Propane Vs. Solar

[lliefveld]

To answer your other questions, yes, we do have a well, the well is 420 feet, but the water level is at 120 feet. We've factored in the cost to run the well.

We plan on 'regular' Energy Star rated appliances (not the ones that run on just solar, at 12-volt, or the ones that are super-duper insulated).

Our nearest neighbor has 3 trackers, and a 12-battery array. Their house is 4000 sq ft, and is rammed earth construction. They have normal applicances, two computers, a wine cellar, a swamp cooler, a large-screen TV.... in other words, all the comforts. Their system cost $65K 3 years ago. We've talked with the designer of their system, and he indicated that they went way above what was necessary and that they have a premium system. During the summer, their battery array is full by 10am, and in the winter, the backup generator runs about an hour a day.

Our house will be smaller (about 3000 sq ft), but a more normal construction. But we'll have a 10 ft covered deck, so the sun doesn't heat up the house in the summer, and a basement under the living room. We're planning on radiant heat under the floors for the couple of months in the winter that we need it.

I guess one factor that I should mention is that we're in Central California, which is a mild climate. Summers have a week of really hot (100 degree) weather, but other than that, it's not usually hotter than the low 90's, and it's dry. We have a great breeze. The winters are mild - it's snowed once in the last 75 years. We have an occasional frost during the coldest months.

We expect we'll run the heater for maybe 2 months out of the year, and only for a few hours. Same thing for whatever cooling we use.

[Pat]

lliefveld, Luckily the statue of limitations has run its course on my degrees and they can't take them back now.... DU__UHHH

Of course you have the budget to leverage against with that sort of installation cost. Being in swamp cooler territory is a good thing as the latent heat load is expensive to ameliorate.

We have a rooftop swamp cooler on our pickup camper in addition to the rooftop mechanical refrigeration unit. It only takes 5-6 amps to run it depending on Lo vs Hi speed. Our 12Volt solar installaltion on the camper develops about 12 amps (most I've seen from it is 14) so there is plenty to run the cooler and whatever else is needed. I started to design a one or two axis tilt mount but decided to just take what I get mounting them flat on the roof. So much easier, no climbing up to tilt, securing for the road, etc and we get plenty of power.

Super insulation and a whole house fan to bring in the cool night air will sure reduce your A/C needs and the insulation will make it dead simple to heat too. In your climate situation if you don't get too carried away with fenestration there probably wouldn't be a reasonable payback for triple glazed windows over double with low e and maybe argon fill.

Rammed earth is a great idea in your area. Concrete does the same thermal job but costs a lot more. The huge thermal flywheel effect of the rammed earth generates quite a phase shift between the thermal input and the resultant temps.

I'm still getting used to our various hydronically heated zones, some in-ceiling, some floor slab, and walls and floor in the shower. The ceilings have a decent resonse time but the great room floor is pretty slow. I haven't computed the thermal time constant yet but it is pretty long. Given our variable temps; 8f one morning, 2F another then 30F with 60F+ in the evening... wow.

Luckily I can get warm forced air from the A/C ducts along with the warm water in the floor. I'm learning where to set the thermostat that controls the water and how much to offset the forced air stat for a good composite result. This prevents excess heat storage in the floor and overheating in the afternoon if it warms up. Colder weather with less wild variations and we wouldn't need any supplemental warm air.

The record delta T in a 24 hour period is in excess of 80F.

We moved here after decades in San Diego which is about as perfect a climate as I have ever experienced, so much so as to be boring.

Sounds like you have it UNDER CONTROL and should have a very comfortable experience.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[lliefveld]

thanks, Pat for thinking we have it under control.... we feel very out of control, actually.<g>

You mentioned a whole house attic fan and we are talking about those. There are several different types, and we're looking at them all. My husband installed a couple of turbine type attic fans in the last house, and it made a HUGE difference!

And we are looking at the double low-e windows, not the triple...but probably argon filled.

As for the rammed earth construction, I think it makes a huge difference in the evenness of the temperature in the house, and I kind of like the looks of it - sort of a modern-day adobe. But my husband hates it, so we'll just have lots of insulation (and Hardie siding for the fire-resistence, since we're in wildfire territory).

