Lessons learned from Winter 2010...

[AC_Hacker]

Seems to me that it would be a good idea to have a centralized place on Ecorenovator to post what we have learned from our actual efforts.

I'm a believer that we can learn from our successes and also from our failures. In fact our failures might be able to teach us more than our successes, because there will probably be more of them.

As for myself, my efforts have been proceeding in two overall directions:

• Energy Efficiency
• Energy Use Reduction

Energy Efficiency:

• TANKLESS DEMAND WATER HEATER
  I installed this about fifteen years ago, and it has saved me lots of energy and money ever since. Tankless heaters do NOT offer warm water as quickly as tank-type heaters do... it comes with the territory. I installed my tankless next to the old water heater, as it was easiest to plumb in. That turned out to NOT be the most energy-efficient strategy. Since the heater is so small, it can be installed as close as possible to the point of MOST FREQUENT use. I have seen very small inexpensive tankless heaters on ebay that could each be installed near each point of use. Most of these use propane, but could be re-jetted to natural gas if required.
  I have also seen much higher efficiency condensing, modulating tankless heaters. If one required high volume use of hot water (hydronic heating and/or high occupancy use) this would be easuly advantagous. Whether this would provide better value/efficiency for my modest use, would call for very careful analysis, particularly if such a water heater was used as a backup for the GSHP project.
• HYBRID CAR
  (I actually got this car a few years ago, and haven't mentioned it before, but it has proved to be such a boon to my energy reduction that I thought it needs mentioning.)
  I bought a used 2000 Honda Insight off of ebay for $7000. My lowest mileage has been 47 mpg and my highest has been 88.2 mpg. I usually expect mileage in the low 60's for around-town driving in the summer, and in the winter when the batteries are cold and don't work as well, I expect around-town mileage in the low 50's. Careful freeway driving seems to be about 15% to 20% better, summer & winter.
  Since the engine is so small, the AC really reduces the mpg... ditto headlights & radio to some extent.
  Proper tire inflation is critical and needs to be carefully monitored.
  One of the most useful aspects of the car has been the real-time mileage gauge. In my opinion, every new car should come with one.
• MAJOR HOUSE INSULATION UPGRADE
  This is an on-going project that has been in process on for over twenty years, and has changed in the direction toward greater efficiency, several times. I started with minimum R-Value fiberglass wall fill. Since my house was built in the early 1890's, and had zero insulation when I bought it, this certainly improved both the thermal performance and quietness of the house.
  Over time, as global energy realities and my knowledge have changed, I have very much changed my approach, and am now tearing off the old inside walls, adding an extra two inches to their thickness, and filling the roof and wall cavities with sealed layers of solid EPS foam. I began with the entire roof segment of the house. The amount of work required to do this is very high, but the thermal insulation is also very high. I have learned that the effects of these changes become more pronounced as each room approaches completion... before that it seems that the work was done in vain. This winter, my son & I worked on insulating the kitchen and have completed two of three exterior walls. The first wall made no difference. The second wall made no difference until it was approaching completion, then I noticed that on all but the coldest days, I could keep the kitchen comfortable by using the kitchen oven on 'warm'. Previously, this was not possible. I still have one exterior wall and the floor to go. I think it is reasonable to expect that after completion, the oven pilot light alone should be enough to keep the kitchen comfortable.
  I have also learned that as rooms get radically tighter, room ventilation becomes a requirement instead of an option, and unless an energy recovery system is used in this regard, large amounts of efficiencies formerly gained, will be lost.
  Energy recovery and heat recovery ventilators are available, but I have not found many options for small-space ventilation. I'm keeping a keen eye on developments on this thread, the only DIY ERV thread I am aware of...
  
• RICE COOKER ECO_HACK
  This has been a success, as the ideas that I tried out actually worked, and in working with the cooking process, I learned to understand better how the cooking process actually works, which in turn allowed even greater efficiency. The actual energy saved was very small(pennies per use), but the insights gained are valuable.
• DIY GROUND SOURCE HEAT PUMP
  This is a monster project and not yet in operation, so I can't yet comment on performance, but the strategy of re-purposing tools (Shop-Vac for earth removal, heating element from mini-panini maker used for heating element of plastic pipe welder, etc.) has been a complete success. Thrift stores have been at least as valuable to me in this project as hardware stores.
  Digging a loop-field by hand is unquestionably a very difficult proposition, and should only be attempted by youth and/or lots of mechanical power.
• MINI-SPLIT INSTALLATION
  I didn't document my mini-split installation, but I did contribute information to a mini-split installation on this blog that is well documented. I installed my unit as a temporary expedient while my GSHP project proceeds. My experiences with my mini-split have been very, very positive. My electricity bill is now not much higher than it was before the mini-split, and my gas bill (I previously used gas forced air) has dropped to the point that some months the charge to read the meter is higher that the charge for the gas used.
  Also, the comfort of the mini-split is much better than my old gas forced air furnace, which became progressively more intolerable as I reduced the heated area of my house.

