Past Project: Solar Hot Water System

On the living room sofa; cloudy, 53.1 F, 0526

Using electricity to heat water is fairly expensive, as I discovered when we received our first electric bill. Solar hot water systems harvest energy directly from the sun and are an efficient, inexpensive way to save money.

Bolting down solar collector to roof

My friend, Jay and I installed these solar hot water collectors in August 2007. They are Model AE-40 collectors made by Alternative Energy in Jacksonville, Florida. As the name implies, they have about 40 square feet of collector area.

Collectors installed, tilted 40 degrees for better efficiency

System Design

This is a drain back system that uses water as a heat transfer fluid. The differential controller monitors the temperature of the bottom of the storage tank and the top of the solar collector. When the differential temperature is greater than 15 degrees F, the pumps turn on. Pumps move the water through a heat exchanger thence up to the collector removing the heat back to the drain back tank. A second, smaller pump moves water from bottom of the storage tank through the heat exchanger thence back into the top of the storage tank. The drain back tank acts as a reservoir. When the large pump shuts off, the collectors empty out thus preventing freeze damage.

The system diagram:

System Diagram, drain back solar hot water system
System Diagram, Drain back solar hot water system

Cost and savings

The total cost of the system was right around $5,000.00. I received a Federal Income tax incentive of $1,500.00 and a New York State Income tax incentive of $1,250.00 making the net cost $2,250.00.

It reduced our electric use by approximately 3,500 KWh per year or 45.5 MWh over thirteen years. Electricity rates fluctuate over time however, the average rate over the last thirteen years is about 15.5 cents per KWh (includes delivery charge). That is a $7,050.00 reduction in my electricity bill and is a net savings of $4,800.00. Thus this solar thermal system has paid for itself thrice over.

The US Energy Information Agency notes that each KWh generated in the United States produces 0.99 pounds of CO2 emissions. A reduction of 45.5 MWh represents a 22.5 ton reduction of CO2 emissions.

Past Project: Back deck

Living room sofa; cloudy, 46.4 F 0617

With the new well installation completed, I built a small deck for the back door. This area was an eyesore since we moved into the house. It was the main entrance and there was a large step to get in. When my friend Jay took the deck off of the back of his house, he asked if I wanted to salvage any wood from it. That was all it took to get moving.

Back entry area

Jay’s old deck lumber was pressure treated and in good shape. I saved a fair amount of money by using it. I had to remove some deck screws and clean it up a little bit. The sonotubes, rebar, hangers, ready mix concrete and the decking from one of the big box hardware stores. Truth be told, Trex composite decking would have been a better choice. The pressure treated decking lasted 13 years before it started rotting out. This was even after applying Thompson’s Water seal, which was another mistake. Live and learn.

Doing this the correct way required a building permit. No problem.

Sonotube, rebar, J bolts, etc
Sakrete ready mix concrete

Sonotubes are six inches in diameter. Digging the footings was a bit arduous. I rented an earth auger, however, there are so many rocks that I ended up digging them mostly by hand. Footing depth is four feet to get below the frost line. I put some crushed stone in the bottom of each footing for better drainage.

Sonotube, ready to be inspected

When the footing forms were in place, I called the town code enforcement officer for a pre-pour inspection. Using the chart on the side of the Sakrete bag, I calculated two and one thirds bags per footing. I mixed that by hand in a wheel barrow then dumped the concrete into the form.

Leveling the sonotube footings
Deck footings poured

Twenty four hours later and we have deck footings!

I put several inches of crushed stone and a drain pipe under the deck. This is around the side of the house were water tends to collect during heavy rain.

Gravel and drain pipe

The framing went pretty fast. I bolted a 2 x 10 header to the house. It took a few evenings to complete the frame then put the decking down.

Header bolted to the house
Basic frame
The frame is supported by 6×6’s salvaged from Jay’s house
Installing the joists, salvaged 2 x 8 lumber from Jay’s house
Framing complete, ready for inspection
Decking installed

Overall the end result came out nice.

Finished

I installed the railing because I like the look. Building code does not require a railing unless the deck is more than 21 inches above ground level. I put chicken wire around the deck, buried to about 8 inches deep to keep critters from moving in under the deck. There are a lot of skunks around and it would be unpleasant to have one underfoot by the back door.

Past project: Yard drainage and roof runoff

Home office; cloudy, fog/drizzle, 48F 0643

Any area where water does not readily seep into the ground will have to deal with runoff. In urban areas, roads, parking lots, roof tops, generate a lot of run off that needs to be routed to a dispersal system. Otherwise large unsafe unsanitary ponds will develop.

Our soil is mostly clay. When it is dry, it will absorb a certain amount of water until it is wet. After that, everything just stays on the surface. As the house is built into the side of a slight slope, water running across the back yard tends to run into the foundation. Water from the roof on the back of the house also contributed to the foundation water. All of this contributed to the repeated basement flooding encountered the first few years we lived here.

The equivalent flat area of the roof on the house is 2,052 square feet. I like data, so to quantify the problem, I made the following chart to show how many gallons of water comes off of the roof for every 1/10 inch of rainfall:

Rainfall amount (inches)Cubic inchesGallonsLiters
0.129,548128485
0.259,096256969
0.388,6443841,454
0.4118,1925121,938
0.5 – 1/2147,7406402,423
0.6177,2887672,903
0.7206,8368953,388
0.8236,3841,0233,872
0.9265,9321,1514,357
1295,4881,2794,842
Gallons per 1/10 inch of rainfall

Some of the water in the first 1/10 inch of rain goes towards wetting a dry roof down. I estimate that to be 1/2 of the first 1/10 inch stays on the roof and eventually evaporates. Everything else runs into the gutters.

As you can see, an average storm of 1 inch of rain produces 1,219 gallons of runoff from the roof alone. When larger storms arrive and the ground becomes saturated, then real problems can happen. During Hurricane Irene in late August of 2011, we received approximately 10 inches of rain in 12 hours. The basement sump pumps could not keep up with the incoming water and at one point the basement was flooded with 18 inches of water. Fortunately, the power stayed on and eventually it stopped raining and the pumps did their work.

The first thing I did was install drain pipes to take the water gutter down spouts and conduct it away from the foundation to the downhill side of the yard. To do this, required a small excavator.

Digging trenches for drainage pipes, Cat 303 Excavator

From each corner of the house, I installed 3 inch DW PVC pipe, 18 inches in the ground. The pipe on the north side of the house also connects to the sump pumps, thus that drains into a small dry well in the front yard. Unfortunately, I cannot find any pictures of laying the pipe.

Dry well with water cleaning plants

When we bought the house, only the back had gutters. It seems the previous owner had made some attempts at routing the water away from the basement. I hired a company who came and installed Seamless Gutters on the entire house, which was well worth it.

I also dug up a good bit of asphalt around the back of the house which was a patio of sorts. That was hauled off to the recyclers.

Retaining wall and drainage swale to east of house

The run off from around the yard was directed away from the house by use of two swales; one to the south and another going from east to north. The east to north swale was completed as part of building the patio and retaining wall.

This made a difference in the amount of water getting in the basement, however, there was still water getting into the basement…