We currently live in Southern California, too (Rancho Cucamonga), and are building in Central California. Fortunately, Three Rivers has very close to the same weather as Rancho, so it won't be as much of an adjustment.

I can't even imagine a delta of 80F in 24 hours!

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] Dear Veld: I'm sure that you are aware that the climate in the Three Rivers area mimics the climate in most of the orange-growing areas that are close by, and as such you'll need a bundle of air conditioning. We fled CA almost five years ago, but had we stuck around, I definitely would have constructed a time-of-day thermal bank to combat the summer heat and the on-peak power penalties. There are several facilities in CA who use "ice packs" as thermal storage, and also tanks of that special fluid that Eutectic makes that is something like 2.2 times the heat capacity of water. These folks cool that BIG vat of water to a chilly temp using the cold night air to cool their condensors and then run all day with only a fan coil and a small circulator, no compressor. If it wuz me, I would be looking to do something serious about the air conditioning side of the thermal equation. [img]/forums/images/icons/tongue.gif[/img]

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] Pat, I'm taking exception to your use of the term "SWAMP" when referring to that wonderful and efficient climate modifier known as an evaporative cooler. "Evaporative" has an almost-medical sound to it whereas "swamp" conjures up a vision of mosquitoes, scum-covered brackish water, snakes, quicksand, and beri beri. [img]/forums/images/icons/wink.gif[/img]

[lliefveld]

Hi CJ - yep, it does get very warm. It actually comes pretty close to the same temps that we experience in Rancho Cucamonga, where we currently live. And we used our air conditioner about 2 weeks this year, during the 102-105 degree weather. We open all windows in the late afternoon, catch the breeze, and the house cools off to about 75. Close all the windows in the morning, and it stays reasonable until about 3pm, when we start the process all over again.

We've actually been camping on our property for a over a year and a half now, and I'll tell you, 105 degree weather is really bad when you're camping (unless you can sit in a lake or river).

Our home site is up on an outcropping, and it catches a very good breeze almost all the time during the summer. We'll also have a basement, and a patio that is underneath the master bedroom. Both of those 'should' be cooler than the house.

The current plans do call for an air conditioner, but since we're off-grid and we may only use it for a very brief time, we're debating whether the cost is worth it. Once we get the bids back, we'll see if it's something we think we need to cut, financially.

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] The "off grid" aspect of the "Veld" project would seem to lend itself nicely to the thermal storage concept since you can cool the liquid in the storage tank at night with a very small refrigeration system running over several hours, thus reducing the connected wattage requirement for a conventional air conditioner. Otherwise there is just no avoiding having to run a high-input compressor for those peak hours so you don't fry. [img]/forums/images/icons/tongue.gif[/img] Since moving to the Midwest, I have had to sort of modify my thinking about air conditioning since our requirement here is straining the moisture out of the air more than battling high temperature. We have very few days of over 100 degrees, but many days with 85% humidity. So.....what we use is a small unit, with only enough freon in it to where it "makes water" and then we run it almost continuously to keep things dry. We have to go from 95 degrees down to 70, not 110 to 70. [img]/forums/images/icons/tongue.gif[/img]

[Pat]

Hey Dave, I didn't invent the "S" word and I think it refers to the smell which many emit.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[lliefveld]

Thanks, Dave..... We'll look into that.

[Pat]

lliefveld, If your relative humidity is low enough evaporative cooling is a good idea. There are also some other variants on evap and other innovative cooling methods. Ever hear of cool tubes? Basically tubes burried deep through which air passes and is cooled on the way to the house. Only power for a fan is required and that can be eliliminated with some designs. There are arrangements for elliminating the fan most or all of the time. Some of the early applications of cool tubes failed to be useful as they were done by amatures and ended up as breeding grounds for fungi but there are ways to handle that so it is a non problem.

There are cooling tower applications that can be blended into many architectural styles. THese provide good evaporative cooling with no requirement for a fan. A good installation creates a decent breeze on its own.

I did a lot of research on various alternative systems of building, air conditioning, and so forth before I picked the northern end of south scentral Oklahoma as homesite target. I can't do squat with evap cooling here but have done plenty with it previously.

If any of these innovative cooling concepts interest you, let me know and I willl elaborate.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]