What is your average kWh/day usage?

[stefanc]

The issue is that I need 1 in each bedroom (3x 9kbtus) and two downstairs (2-12k btus).

I don't think that's unreasonable, I really need to be able to control each bedroom as I have two small children. And my first floor would benefit from having two because of the configuration. Ill start a new thread when I get a chance to discuss.

Thanks!

[Gerhardt]

my wife and I live in a 1900sf house. Nat gas for heat cooking, and hot water, electric for everything else. Two years ago our daily electric uses was 16.8 per day, this year we are down to 11.9 with a goal of 10 next year.
All cfl lighting, upgraded to a 95% efficient furnace and a 13seer A/C. We got rid of our 20 yr old freezer and a mini fridge of about the same age. Most laundy is air dried as running the dryer 3x on laundry day added at least 6kwh per day. I have resealed all windows and doors and insulated the attic access door and the louvers on the whole house fan. TV and computers are on power strips which are switched off and we make sure to unplug wall-warts(charger/adapters) when not in use.
I added a 4.17 PV array this past summer. My average generation has been 13.61 per day and for the first 5 months of operation I have achieved a net zero in electricity.
Next project is my attack on natural gas which is 22.7 therms per month.

[AC_Hacker]

Originally Posted by Gerhardt

Next project is my attack on natural gas which is 22.7 therms per month.

Looks like you have made great strides in your electricity reduction, congratulations.

So your gas consumption of 22.7 therms comes to 2,270,000 BTU/month, not a very useful number, except for billing.

It also comes to 3153 BTU/hour, which would be a useful number if it was your peak usage month, like December, January or February, because it would give a clue as to your heat loss.

Actually, if you had some way of measuring the ON-time of your gas furnace during various days, and if you recorded the outside temperatures during those times, you could determine precisely what your heat loss is, as it relates to your outdoor temperatures.

I have seen AC hour-counting meters that you could connect in parallel with your furnace blower-motor, and that would do it just dandy. For the above meter you'd need a step-down transformer to get the right voltage.

That would be very useful information for your energy-reduction project.

A blower door test would be very useful for you, as you would then know how much infiltration you still need to eliminate.

Then comes the insulation part... probably want to wait until after you have done the other steps before you tackle insulation.

You may also want to take a really hard look at reducing the heated area of your house. I have done this and the results are astounding. I have gotten my heat bill down to around $20 to $30 per month. I do live in Portland, Oregon which is less cold than where you live, but even so, My whole house bills were formerly around $80 to $100 per month at this time of year. When I started implementing my area-reduction strategy, I ran into problems, since the furnace I was using used a single-speed blower, and when I had radically reduced the heated area, the blower was dreadfully over-sized for the new heating needs, and it was not so comfortable... very rapid heat rises, short-cycling, etc.

I have also embarked on a radical insulation project which involves tearing out all of the sheet rock in the exterior walls and exterior ceilings, increasing the wall thickness 50%, and filling the walls with three sealed layers of rigid foam insulation board. The insulation project does not yet include the part of the house that I am actually heating, but the heat-retention in those newly-insulated areas has improved greatly, to the point that in most cases, there is enough heat leaking into the unheated rooms for them to be chilly but not really cold. Right now for instance, it is 36F outside, 68F in the heated area, and 50F in the 'unheated' rooms.

Another technique I am currently using is an Air Source Heat Pump (AKA: ASHP). This little ruby is electric, puts out 12,000 BTU/hr max (it never runs to the max), and gives me around 2.5 times the energy in heat as I put into it as electricity. It is just amazing. It also gives me good AC for the week or so per year that I need it here.

My larger project is a very small Ground Source Heat Pump I am building.

Good luck with your continuing energy reduction project(s)!

Lots of support and ideas here at EcoRenovator...

-AC_Hacker

[MN Renovator]

"When I started implementing my area-reduction strategy, I ran into problems, since the furnace I was using used a single-speed blower, and when I had radically reduced the heated area, the blower was dreadfully over-sized for the new heating needs, and it was not so comfortable... very rapid heat rises, short-cycling, etc."

