Alternative Energy projects

[3930dave]

I agree. In 1985, I built my own home, and used a double 2x4 wall (interior studs 16"OC, exterior 24"OC) with a one inch space between the two. They join only at the top with a 3/4" x 9" plate. Then put 1" of foam board over the whole outside. I did it for two reasons: insulation, of course, and because I used rough cut sawmill lumber, (had LOTS of it) which varies in dimensions. By doubling the wall, I could set the odd sizes to the inside of the wall, and keep a flat plane on the inside and outside of the wall.

Did the same thing with the cathedral ceiling part of the house. Used rough cut 2x6 for rafters....set the 'uneveness' to the inside, keep a nice flat plane on the roof side. Then cut a bunch of 2x4 blocks 14" long, and nailed to a 2x4 turn on flat. Nailed that to the side of the 2x6 butted to the plywood roof sheathing. Nailed a plywood plate to the other side. Sort of a truss deal. ( See photo below ). Gave me a nice flat plane on the inside ceiling to sheet rock, also 3 1/2" wide ( like a floor truss ), AND gave me room to installed 12" of fiberglass batt, and still leave a 2" air space for soffit air to travel up to a ridge vent !

TODAY, I'd cut back on the lumber a lot, and use spray foam extensively......that stuff is great....but it just wasn't around much in the 80's.

With access to lumber like you described, I probably would have made the same move in those days Andy.

Double walls are nice, for a few reasons. Up here, we'd fill the large cavity with insulation, and you remove the thermal connector (edge of the 2x_ framing) that you get between the exterior and interior walls with traditional vertical framing.

Modern spray foam has great performance in the industrial settings I've seen it used, it has come a long way. Not sure what the present chemistry is (off-gasing wise)..... that was a big problem way back with the Urea Formaldehyde approach..... don't know what they were thinking back then.... But I expect today's solution to be much saner.

Rgds, D.

 

[TnAndy]

The new foam is a soy based product. No off gassing like the older stuff.

 

[3930dave]

The new foam is a soy based product. No off gassing like the older stuff.

That makes sense, today.

With junk food, once they switched to vegetable based inks, I figure you're better off eating the box, than the junk food ! :thumbsup:

Rgds, D.

 

[LAFarm]

Given the chance to build new in many locations, I think a person's home should be their first alt nrg project. With correct building designs, it is easy to reduce home energy needs to a bare minimum; the need for geothermal or other expensive systems, all with failure points, is eliminated.

Here is an article about passive homes that have very minimal heating needs. The comment that they should be called "resilient" homes is true and worth considering.
Super-insulated and Passive Homes laugh at the polar vortex : TreeHugger

I live in a direct-gain passive solar home, the article is realistic, not pie in the sky stuff.

Excellent point. Design/build from the ground up to maximize passive heating/cooling features is definitely the way to go. Tremendous utility savings can more than compensate for extra expenses related to passive design - which should be minimal if any. Utilizing passive design and super-insulation allows much smaller (and less costly) back-up heating/cooling systems to be installed. Notice that you live in Maine, where I assume the winters are much more severe than we have here in Louisiana. Down here, the summers are very humid. And hot. About the only way we have to lower the humidity indoors is with air conditioning. Superinsulation, proper orientation and taking advantage of artificial and natural shading can go a long ways towards lowering the heat gain, but it does nothing for the humidity. We have to rely on air conditioning to accomplish that, which is much more affordable (requires a smaller btu unit) when all of the design features you mention are incorporated. However,when you are attempting to make an older construction home more energy efficient, changing the orientation is really difficult and ripping out the interior perimeter walls to upgrade the insulation is very expensive. Caulking and adding attic insulation usually has the best roi for starters, followed by windows and doors. If the hvac system is over 10 to 15 yrs old, upgrading it to an newer and more efficient model can lower the monthly utility bill enough to make it worthwhile - especially if you are able to schedule the upgrade during the 'off-season' (spring or fall) when the hvac contractors are not during their prime business months. The attraction of earth coupled heat pumps are their really high energy efficiency ratings and their eligibility for tax credits (federal & some states). Some utilities even offer rebates for upgrading the heating/cooling equipment or installing energy star appliances. There are some residential ECHP units that have EER's of over 40 although most are in the 20 to 32 EER range. Everything from initially designing a home for energy efficiency to retrofitting and upgrading an older, less than ideal home can pay dividends. Wish you could send us some of your winter weather down here. Around July and August would be great!!!

