Homeowner's Blog » Environment

Barn Project, Part IV pouring the slab

Paul — Thu, 16 Feb 2012 13:09:59 +0000

With the frost wall back filled and the center of the foundation filled it, it was time to get ready to pour concrete. The first thing that went down was a vapor barrier, consisting of 20 mil poly plastic.

Then 4 inches of polyisocyanurate insulation with a foil backing. The hollowed out sections of concrete block were filled with vermiculite.

Ready to pour concrete

A layer of 4 inch steel mesh wire was laid on top of the insulation, held up with medium sized rocks. Attached to the mesh was 1/2 inch pex for in slab radiant heating. Finally, the outside of the block wall was formed and 1 inch of foam insulation was run around the outside.

Pouring concrete for slab

Finally, it was time to pour concrete. In an almost surreal moment, the temperature moderated and on Friday, January 13th we were able to pour the slab in 56 degree weather. Overnight, the temperature went down to 34 degrees then back up to 56 the next day. If this is climate change, I am not complaining.

Barn Project slab poured

The total slab was about 8 cubic yards, 240 inches x 192 inches x 8 inches = 368, 640 cubic inches or 7.9 cubic yards, which cost $709.00 delivered, mixed and poured by the ready mix truck. Thankfully, the previous night had been cold and the ground was frozen solid. The entire pour took about 45 minutes. Since the weather was warm and forecast to stay above freezing, I did not get accelerant added to the mix. By 4 pm, it was hard enough to smooth finish.

I kept a tarp over it for three days.

The total cost for the insulation, reenforcing wire, pex, concrete and labor was $2415.39

The running total $5,156.62

Installing our Photovoltaic System, part V

Paul — Tue, 09 Feb 2010 16:06:05 +0000

Inspections. There are three inspections. When scheduling the inspections, thou shalt count to three, no more, no less. Three shall be the number thou shalt count, and the number of the counting shall be three. Four shalt thou not count, neither count thou two, excepting that thou then proceedest on to three. Five is right out. Once the number three, being the third number, be reached, then you are done.

The inspections satisfy some needed safety concern. The first inspection is the electrical inspection. I know the local inspection agency from several other projects and they are familiar with my work, so this one usually goes pretty easily. I hand him the three line drawing, he looks it over, we catch up on things, he peers into the disconnect switches, shakes the ground wire, looks at the service entrance panels, asks how I like these new inverters, etc. It usually ends with “nice work, that will be $120.00, certificate is in the mail” and he is off.

The next one is the utility company inspector. They already have the paper work that was submitted with the application for a net metering account. Generally, they come out and verify the inverters shut down during a power outage, then proceed to write every scrap of information down that they can find, disconnect switch ratings and model numbers, inverter power factors, breaker ratings, etc. They stand in the yard and peer up and the panels, point and mumble amongst themselves. Fortunately, there is no charge for this inspection.

The final, final inspection is with the town building code enforcement officer. He comes out, looks at it, asks for and receives a copy of the electrical inspection certificate. Asks if everything is installed the way the manufacture specifies, looks at it some more from a different angle, then knocks it twice with the heal of his hand and says “Yup, that isn’t going anywhere.”

A few days later the certificate of use arrives in the mail and the project is done! Yay!

So, now for a few exciting things, first of all, if you have never witnessed a power meter turning backwards, here is a little video:

This is a video of the panels in action, generating power:

Finally, this is a monitoring page from my solar company website. It shows how much power each panel is generating, how much power the system has generated and what the peak power output is on any given day.

Catskillhouse PV system

www.sun-volt.com/pages/pvmonitor.html

That site has pictures of the system and a three line diagram.

Installing our Photovoltaic system, part IV

Paul — Fri, 08 Jan 2010 23:37:50 +0000

Now for the fun part, the frame is all done. The frame is pressure treated 4×4 post and beam style. The rafters are pressure treated 2 x 10 x 12 feet. Over all, it came out pretty nice. Next year I intend to replace the front deck with a covered porch, also post and beam style, so this should match the look of the house.

Front view of 4.1 KW PV system

Ground mounted 4.1 KW PV system

This system is 4.1 KW and should provide almost all of our electric needs once we replace the old refrigerator with an energy star unit.

