed heat pump.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

I would go no higher than 3 degree setback and maybe not that if your load is very close to BTU output on heating.

For that system, I would lock out heat strips for auxiliary above 25 degrees. Then watch system's performance and adjust as necessary. You will have a long wait though.

Post back next winter.

IMO


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Thanks Mike and Tiger!

I have the Infinity control model SYSTXCCITW01...

Looking up the manual and trying to find out how to get back into the Setup mode and what option to change... :)


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

I figured out how to enter setup mode and change the settings....

Hold the "service" button down for ten seconds and you enter the install/options screen....

It was there you can play with the heat pump options and prevent the secondary heat source from coming on until X degrees outside!! :)

I set it at 10F but the Manufacturers manual even says it has the ability down to -30F. It will be a learning season.... Haha!

Thanks again for the help!!


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

You could experiment and set the backup to come on at 4F. You should have a constant output of about 102F until outdoor 4F. Then it drops off to an output of about 92F at outdoor 0F.The bigger question is what’s the heat loss of your home at those temperatures; what’s you’re home’s balance point with this system?

Time will tell; post back when you know.

SR


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

If the auxiliary heat is not activated during a set back recovery, and the output is 102 degrees F up to an outdoor temperature of 4 degrees F, then is there any down side of having a bigger temperature set back?


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

I would want to know the BTUs at that low outside temp. It is difficult for me to believe one would get that high of supply temp at that low outside temp.

Perhaps some GreenSpeed pros and homeowners can share their expertise and experience.

The beauty of the GreenSpeed and the main selling point is on the heating side. The GreenSpeed holds its BTU output for the rated size at much lower outside temps than convention air source heat pumps. Perhaps this is the breakthrough that the Hallowell never really achieved. Feel sorry for those customers who bought that system.

IMO


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Re: mike_home

“If the auxiliary heat is not activated during a set back recovery, and the output is 102 degrees F up to an outdoor temperature of 4 degrees F, then is there any down side of having a bigger temperature set back?”

Aux heat should not be activated with the ‘Smart Recovery’ mode of the Infinity thermostat so there may not be any disadvantage to reasonable setbacks. However I wouldn’t get too creative when it’s 4F and windy outside.

We heat our home with a geothermal HP and it has to be colder than ~-10F and windy outside before we have to use the backup. We never use setbacks; just leave it at a constant 70F.

Re: tigerdunes

“I would want to know the BTUs at that low outside temp. It is difficult for me to believe one would get that high of supply temp at that low outside temp.”

The data I provided in my previous post came from a ‘Power Point’ presentation for dealers that was produced and copyrighted by Carrier Canada.

According to another graph in the presentation, the 3-ton 25VNA at 7F produces 22MBtu; the 4-ton 25VNA at -4F produces 28MBtu.

However, to be honest, common sense and living in a cold climate tells me no house with a 4-ton HP will be at or above its balance point with 28MBtu at -4F - unless it’s very tight and well insulated, most improbable!

According to the same graph the 4-ton HP seems to put out its full 48MBtu down to 14F.

SR


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

"Aux heat should not be activated with the ‘Smart Recovery’ mode of the Infinity thermostat "

Are you sure about this? What happens if the heat pump can't put out enough heat to satisfy the temperature set point during the recovery period?

Setting back temperatures has been proven to save energy. How much energy is difficult to predict since it is highly dependent upon on many factors. I understand set backs on a conventional heat pump can be counter productive. But it seems the inverter class of heat pumps could change the amount of set backs during the heating season.

I am not sure what the definition is of a reasonable set back temperature. I would define reasonable in the amount of time it takes to recover and not so much the temperature differential.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

“Aux heat should not activated with the ‘Smart Recovery’ mode of the Infinity thermostat”

“Are you sure about this?”

The operative phrase is ‘should not’. It may take a few cycles for the thermostat to ‘learn’ and as you say, if it can’t keep up, the backup will come on. The Infinity system does monitor outdoor temperature at the HP coil.

Set backs seem to be most effective with dual source systems, heat pumps and oil or gas furnaces for backup. I personally feel that setbacks may be most effective during ‘shoulder’ seasons, when a heat pump has a chance to recover without running for many hours to recover. I would not recommend using them in the dead of winter in a cold climate if the HP has to run for 5-hours or more to ‘catch up’ when the back up can do it in about an hour.

I’ve just installed a 4-ton Carrier Infinity Greenspeed a couple of weeks ago not far from my home with permission to monitor the utility meter. Next winter should tell the tale.

I would agree with your definition of ‘reasonable set back temperature’.

