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Changing from thermal storage unit to NG, advice please.

Posted by ghostdog1108 (My Page) on
Sun, Jul 10, 11 at 22:23

My wife and I live in a ranch home in central Wisconsin.
Home was built in 1979 with 1310 sq ft up and 950 sq ft finished in a walkout lower level.
Duct work will need to be installed. Looking at the Lennox
SLP 98 with AC. Any advice on proceeding with this endeavor
will be appreciated.


Follow-Up Postings:

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RE: Changing from thermal storage unit to NG, advice please.

I would suggest looking into a Carrier Infinity Greenspeed heat pump system. This way you may not need NG & would have heating & cooling at every high efficiency. You would have to compare relative energy costs however with some future energy predictions.

SR

Here is a link that might be useful: Carrier Greenspeed


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RE: Changing from thermal storage unit to NG, advice please.

Temperatures during the winter months drop to -25 degrees or more. (Zone 4)
Are heat pumps a good choich for these winter conditions?


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RE: Changing from thermal storage unit to NG, advice please.

According to the chart, the balance point for a Carrier Greenspeed HP is about
-14 degrees F for a 3-ton unit.

It should work fine in your region.

SR


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RE: Changing from thermal storage unit to NG, advice please.

"According to the chart, the balance point for a Carrier Greenspeed HP is about -14 degrees F for a 3-ton unit."

I looked at the chart and don't see how you came to conclusion. Can you explain what you mean by this statement?


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RE: Changing from thermal storage unit to NG, advice please.

Re: mike home

I apologize, I checked the chart again, I am in error. That should have been
-14 degrees C, according to this chart.

SR


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RE: Changing from thermal storage unit to NG, advice please.

I am ignorant when it comes to heat pumps, so perhaps you can educate me.

The chart in the 25VNA Product Data shows at -14C degrees the heating capacity to be about 18,000 BTU. How do you determine the balance point for the OP's house with this information?


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RE: Changing from thermal storage unit to NG, advice please.

Re: mike home

I never suggested I knew what the balance point was for the OP’s home. The chart I was referring to states that the balance point for a 3-ton 25VNA (Greenspeed) HP is
-14 degrees Celsius with an output of about 22MBtu at that temperature and a 21.1 degree C EAT. It was part of a presentation prepared by Carrier Canada for dealers in Quebec. Perhaps I should have mentioned that.

It’s basically the same info as found on page 11 of the Carrier 25VNA Product Data pdf. However, as someone feigning ignorance you would likely already have known that.

SR

Here is a link that might be useful: Carrier Greenspeed 25VNA Product Data pdf


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RE: Changing from thermal storage unit to NG, advice please.

The part I don't understand how the chart determines the balance point for a given temperature. It does not make sense to me.


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RE: Changing from thermal storage unit to NG, advice please.

Re: mike home

I think what you’re saying is these charts are not footnoted and referenced to a city with a specific design temperature as well as Manual J calcs for a specific envelope. This is something that would have to be taken up with the Carrier Corporation.

The charts do say:

BUILDING HEAT LOSS, UNIT INTEGRATED HEATING CAPACITY, MBTUH Vs OUTDOOR TEMPERATURE F(C)

The presentation prepared by Carrier Canada for dealers in the Quebec region does however mention balance point for a 3 ton 25VNA system in a 3,000sq ft cottage along with all the BIN data for Montreal including total heating hours and cooling hours. I would like to post this presentation but won’t for 2 reasons. First is that I don’t own the material and second is that it’s entirely in French.

Regarding the 25VNA product data pdf, there are 2 notes, one on page 1 and the other on page 27 that state:

Ratings contained in this document are subject to change at any time. Always refer to the AHRI directory (www.ahridirectory.org) for the most up-to-date ratings information.

The testing of these units is probably referenced to AHRI norms and protocols. Check the AHRI site.

SR

Here is a link that might be useful: AHRI


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