Enphase M-210 inverter under Sanyo HIP205NHKA5

I used Unirack Sunframe rails to mount the PV modules. The modules are are Sanyo HIP 205NHK5 Modules and Enphase M-210 microverters. I like the concept of the Microverter, e.g. each panel has it’s own small inverter. This allows from some shade tolerance for the lower modules without loosing the entire array. Also, each panel is matched to it’s inverter at the best efficiency, increasing the overall array output. Seldom do you get to see the underside of a PV array as they are most often mounted on a roof.

Installing our Photovoltaic system, part III

Paul — Tue, 22 Dec 2009 00:12:29 +0000

Constructing the mounting frame. I had my one “oops” moment in the project already, hopefully there will not be another one. It seems that when I laid out the position of the mounting frame, I was a little too close to the property line. In the end of October, the town that I live in changed its zoning code, making side line set backs 40 feet. The previous code stated it was 10 feet for “unenclosed” uses, e.g. swimming pools, fences, etc. Since the mounting frame is not enclosed, I figured I would be good at 30 feet. No good, the whole thing had to be moved back 10 feet.

Equally unfortunate is the fact that I jumped the gun on the construction and poured the footings before I had the building permit. So, once again I rented the Kabota backhoe from the Taylor rental place down the road. I am on a first name basis with the owner, which is nice, sort of. Anyway, quick work with a chain and I pulled all six of the eight inch footings out of the ground, dug new holes and place the pre-poured footing in a new whole. I dumped about 6-8 inches of crushed stone in each hole an compacted it. All in all, I am only out the one day’s rental on the back hoe, which was not too bad.

Timber Frame for 4.1 KW Photovoltaic system

On to the construction of the frame. I decided to use 4 x 4 posts and beams, except for the main support beam, which is 4 x 6 inch. The entire structure is braced with 4 x 4s at all ninety degree meetings.

Corner bracing

Of course, the weather has closed in and I am working outside in the snow and wind. On Saturday, it was 15 degrees out with a 20 MPH wind. I don’t know what the wind chill was, I can however verify, it was unpleasant working outside. That being said, progress has been made.

The frame is mostly up, I need to put the final support beam across the top. Then I need to put in the “rafters” which will be 2 x 8 x 12 treated lumber. The rafter spacing will be a little odd, since they are space to support the solar panels according to the panel manufactures specifications.

Hand dug conduit trench

Also completed (before the ground froze solid) is the trench between the house and the support frame. We dug this by hand, 42 feet long by 18 inches deep, as the current NEC specifies for PVC conduit.

Everything is frozen solid right now, which actually has it’s advantages. Come springtime, this will be a soupy mud mess. Once the ground drys out a little bit, I’ll rake it out and plant some grass seed.

Installing our Photovoltiac system, Part II

Paul — Sat, 21 Nov 2009 19:14:55 +0000

Laying out the support frame. As mentioned before, the south facing roof on our house is taken up with the solar hot water system. The only mounting option for the photovoltaic system was to build a sun shade type support frame in the yard.

The first thing that was needed was the size of the array. For this system, we will be installing 20 Sanyo HIP-205N modules. These measure 62.2″ x 31.4″. I would like these to be installed landscape style, four deep by 5 wide. The total array size is 311″ or 25.9′ X 125.6″ or 10.4′ I am leaving a little room around the edges for a safety factor, so my support frame will be 27 x 12 feet.

I also want to tilt the array to latitude, which around here is 42 degrees. There have been studies that show that the tilt angle is not a critical as once thought, however, since I can do it, I might as well. Therefore, I will install a total of six support posts, making the structure 26 feet x 7 feet. The front of the structure will be about 6 feet above ground level, the back will be about 12 feet above ground level.

PV system location marked with stakes

I staked out the frame and aligned it to true south. It is only a few degrees off from the property line, so it works out well. Since we have had a lot of rain this year, I decided to dig a test pit to see where the water table is in relation to the bottom of the footings. Local code requires 48 inch deep footings, my test pit reached 46 inches deep before I saw some seepage. I left it over night and the next morning there was about 2 to 3 inches of water in the bottom. Over all, not too bad, I put some crushed stone in the bottom of each footing before I put the form in.