SR


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

A little update regarding summer usage and cost:

I live in Massachusetts and had the 25VNA installed around May 20, 2013. I pay .15 per KWH. I left temp between 72-75 F.

June = 130 kWh = $19.50
July = 301 kWh = $45.15
August = 132 kWh = $19.80
September = 52 kWh = $7.80

I will update after winter and report on heating costs. One observation so far:

I set the secondary heat source (heat strip) to come on only if the outside temp is less than 10F however the secondary comes on when the system is defrosting (I think so but since I've only witnessed it once I can't say for certain). Not sure if you can prevent the secondary source from coming on then. I'd prefer it if you could stop the secondary heat source until the defrost has finished then have the HP bring the temp back up to your setting. The inside temp can't go down that much during defrost cycle... Thoughts or suggestions??

Thanks!


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

You were able to keep you house 72 -75 degrees in August for only $19.80? The numbers sound a little too good to be true.

How did you separate the electricity usage of the Greenspeed versus the rest of the house?


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

The easiest way to ‘lockout’ the backup from activating in defrost mode would be to turn the backup breakers ‘Off’. If there are separate breakers for the multiple stages then you could select which stages to ‘lockout’ via the breakers.

It may not be advisable to do this lockout at all as there will be no backup at all not only for defrost mode but more importantly if there should be a compressor lockout while you’re away from home for an extended period of time, such as on holiday. Besides, the backup is always staged so that you’re using the minimum number kW.

I would also consult Carrier or your dealer to find out if disabling the backup during defrost mode voids your warranty for any reason what so ever. You may be ‘on the hook’ for any service call while operating in this mode if it’s not an acceptable practice. So much for trying to save a few bucks - particularly if you’ve been away and pipes burst!

SR


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

You might be able to do the defrost backup lockout via the T-stat but the manual is a bit ambiguous.

See page 36 of the installation manual for the T-stat.

SR

Here is a link that might be useful: Infinity T-stat manual


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Hello Mike_Home. The infinity control thermostat keeps track of it for you and you manually put in what you pay per KWH. I was also able to verify somewhat from last summer's electricity usage as well. The control has some great data on usage (per day, month and year plus it will do the math for you to see the cost).

fsq, I'll look into it. I have played a lot with the infinity controls already. I think my next best bet is to talk to carrier or contractor.

On a side note, the backup definitely comes on during defrost mode but that is it since you can manually lock it out if the outside temp is above X degrees.

Thanks for the follow ups!


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Why would one want to lock out or deactivate backup heat strips unless you just enjoy AC in the middle of the winter?

Backup strip heat is supposed to operate on defrost calls.

Keep in mind location is Massachusetts.

IMO


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Hello Tigerdunes, the heat strip uses a lot more energy compared to the heat pump. My heat loss in my house is minimal (I had it sealed last year). My thought is since my house won't really drop much temp during defrost mode why spend the extra energy on the heat strip when the heat pump can catch up pretty easily when the defrost mode was done. After some reading it is my understanding that the defrost mode is basically AC mode to create heat around the coils and melt the frost. Didn't see anything about the secondary heat source being used as the defroster. I am by no means an expert and could be wrong..... Thanks for your input.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

The aux heat from the heat strip on defrost calls is to temper the AC air coming into your home. If you like AC with outside temps below freezing, then it suits the heck out of me. Poor strategy for comfort though.

IMO


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Alternatively the system could shut down the fan while the defrost mode is on so cold/ac air isn't being sent throughout the house. This would prevent the need to have the secondary heat source heat cold air coming in. Is this possible? Just brain storming... :)


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Hi all!
Any update on the Greenspeed energy usage and how well the Greenspeed works in cold cold (say in the teens) weather in Massachusetts? Have been thinking about installing it as the sole heating source for my house (about 2700 sq. feet on two floors without counting the finished basement [baseboard heat in basement]). Currently I have oil and have all working ductwork. The house was built in 1999 and has had Mass Saves energy audit. The house had air sealing done and additional ceiling insulation added to the current code. The house airflow is about ½ the Mass Save recommended requirement, so it is very air tight. I am able to heat my first floor with two 1500W space heaters and should be able to do the same for my second floor. By my calculation, it would take a heat pump with a minimum of 10,236 BTU/H to heat one floor of my house and 20,472 BTU/H to heat both of my floors (3KWH X 3412 BTU/KWH X 2 floors). Not sure if this is a good way to estimate how much heat I need per hour for my house. Anyway, before anyone says anything electrical heating, I would like to say that I do have solar panels and the panels are giving me a lot of excess KWH and this is why I am using portable heaters to heat my house in order to reduce using my oil heat. Anyway, any advice or update would be much appreciated.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Hello stleebike, I posted data on summer usage above. The only cold weather usage I have experienced was October this year which I used 186 kWh which = roughly $28 (Oct 13th and forward it was a constant 40s to mid 30s at night). I keep my house at 65 when we sleep and 68 when we are there. It's an all electric system. I have two zones and 2300 sq feet. Sealed and insulated. Single pane windows with storms.

