Did you have a warm Nov & Dec 2011?

[Xringer]

We've used 3.5 kWh (for heating) during the last 8.2 hours..
Maybe I shouldn't try to forecast when it's going to get cold..
The last 30 days has been 42.7 °F on average.. (35.4 °F in 2010).


If the 'Professionals' can't get it right, I'm going to have to 'withdraw' my forecast..
(I'm forecasting the average will sink down below freezing at some point this year. )
Since it's possible the winter is going to set-in during the first part of 2012..
Hurricane experts admit they can

[strider3700]

Do you have a thread describing your house Xringer? quick math suggests you're using 14kwh a day to heat and your temps are swinging not too far away from where we are at the moment yet my Heatpump uses 20kwh a day. I'm just wondering if minisplits are that much more efficient or if it's a size/insulation level thing.

[Xringer]

It's a small 3BR 1956 ranch, with an add-on den (that's hard to heat)
and we are heating almost the whole house. (abt 1200 sq ft)
The smallest bedroom is un-used about 70% of the time.
Which means we keep the door closed a lot. It does get chilly in there.

The attic insulation isn't what most would call great, but it's way better
than most on this street. The wall insulation is poor, but we did leave
the old wooden shingles on (w/ a 1/2" fiber padding underneath),
when we added the vinyl siding (w/ 1/2" foam insulation underneath).
The windows are double pane replacement type, medium quality
and the doors leak cold air.. They need work..

My guess is, the insulation would be pretty good, if this house was in VA or NC..





IMHO, These two Sanyos are very efficient, and work well in a house this size..

The published heating spec says during a day like today, one of these
24k BTUh units could put out 36k BTUh. That's 72k BTUh (of heat) total.
But, these things rarely run more than a few minutes at high power.
They just peak (3kw /w both at max) when the setpoint is increased,
then they mellow out running about 900w (450w each).

[AC_Hacker]

Originally Posted by strider3700

I'm just wondering if minisplits are that much more efficient or if it's a size/insulation level thing.

Yes, mini-splits really are that much more efficient.

They were pretty much developed in Asia, where cheap energy is not abundant, but technical talent is.

The technical improvements in mini-splits, most notably variable speed compressors (AKA: Inverter Technology) are not yet available in whole house systems, although sales literature that describes it is available.

If you might be investigating the mini-split option, be advised that most sales people are fixated on SEER, which is an index that mostly applies to the heat pump's cooling efficiency.

FYI, the specification you would want to focus on is HSPF, which stands for Heating Season Performance Factor. If you divide this by 3.412, you will get the heating season average COP. This will let you compare whole house heat pump efficiency with mini-split heat pumps.

-AC_Hacker

[strider3700]

it's hard to say in this case. My house is twice the size of his yet I'm only using 30% more energy to heat it with my big old heatpump. we'd need to do far more detailed analysis since we're both using averages on temps and so on but I won't be replacing my central heating for multiple mini splits any time soon. The financial payback is very unlikely to be there for me.

[Xringer]

I agree.. It's like comparing apples and oranges.

But, that's how I do it! I compare Sanyos to Oil

Yesterday was pretty nice outdoors. We kept the heat at 21C and lowered to 20C while sleeping.

Daily Summary for December 16, 2011 at Climatological Data
shows the average outdoor was a cool 45.1 °F

During that 24 hour span, we used 9.9 kWh for heating. That's about $2.14

And the timer turned on the oil burner for 1/2 hour and burned about $2 in oil (need DHW).
However, if we left the Sanyos off, we would have burned at the least 10 or 15 bucks in oil..

I hope my retired neighbors don't read this. Yesterday, most of them burned around $20 for heat.
They might want to put me on trial for witchcraft!!

[Xringer]

The Sanyos used 20 kWh yesterday, 12/17/2011 (@ 32.7 °F average)
And today we are on track to use even more power!
So far, it's 10 kWh during the first 8 hours!!

Right now, it's 18.8°F and seems to be slowly dropping..
It should slowly come up, since the cloud cover is thinning out.


It was 21.3 F on average so far today..
Climatological Data

Maybe the sun will save us from using 24 kWh today (1kw per hour)!!

[Piwoslaw]

Here are the numbers for December in Warsaw:
avg max / avg mean / avg min / HDD (15.5°C)
+5 / +2 / 0 / 405 - 2011
-3 / -6 / -8 / 648 - 2010
+1 / -2 / -4 / 515 - 2009

Yes, we saw a third HDDs than in previous years!!
My road bike has never been outside between October and April, but the weather forecast suggests that I'll still be riding it in mid-January If it wasn't for the lack of precipitation I'd be regretting that our rain barrels are stowed away for the, ahem, "winter".

[NeilBlanchard]

HDD = heat degree days?

The ground doesn't stay frozen here more than a couple of days, and then it thaws for several days.

Lakes where we used to harvest ice (you know, for ice boxes!) several times a winter -- are just barely starting to freeze!

Motorcyclists are out riding on many different days.

It is way warmer than usual. Way warmer.

[Xringer]

Nov 1 to Jan 1 average temps Woburn MA.

2011 41.6 °F / 5.3 °C
2010 35.3 °F / 1.8 °C

Per the local data base at Climatological Data

It's still too cold for cranky old men, but I am enjoying the lack of back-pain..
(Due to the lack of snow)!

The forecast is for colder this coming week, but it's going to warm back up for the weekend..
Woburn Hourly Weather - AccuWeather Forecast for MA 01801

Tuesday is going to be pretty dang cold!


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Animation of North America Jet Stream Forecasts

The jet stream is going to loop south of new England and allow frosty Canadian air
to flow down a little 'valley' and smack us..