Energy Use Reduction:

• DRIVE LESS
  It is very useful to compare the overall domestic energy use with the energy use of a car. I did and it has change my car and my driving habits.
• SET-BACK THERMOSTAT
  I put one of these on my old gas furnace. It helped immediately to reduce my gas bills. My mini-split has one also. Very good
• ENERGY EFFICIENT LIGHTING
  I now have almost no incandescent lighting in the house, with the exception of task lighting, like on my machine tools (where I consider it to be a safety feature), and as a reading light. I have also been experimenting with reducing the level of area lighting and am pleased with the results. It's not so easy to find really low wattage CFL lights (< 6 watts). I have found a few and I like the look & feel. I tried LED lighting and was not pleased with the blue cast of the light, but am very pleased with the color of the newer generation of LEDs. I have a couple high-tech LED task lights that I really like, but their price is discouraging me from full implementation.
• REDUCE HEATED AREA OF THE HOUSE
  This has been the cheapest, fastest, and most effective strategy I have employed.
  I now just heat the room I am in. I tried this with the old gas forced air furnace, and the result were not pleasant. I then tried only resistance heating. More pleasant, until I got my electric bill.
  Because the furnace air-circulating motor had only one speed, the furnace was forcing all the air it formerly sent through the whole house, through the room I was sitting in. The result was that I felt like I was wintering in a convection oven. In fact I was.
  The mini-split has a continuously-modulating circulating motor, and can dial down the air as needed. Much, much better. I do wonder that if I had gotten a mini-split that was sized to heat the whole house, would it have been as comfortable when heating just one room? I don't know the answer...
  However, during this last winter, we had a serious (for Portland) cold snap with temperatures plunging down to 12 degrees F to 17 degrees F for about a week. During that time, my mini-split energy consumption was about $6.50 (six dollars and fifty cents) per week. No resistance heating was required.
  On lesson learned this winter is that when energy use is radically reduced, special attention needs to be given to water pipes, as some of my "wasted energy" was actually keeping my pipes from freezing. During the cold snap I did suffer frozen pipes (feed line to the toilet and drain line from the bath). I think this can be managed with careful pipe placement (place pipes in or adjacent to heated areas) and with insulation and local warming of pipes. I think that a 100 watt light bulb with a freeze-activated switch would take care of the situation.
  
  

[Xringer]

Good post.. I noticed you wrote mini-split about 10 times.

"I do wonder that if I had gotten a mini-split that was sized to heat the whole house,
would it have been as comfortable when heating just one room? I don't know the answer..."

I think your comfort level in rooms that are farther away from a centrally
located mini-split, is going to depend on how tight those rooms are
and the amount of air flow into those rooms. (from the main room).

In our house, warm air flows into other rooms, mostly on the ceiling.
Cold air comes from the cooler rooms, traveling along the floor.
It's pretty easy to assist the cold air out of a room using a small
fan, placed on the floor of the cold room, just inside the doorway.
Cold air coming out on the floor, means the room is going to slowly
warm up, from the ceiling down.
I made sure that my attic installation was as good as I could make it, within reason.
Low (8 foot) ceilings helps too.. Not so much over-head to heat..

Notice the old wood stove in the fireplace.

Back in the old days, when that stove was used for heat a few times,
it put out a LOT of heat and warmed right down the hall into the bed rooms.
It has a wrap-around steel jacket with a blower in the back, and it really kicks out the BTUs..



So, I knew that a single source of warm air would work, about 30 years
before I decided to try a mini-split..

The Sanyo is perfectly aligned. It can shoot right down the hall. We just adjust the
Sanyo output a little high and point the vent down the hall,
and those rooms warm up nicely.

If it's 68 down the hall and we want it up to 70, we just turn the heat
in the living room up to 72.(or 74 for a faster change).



My guess is, if you had purchased enough BTUs in that mini-split,
you would have a lot less motivation to complete the GSHP!

I can't imagine a GSHP installed in my house that could draw much less wattage
than the energy used by my Sanyo even by 30%..
(Unless it was a deluxe GSHP that has the same technology as my Sanyo).

These things so effective and efficient, there is no way I would ever
even think about digging up my backyard to install a GSHP..

And then of course there's all the big rocks buried in the back yard!!

Cheers,
Rich

[AC_Hacker]

Originally Posted by Xringer

I can't imagine a GSHP installed in my house that could draw much less wattage than the energy used by my Sanyo even by 30%.

I know you're happy with your mini-split, I'm enjoying mine too.

Here's a chart from a study of 200 homes done at Fort Polk, when they switched from ASHP to GSHP.

Full study can be found here.


-AC_Hacker