No, the blower wasn't oversized for the new heating needs, the furnace is. Lowering the blower speed or shrinking the blower only reduces air flow which is what will increase your temperature rise. Depending on how much air flow is actually passing over the heat exchanger since your duct work is severely restricting it since the ductwork designed for your reduced area is very likely undersized, you likely went overspec on the temperature rise which puts you at an extreme risk of cracking the heat exchanger which puts you at risk for carbon monoxide issues that are directly solely to the reduced area of the house you are sleeping in. Be very careful with changing how much air passes through a furnace. If using a furnace you need to allow the right amount of air to pass through, or use a smaller furnace, mini-split, wall heater, etc. ..or in your case you've got your mini-ground source heat pump to play with. I like the idea of your DIY ground source and I might try to do something similar eventually if I can get my hands on a small enough setup to play with to allow me to use a tiny drilled ground loop setup.

I don't think the hour-meter you posted is capable of dealing with counting hours for a furnace unless you tied it into a low-voltage thermostat, its only rated 0-60v ac/dc

[AC_Hacker]

Originally Posted by MN Renovator

I don't think the hour-meter you posted is capable of dealing with counting hours for a furnace unless you tied it into a low-voltage thermostat, its only rated 0-60v ac/dc

My thought was to use a 120 to 24 volt step-down transformer with the 120v end connected in parallel to the blower motor, and the 12v end connected to the meter.

[Gerhardt]

Here are the past 12 months of gas usage

#days HDD therms
01/02/11 31 1160 73.7
01/31/11 29 1078 67.5
03/02/11 30 834 58
03/31/11 29 512 37.9
05/02/11 32 193 13.3
06/01/11 30 102 7.1
06/30/11 29 5.1
08/01/11 32 5.1
09/01/11 29 3.0
09/29/11 30 55 5.1
11/01/11 28 126 11.1
12/01/11 33 445 34
Total 4505 HDD 320.9 therms (down from 461 with the previous furnace)
The heat pump idea is not practicle in this are due to the number of below 32' days and the furnace is 1 yr old and replacement is not cost effective.
The exterior walls are 6" SIP (structural insulation panels) and the water heater is an instant gas model.
I have the materials to seal the exposed ducts so that should help and some rooms are now closed. The most significant energy theif is a pair of dbl pane 2x4 skylights. I guess I will investigate some sort of movable insulation for them.

[Xringer]

"The heat pump idea is not practical in this are due to the number of below 32' days"??

Or, maybe not.. Guess which one of these charts is for St. Louis, Missouri
and which one is for Woburn Ma..

St. Louis looks like the idea location for running a Mini-split ASHP..

I did a rough study of the 60 coldest days of the winter in Woburn Ma,
by looking up at some old local records, and I think the average temperature around here, is well above 25F..

We just a long 25 deg F period, (about 15 hours. See pic..)
During that that time span, my two Sanyo Mini-split 24k ASHPs
were using about 1.1 kW per hour (total). (Keeping us at 69-70F).

Wednesday night when it dropped down to about 8.5F around here, (see URL)
Climatological Data
our Sanyos were using more power (for a while), but we were still toasty..

So, we've been having pretty close to worse-case weather and staying
real warm, for less than 4 to 5 bucks a day. So, they do work..

The only problem I see, is you have a higher dew point then we have around here. Meaning your system will run more defrost cycles.

During the spring and summer, the dehumidify mode on these Sanyos is dynamite. The cooling mode is fantastic.

Edit:
I just looked at
http://www.wunderground.com/weathers...p?ID=KMOPACIF5
and I'm wondering, is it really 68.7 °F at Lake Cattails, Pacific, MO on 1/5/2012??
Because, that's warmer than where I'm sitting right now..
If you live around there, you don't need much heat today!! LOL!

[PaleMelanesian]

Woot! New record low for December! This new heat pump is really working. It's only gone into defrost mode a handful of times, where the old one would have given up by now, requiring the backup heating coils.

1887 kWh for the month, beating my 5-year average of 3224 kWh.

Our December temperatures here in Texas were nearly identical to last year's. It felt warmer, but the numbers don't show that. This year was more steady and cool where last year was more bipolar, hotter and colder. (based on degreedays.net and national weather service)

[Daox]

Wow, not too far from half the consumption. I'd say thats a big win!

[PaleMelanesian]

Having the better heat pump that can work down to the minimum temperatures we have makes all the difference. I'm actually surprised at how good this is. My preview calculations were based on the direct SEER difference, without considering the lack of backup heat.