Test pit to see where the ground water table is

It rained most of the day on Saturday, however, I still managed to dig four of the six holes. On Sunday, I dug the last two. Then, by this post, I knew that it takes about 2 2/3 80 pound bags of ready mix to fill an 8 by 48 inch sonotube. I picked up 16 bags of 4000 PSI ready mix. This time, I borrowed a cement mixer, which made things much easier. I also used one #4 (1/2 inch) rebar down the middle of each footing, tied to the J bolt on top. I used 1 gallon of water per 80 pound bag, as the directions on the bag stated. This made a good stiff mix.

Holes completed, string crosses mark footing locations

To make all of the forms the same level, I used a 14′ 2 x 8 and a level. Going from hole to hole, slowly putting more packed crushed stone in each hole, I think I got pretty close. Also, the crushed stone will aid with drainage around the bottom of the footing. Any differences in level can be made up by trimming the posts.

Footing hole, somewhat deeper than 48 inches

This was a miserable job. It was wet and muddy all day long. One of the hole had a lot of water in it, which needed to be pumped out before I could put the form in. Our soil is thick clay, which caked on everything, shovels, boots, rocks, etc. The weather forecast was for sun on Sunday, which turned out to be false. Still, it is done.

Footings completed and backfilled

I was going to use the excavator to dig the trench for the conduit, however, I decided that a ditch witch would be a better idea, less back fill, less mess, etc. For conduit, I think I will go with two inch. This system has microverters, which means the feed from the solar array will be 240 VAC. I could use #12AWG with this and come in at just under 2% voltage drop. Since I have spools of #8 AWG already on the truck, I will used that cable instead. That makes the voltage drop 0.6%. Since there are two 240 VAC branch circuits, plus two neutrals and one ground wire, that makes the total number of conductors 7. According to the latest version of the NEC (2008), table C.10, 1 1/4 inch schedule 40 PVC conduit is acceptable for this installation.

Once the concrete hardens for a couple of days, we’ll put up the frame.

Installing our Photovoltaic Solar System, Part I

Paul — Thu, 12 Nov 2009 01:08:29 +0000

I have had a pretty good year with the solar business thus far. Therefore, I decided to roll some of this year’s profits into our own Photovoltaic (PV) system. This idea has been batted about before, including as a battery back up for the sump pumps, however, a few things have developed since then.

First of all, as technology often does, newer things are available these days that make a solar system in the North East a better proposition. Secondly, the solar business has done better than I expected. As a result, I don’t often have much time to work on household projects. That means that this years “capital improvement” budget has gone unspent for the most part. Finally, I would like to offset some of the extra income tax from the profits. What better way than to invest in the technology myself. The Federal Government offers a 30% income tax incentive and the NY State government offers a 25% tax income incentive up to $5,000.00. This will cut the overall cost of the installed system by almost 50%.

There are a number of considerations:

How large of a system should be installed. I decided that I wanted to offset 70-80% of my annual electrical use. In this climate and environment, that equates to about 4.1 KW DC PV system. This leaves a little downward room in case I decide to replace the electric stove with a gas unit.
Where can it be installed. Since the south facing roof has the solar hot water system, the PV system needs to be mounted on a sun shade type structure in the yard.
What type of technology. I was initially looking at a grid tied with battery back up, however, after I looked into the newest type of inverter, the Enphase microverter, I decided that this was the way to go. A battery backup can be added at a later date.

The Enphase microverters are really cool. The way this system works is every solar panel has its own small inverter instead of one large inverter for many panels. The advantages of this type of system are thus: In conventional system, shading of one panel can cause the entire solar array to turn off, making it ineffective. With the microverters, the shaded panel may turn off, but the rest of the unshaded panels still put out full power. In the Northeast, trees grow everywhere, it is nearly impossible to have a completely shade free site, nor should home owner’s be expected to clear cut their lots to accommodate a PV system. The Enphase microverters mitigate some of those concerns.

Also, multiple inverters create redundancy. Any one inverter can fail, leaving the other nineteen still operational. There is automatic web monitoring for a small annual fee, or the modules can be monitored manually. I may write a small web based program to monitor and post my energy output here. The inverters themselves carry a 15 year warranty, whereas most other inverters carry a 5 year warranty.