 

[dave1949]

Excellent point. Design/build from the ground up to maximize passive heating/cooling features is definitely the way to go. Tremendous utility savings can more than compensate for extra expenses related to passive design - which should be minimal if any. Utilizing passive design and super-insulation allows much smaller (and less costly) back-up heating/cooling systems to be installed. Notice that you live in Maine, where I assume the winters are much more severe than we have here in Louisiana. Down here, the summers are very humid. And hot. About the only way we have to lower the humidity indoors is with air conditioning. Superinsulation, proper orientation and taking advantage of artificial and natural shading can go a long ways towards lowering the heat gain, but it does nothing for the humidity. We have to rely on air conditioning to accomplish that, which is much more affordable (requires a smaller btu unit) when all of the design features you mention are incorporated. However,when you are attempting to make an older construction home more energy efficient, changing the orientation is really difficult and ripping out the interior perimeter walls to upgrade the insulation is very expensive. Caulking and adding attic insulation usually has the best roi for starters, followed by windows and doors. If the hvac system is over 10 to 15 yrs old, upgrading it to an newer and more efficient model can lower the monthly utility bill enough to make it worthwhile - especially if you are able to schedule the upgrade during the 'off-season' (spring or fall) when the hvac contractors are not during their prime business months. The attraction of earth coupled heat pumps are their really high energy efficiency ratings and their eligibility for tax credits (federal & some states). Some utilities even offer rebates for upgrading the heating/cooling equipment or installing energy star appliances. There are some residential ECHP units that have EER's of over 40 although most are in the 20 to 32 EER range. Everything from initially designing a home for energy efficiency to retrofitting and upgrading an older, less than ideal home can pay dividends. Wish you could send us some of your winter weather down here. Around July and August would be great!!!

I have always suspected that capturing and holding heat in the north is easier than avoiding heat and humidity in the south. I have no experience with southern living in the eastern US. The traditional southern wide wrap around porches, taller ceilings and such are a real contrast to the generic modern home that relies on energy hungry AC.

Lots of insulation, shading, and solar electric to power the AC system would be my first guess in how to tame hot, humid conditions. High humidity takes away the ability to use evaporative cooling, which is much less power hungry than running compressors I guess.

 

[LAFarm]

I have always suspected that capturing and holding heat in the north is easier than avoiding heat and humidity in the south. I have no experience with southern living in the eastern US. The traditional southern wide wrap around porches, taller ceilings and such are a real contrast to the generic modern home that relies on energy hungry AC.

Lots of insulation, shading, and solar electric to power the AC system would be my first guess in how to tame hot, humid conditions. High humidity takes away the ability to use evaporative cooling, which is much less power hungry than running compressors I guess.

Couldn't agree with you more! Solar electric panels were the latest attempt (successful) at lowering my monthly electric bill. They have worked great and are currently generating all of the electricity we use at our home. Net metering allows us to send excess kw to the utility during the daytime - the peak demand hours - which they sell to our neighbors for retail, then we are able to use some of that back at night when the demand load is lower. Have read accounts of other homeowners who have bad experiences with solar systems, but have to say that my experience so far has exceeded our expectations.

 

[dave1949]

Couldn't agree with you more! Solar electric panels were the latest attempt (successful) at lowering my monthly electric bill. They have worked great and are currently generating all of the electricity we use at our home. Net metering allows us to send excess kw to the utility during the daytime - the peak demand hours - which they sell to our neighbors for retail, then we are able to use some of that back at night when the demand load is lower. Have read accounts of other homeowners who have bad experiences with solar systems, but have to say that my experience so far has exceeded our expectations.

That's great! There is so much untapped potential in home solar electric power, I hope the installations continue at an increasing pace where they make sense. I don't know how someone could have a bad solar electric experience if the site and installation are correct.

We have a 4.2 kW grid-tied system with net metering. It will be two years old this July, we couldn't be happier with its performance. In 2013 it supplied 88% of our power use.

 

[3930dave]

That's great! There is so much untapped potential in home solar electric power, I hope the installations continue at an increasing pace where they make sense. I don't know how someone could have a bad solar electric experience if the site and installation are correct.

We have a 4.2 kW grid-tied system with net metering. It will be two years old this July, we couldn't be happier with its performance. In 2013 it supplied 88% of our power use.

You are likely careful with your electric use, but even so, that is great performance Dave !

Rgds, D.

 

[dave1949]

Related information:
Will plug-in cars crash the electric grid? Not with newly proposed system -- ScienceDaily

How the grid could handle large numbers of plug-in electric vehicles.

 

[3930dave]

Related information:
Will plug-in cars crash the electric grid? Not with newly proposed system -- ScienceDaily

How the grid could handle large numbers of plug-in electric vehicles.

That mulitplexing makes sense. Amongst all the housekeeping required in a plan like that, I'd want to see some kind of "grid availability" data available, down at the car level. Meaning - if a mechanic needs to figure out if there is a charging problem with a vehicle, one thing he'd need to know is "Grid Availability %", for each of the last 20 or so charge cycles.

Otherwise, you can end up condemning car hardware, when the only issue was grid congestion.

Looks like we've found yet another use for standby generators....

Rgds, D.