Very clean and no more smells of oil... Very quiet operation as well.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Sabs: Sounds like the HP is working out for you. I think I have the Bryant equivalent of your system which is the Bryant Evolutions Extreme. I cannot figure out how to enter the kwh costs into the controller to gauge costs (may not have this on the Evolution) but was wondering if you could tell me the steps you take to get to that screen? Thanks


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Sabs said "Alternatively the system could shut down the fan while the defrost mode is on so cold/ac air isn't being sent throughout the house...."

During defrost operations, inside the home the unit must remove heat from the inside ambient (requiring inside fan operation) and send it to the outside unit... the outside unit will have it's fan off to prevent sending that heat to the outside ambient but rather use that heat to melt the ice off the coil.

This post was edited by saltidawg on Sat, Nov 16, 13 at 11:20


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Auggie, I have the infinity control thermostat which I understand is only a carrier product. I wouldn't be able to help with your system as I am not familiar with your thermostat/control. Sorry.

Saltidawg, sounds like the heat strip has to stay on during defrost. Thanks for info.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

"sounds like the heat strip has to stay on during defrost. Thanks for info."

I have oil as my backup heat... in my case, the oil furnace is lit off and adding heat as the Heat Pump tries to cool the house down and send the heat outside to defrost.

It seems that the amount of oil consumed during defrost is miniscule, however there seems to be a huge focus (here) on the wastefulness of timed defrosts.

I'll have to look at that sometime.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Moved to new thread

This post was edited by kwwny on Sun, Nov 24, 13 at 13:24


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

kwwny,

Welcome to the forum. It is not polite to hijack someone else's topic thread. I suggest you start you start your own. You will get better responses.

If you don't have the installation manual for your thermostat then let me know. I will post a link where you can find it. It will help answer some of your questions.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Hi All. Live in eastern Ontario and just got installed a Greenspeed 25VNA048 heat pump w a 59MN7080 gas furnace to stop paying for oil.
It was a learning curve for this system as it is an advanced heat pump system - expect the competition to ramp up their pumps HSPF to 13 also or lose the market.
My coldest night so far was -15C and we got our 21C/70F indoor temp in our 2800 sq.ft house.My balance point is set for -17C/1F and I should be getting to -18C this wed/Thurs evening for a real test for the normal switch to gas furnace.
Yes the system by default uses gas heat on defrost. Without it it would be blasting cold air in the ducts for 5 minutes. So the gas frnace heat modulates at 65% so to neutralize the cold air so air temp swings are minimum for comfort.
Yes you can disable this on the touch screen interface in service/ setup/ heat source lockouts.
Yes one can monitor electrical costs in $$$ or Kw and gas $$$ or therms on a per day/ per month and per year to date on the interface.
I've experimented between the different options in choosing efficiency or comfort and there is a noticeable difference to the environment and a slight increase in costs of electricity between the two. I do prefer comfort.
On an average cold day 0C/32F w -5C at night it costs me @ $5 per day in electricity and with heat on defrost w/ continuous low fan for only an additional cost of $1 every third day (.33cents per day). (yes the different areas of kw usage is separated in the readout)
The only puzzle I have to resolve is last Saturday nite at 3 am the house felt cold - it was 15 F outside. Gas furnace came on for a couple of hours before pump came back ???. No codes or resetable fault codes registered on interface. The only way for the gas to go on at that temp way above the balance point is a 2 degree drop or a manual increase of temp of 2 degrees or more. So why did did happen.... stay tuned....
Gotta love saving money. Last year in October it cost me $425 in oil - this year for Oct gas+electrical $202
Included is a pic
Update Jan 2014: had issues w furnace overiding heatpump prematurely and Carrier change my thermostat which had Version 9 to version 10 software - issue fixed.
those who want to see what savings a heat pump can have over your specific system try this:
http://sagoro.wrightsoft.com/Carrier/Default.aspx

This post was edited by Cocobob on Mon, Jan 13, 14 at 23:22


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

Please refer to my post about service settings I saw energy usage of 38 kwh during highs in the teens and a low of 0 degrees outside temp with 73 inside set point. No setbacks.


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RE: Carrier Greenspeed 25VNA Heat Pump Electricity Usage in Cold

How did you make out in Massachusetts over December-March? How many kwH did you use in the polar vortex? does that include your heat strip?


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