Finally, there are no DC voltage losses to account for, making the entire system operate much more efficiently.

In anycase, the order has been signed, checks have been written and the excavator has been reserved for this weekend. The first step is to dig and poor the footings for the sun shade.

More to follow.

Degradable plastic bags

Paul — Sat, 13 Jun 2009 19:35:25 +0000

I was reading something this morning about how the City of Philadelphia is considering baning plastic bags completely. It seems that those thin plastic bags you get from the grocery store are public enemy number 1 when it comes to the battle over the protection of the environment. It is truly fascinating to see the things that people focus on, anybody up for re-arranging some deck chairs?

So why not, there is little else going on these days. I mentioned the above to my lovely and talented wife, who stated that she got a “degradable” plastic bag from the local organic grocery store. So I examined said bag and found the statement “This bag will degrade into many small pieces when exposed to sunlight.”

explanation on plastic bag about why this bag is "green"

I don’t know if you can read that or not.

Many people might call these bags “biodegradable” which they are not. “Bio” would indicate that some living thing could act on the structure of the plastic, breaking apart into different compounds and base elements. I would call these bags oxi-degradable, which means that sunlight will oxidize the carbon chains into CO2 thus breaking apart the structure of the plastic. It also mean in an non-oxygen environment, such as being buried in a land fill, or under water somewhere, these bags will be every bit as resilient as their non-degradable counterparts.

The other question is time period. Anything will degrade over time, the question is how long? One day, one week, a year, a decade… To answer this question, I staked the degradable plastic bag out in full sun light.

degradable plastic bag in full sunlight

I’ll post a follow up when it dissolves into many small pieces.

Update: July 1, 2009. No noticeable degradation.

Update 2: July 13, 2009. No noticeable degradation.

Update 3: July 31, 2009. Bag is falling apart:

degradeable plactic back after 6 weeks in the sun

After 48 days, the bag is disintegrating rapidly. I will also admit that we have had a wet rainy summer and the sunlight has not been as intense as it normally is. That being said, I stand by my assertion that if these bags are buried in a land fill or in an anoxic environment, they will not degrade at all.

Still, it did do what the manufacture said it would, so I’d say they are an improvement in plastic bag technology.

Clean burning woodstove

Paul — Tue, 13 Jan 2009 13:36:17 +0000

I took this picture of our wood stove chimney. Once the little Jotul F100 wood stove gets hot this is the way it looks:

wood stove chimney with fire going

Clear. According to the US EPA certification sheet, (large .pdf file) the Jotul F100 Nordic QT puts out less than 3 grams of particulate matter an hour.

non catalytic wood stove diagram

Very little particulate matter is released from this stove because it has a baffle. When the fire box is above 400 degrees or so, all of the smoke is burned in a secondary combustion because the baffle mixes the wood smoke with fresh air at a combustible temperature. This means that the stove is much more efficient, safer, and better for the environment. If the smoke were not burned it would condense as creosote on the inside of the chimney.

Jotul F100 Nordic QT wood stove at operating temperature

Wood creosote is a brownish yellow sticky substance that is essentially condensed wood smoke. Since wood smoke is combustible, wood creosote is also combustible. In fact, it is a bad hombre, leading to chimney fires that can burn down a structure. It is the reason why every wood burning appliance needs to have it’s chimney cleaned and inspected annually.

A properly installed, clean burning, UL listed, EPA certified woodstove is good for the environment as they produce no nitrates or sulfates while operating. They are a great way to save some money on heating, especially if the wood source is free.

Solar Hot Water Energy Savings

Paul — Sun, 26 Oct 2008 18:22:38 +0000

solar domestic hot water system

My Solar Hot Water System has been on line for one year now. I thought I’d post some results on the energy savings thus far:

Before the solar hot water system was installed, we used on average 32 kWh/day. This is a three year average and it was pretty consistant. Now that we generate most of our hot water by solar instead of electricity, our average useage for the last 12 months has been 23 kWh/day. You might say, big deal… 9 kWh per day. We are now paying ¢18.3/kWh. Therefore 9 kWh x 365 days is 3285 kWh or at our current electrical rate, $601.16. This puts it right in the range I was expecting and agrees with all of the calculations I did beforehand. I love it when that happens!

