Alternative Power sources - Passive solar

Author

Passive solar - novice questions

bubbabubbs@yahoo.com

2005-12-20, 7:21 pm

We're in the market for a house (in the Denver metro area), and have
just been shown a passive solar house. We have absolutely no experience
with passive solar, but are by no means ruling it out. Actually, it
sounds pretty appealing considering the possible energy bill savings.

Case in point, the house we've been shown is a:

- 4-bedroom ranch facing south (great room, kitchen/breakfast nook,
master suite are along the long south-facing side),
- there's a little 3-ft-wide sun "room/compartment/buffer zone"
(not sure about the terminology here

'fronting' the great room;
it has floor-to-ceiling glass. Then, there are two _fairly small_
windows between that and the great room, plus a door that you can open
to let the warm air in from the sun room to the house.
- the other 3 bedrooms, 2 baths, and mud room are along the north and
west sides. No windows on the north side.
- the attached garage is by the east side of the house.

Pretty much a typical passive solar design.

I've done some reading about passive solar and one thing I've
learned is that how good a particular passive solar house is depends on
the quality of the design, quality of materials used, and maybe some
other things, too. But, being no expert, and w/o having to live in the
house for a full year, how do I decide how energy efficient the house
is?

Some other questions/concerns:
- How do I know if the house won't be overheating in summer, and if
that can't be controlled with the swamp cooler that the house has?
- As I mentioned, no windows on the North side, which is what you'd
expect with passive solar. But the house has a pretty decent backyard
with a patio, and it backs out to open space with mountain views. So
I'm not sure how we'd feel about not being able to look out the
window into the backyard... I guess we'd have to find out, and if we
don't like it, add a (small) window in the back

We'll appreciate any helpful feedback.

Regards

Gordon Richmond

2005-12-21, 12:21 am

Is the seller unable or unwilling to show you a couple of years' worth
of heat/power bills? If available, they should tell the tale pretty
clearly, I'd expect.

Gordon Richmond

brady4747

2005-12-21, 3:21 am

I lived in a passive solar house in the NC mountains for two years and
it was great. We had a small propane heater for about 1300sqft and
didn't even use it that much unless it was real cloudy, even in belwo
zero temps. The design of the house(orientation, floorplan, materials)
will make a huge difference in making passive solar effective. If the
windows aren't right or the insulation isn't right, there is really not
going to be much benefit. After the windows and the insulation,
probably the next most important factor would be the thermal mass
inside the house(we had brick flooring) to hold the heat though the
night.

It sounds like this house is on the right track though. Good Luck

nicksanspam@ece.villanova.edu

2005-12-21, 5:21 pm

<bubbabubbs@yahoo.com> wrote:

>- there's a little 3-ft-wide sun "room/compartment/buffer zone"
>(not sure about the terminology here

This may be a "sunspace." Is it 3' deep and the width of the great room?

>it has floor-to-ceiling glass. Then, there are two _fairly small_
>windows between that and the great room, plus a door that you can open
>to let the warm air in from the sun room to the house.

Sounds good, esp if the sunspace has very little thermal mass. You might
improve performance by covering a masonry floor with a dark carpet and
a masonry wall with a dark curtain.

>... how do I decide how energy efficient the house is?

Ask for fuel bills. Do some calculations.

>- How do I know if the house won't be overheating in summer...

Check for an overhang to shade the south glass from high summer sun,
and sunspace venting to the outdoors, and maybe an outdoor curtain.

Nick

bubbabubbs@yahoo.com

2005-12-21, 7:21 pm

> This may be a "sunspace." Is it 3' deep and the width of the great room?

Yes.

[color=darkred]
>Ask for fuel bills. Do some calculations.

I forgot to mention: my agent found some info about the energy bills
(lowest gas bill: $10/mo, lowest electric: $23/mo, ave gas+electric:
$106/mo). Problem is, it looks like no one has lived in the house at
least for the past few months, so these figures might be artificially
low.

------------------------------
Another thing: The hose has a backup PROPANE heating system. How good
is propane heating compared to 'regular' natural gas (methane?) Pros
and cons?

Derek Broughton

2005-12-22, 10:21 am

bubbabubbs@yahoo.com wrote:

> Another thing: The hose has a backup PROPANE heating system. How good
> is propane heating compared to 'regular' natural gas (methane?) Pros
> and cons?

It works just the same (but it's more expensive), burners can usually just
be rejetted to switch from one to the other. Usually homes only use
propane if they can't _get_ natural gas, though if it's a true backup, and
is rarely used, perhaps propane works out cheaper than having a minimum NG
monthly bill.
--
derek

Jesse Spencer

2005-12-27, 4:21 am

>
>
> I forgot to mention: my agent found some info about the energy bills
> (lowest gas bill: $10/mo, lowest electric: $23/mo, ave gas+electric:
> $106/mo). Problem is, it looks like no one has lived in the house at
> least for the past few months, so these figures might be artificially
> low.

Check electric bills and fuel bills provided by the utility companies
involved for extended period. Honest seller will allow access to this info.

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