What is even better, over the summer, the electric rates were peaking because most of our electric is generated by oil and natural gas. It was durring those months that we saw the most savings, our electric use dropped to 15 kWh/day vs. the previous 3 year summertime average of 28 kWh/day.

My payback time should be less than 4 years.

DIY solar panels, Part II

Paul — Wed, 08 Oct 2008 23:16:45 +0000

This is part II of how to make your own solar thermal collector to help offset heating costs this winter. You will need a good south facing wall to mount this collector on. In order to be most effective, the wall should be unshaded between 9 am to 3 pm daily. Some defused sunlight shining through the branches of a deciduous tree is fine.

Preferably this collector will be mounted adjacent to a large reflective surface. A snow field would be perfect, however, dry sand, concrete and water will also work. The quality of the reflective surface is called Albedo, which in Latin refers to its “whiteness.”

Here are some albedo figures for some common reflective surfaces:

Material	Albedo (percent reflection)	Comments
Snow, new	80-90%
Snow, old	65-75%	After one week
Sand, dry	35-45%
Sand, wet	25-35%
Ice	30-40%
Concrete (dry)	50%
Water (high angle radiation)	8%	Sun angle relative to surface
Water (low angle radiation)	70-100%	Sun angle relative to surface

Also, the lower the sun angle, the larger the reflective surface should be. This is for two reasons; first, the law of reflection states:

The incident ray, the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same plane.
The angle which the incident ray makes with the normal is equal to the angle which the reflected ray makes to the same normal.

Therefore, the lower the angle of the sun the further away the reflection point will be from the collector.

Secondly, the lower sun angle also means that the energy density of the sun light is much less. A larger reflective area will aid in gathering more energy.

Solar Collector parts list:

Nomenclature	Number	Price each	Price total
Aluminum cans	560	0	0
Solar Selective coating, Dampney Thurmalox*	2	19.95	39.90
Aluminum angle 1x1x96″ 1/8	3	24.72	74.61
Aluminum metal lath 26 x 84″	2	10.67	21.34
Aluminum angle 1x1x48″m .050	4	4.98	19.92
SunTuff polycarbonate panels 26×96″	2	19.95	39.90
Polyisocyanurate insulation panel 4×8′x1″	1	23.50	23.50
24 VDC fan, 224 CFM, Mouser 5912-7114N*	1	90.55	90.55
Draft seal, 4″**	2	5.86	11.72
Diffuser, air 4″**	2	14.95	29.90
Duct connector, 4″**	2	4.20	8.40
Diffuser, air 6″**	1	15.87	15.87
Duct connector, 6″**	1	4.25	4.25
12 watt PV panel, Sunwise SC12-12*	1	143.22	143.22
Snap disk fan control switch, Grainger 4E116*	1	18.66	18.66
1x8x96″ clear pine board	3	9.32	27.96
RTB sealant	1 tube	4.89	4.89
High quality urethane caulk	1 tube	3.34	3.34

*Not required for a passive system
**Quantities doubled for a passive system

Total, active system: $447.16
Total, passive system: $355.74

All parts except snap disk switch, PV panel, and DC fan were priced and purchased at the Home Depot.

Therefore, a passive collector needs to offset $355.74 in the first year’s use, an active collector needs to offset $447.16. According to NYSERDA, the cost of home heating oil is currently $3.823 a gallon. I need to save 117 gallons of fuel oil to offset the $447.16 collector cost. Each gallon of home heating oil has 139,000 BTU. My boiler is 86 percent efficient, therefore, I get 119,540 BTU per gallon.

My solar collector needs to generate 13,986,000 BTU to save 117 gallons.

I expect the active solar collector I build to generate about 45,000 BTU per day. The heating season lasts from October through April, or 212 days. I expect 30 percent of those days to be too cloudy to generate significant heat from the collector. I have 148 days of good solar resource, so 6,660,000 BTU can be expected. That makes the payback approximately two years vs the one year original design goal.

Solar collector tools:

Ridgid MS1065LZ 10 inch miter saw

Makita 6213D 3/8 inch cordless drill

Ridgid R84001 3/8 inch cordless drill

Bosch 1587A Jig Saw

DeWalt D28110 rotary grinder

Construction details to follow in Part III