NEW RECORD HIGH IN STORAGE, 155 DEGF!!, THANKS TO NEW EVAC ARRAY!!

As of June 2004, the total amount of oil and electricty we have saved from December of 1994, which is when the first solar collector went on line is as follows:

5929 Gallons of oil @ 1.10 Avg cost = $6,522.00
24,272 KWH @ $.08 Avg cost =         $1,941.00
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                                                   $8,463.00 Savings

Just to give you an idea of my energy expenses, I spend about $200.00 a year for heat and hot water (Now about $325) and about $60.00 to $70.00 a month for electric. I do not burn wood or coal or any other fuel besides my oil backup heat, which equals about 40% of my total energy for heat and hot water. The other 60% is solar. My final goal for the house is a 75% solar, 25% electric Geothermal backup. See the SAHP page for details.

The Berwick Solar Home in Berwick, Pa is all retrofit. All the solar additions and insulation changes were made well after the initial construction date back in the 50's. The original specs. are as follows:

House dimensions are 30'x40'. Basement: 8" block no insulation. Rough concrete floor.

First Floor: 2"x4" studs, R11 Fiberglass batts. Single pane windows with storm windows. 1/2" drywall inside. 1-1/8 hardboard sheathing, vinyl siding over cedar siding with 1/4"eps underneath vinyl siding.

Attic: 2"x6" floor joists, R19 fiberglass batt with old 2" fiberglass underneath, total 8" ~R22.

Heating Systems: 52 gallon electric water heater, Lenox oil fired hot air furnace, 275 gallon oil tank. Old dial type thermostat.

House specs as of 4/1/2004:

House dimensions are 30'x40'. Basement 8" block, insulation on walls 1-1/2" R11 foam with 3-1/2" or 6" fiberglass batt over foam, total R value R22 to R30. Concrete floor re-done with ceramic tile on top.

First Floor: 2"x4" studs R26 foam, double pane windows with Heat Mirror 88 film and Argon gas. 5/8" drywall, 1-1/8" hardboard sheathing with vinyl siding over cedar siding with 1/4"eps underneath vinyl siding. Approximately 1/2 of first floor done to new spec..

Attic: 2"x6" floor joists, R19 fiberglass batt with old 2" fiberglass underneath, cross studded with 2"x4" lumber with blown in cellulose insulation, total R value ~R34, 1/2 plywood flooring.

Heating Systems: 200sqft active solar hot air collector, 70sqft. evacuated tube tracking liquid collector, all integrated with a 3000 lbs water storage tank. Backup heat is an oil fired 32 gallon Brock water heater tied to a Rheem air handler.

Current heat distribution 60% solar, 40% oil. The goal set for the final heating distribution is 75% solar, 25% oil or high efficiency heat pump mixed with 2kw/hr of PV.

Hot Air Collector:

200 Sqft Hot Air Collector after initial completion back in December '94.

Photo shows air flow channels and baffling to cause turbulence in the air flow to improve heat transfer from aluminum collector plate to air flow.

Blower and its box where hot air is pulled from collector. Blower puts out 600-800 CFM. Maximum air temp is around 140 DegF. Blower box is mounted in old window hole enclosed behind collector.

The hot air collector pictured, was the first project chosen for the homes energy makeover. I chose this as the first, because the impact to the other areas of the house were minimal, yet the effect on oil usage would be large. I decided not to use glass as the glazing for several reasons. Weight and danger from breakage due to the size of the collector and its location, were two main factors. Another was that I wanted something more transmittive than glass. Ultimately I chose Teflon. Its durability under sunlight, "zero weight", extreme clarity to the suns energy (96%+), were the major benefits. By using a film type glazing, the support structure for the glazing mounting would virtually disappear. The aluminum collector itself is comprised of three sheets of corrugated Aluminum 16’ x 4’ running horizontal. When the collector is finally complete, it will have three layers of Teflon, with three separate air spaces. At present it has only one. Even with three layers, 85% solar transmission will be maintained. Currently the output air maximum is around 140 deg’s F at a flow rate of about 600 to 800 CFM.

The size of the hot air collector was determined by the general rule of thumb of 1 sqft of collector for each 10 sqft of heated floor space. Approximately 2000 sqft to heat, therefore 200 sqft of collector. Since the photo above, a concrete patio has been added. During the heating season, which is when the hot air collector is active, I put aluminum reflectors on the patio which bounce extra solar radiation onto the collector. The gains are about 10 to 15 degrees in output air temp. The collector did not have any storage initially tied to it. This was to come with the introduction of a year round liquid collector. The goal was always to put a 3.5 meter parabolic tracking collector for the liquid part, coupled with the appropriate size water storage. But the parabola project was not going to be complete, perhaps for a long time, so I opted for a simple 4’ x 8’ copper flat plate collector. This would allow the whole system to be completed. Operationally, all testing could be completed and all "bugs" could be eliminated. The benefits of storage could start to be realized, although the heat values into storage would of course be much less than with the dish unit.

The hot air collector worked so well, even with its single layer of Teflon, that it was necessary to extract some excess heat from it once the liquid storage and liquid system came on line. This was done with the addition of a heat exchanger between the air collector and the blower. In the long run, the extraction of "extra" energy from the hot air collector would not be necessary. When the basement level was complete from an insulation and drywall perspective, about 50% to 75% of the hot air from the collector would be shot down there directly eliminating upstairs overheating. Secondly, the box temperatures are expected to average in the 100+ range most of the time when the dish comes on line, that only a minimal amount of heat be gained, not enough to justify the pump energy used for the extra circulation.

The tracking evacuated tube collector which has been on line since 9/21/2004, can be viewed as an intermediate project, replacing the 4'x8' flat plate collector. Box tempatures are already substantially higher. This year, Winter 2004-2005 I am not using reflectors and I am trying to get the extra Teflon glazings in place, finishing the original design concept.

Liquid Collector:

First liquid collector went operational back in June '99. Collector was recently replaced by collector pictured below.

High efficiency evacuated tube collectors went on line 9/21/2004. There are two units mounted on the East-West tracking array. Initial data looks very impressive. The total weight of the array is about 550 pounds and measures about 7'x12.5'.

Water Solar Storage Tank, Oil backup heat:

The water storage box pictured, is made of 1-1/2" plywood (2 - 3/4" material laminated together) coated inside with epoxy paint and fiberglass on all seams. It stands 4’ tall, about 5’ deep and 30" wide. The exact inside volume is 46.32 cubic feet @62 pounds per cubic foot is 2871 lbs. With some copper, bricks and steel inside I round it off to 3000 lbs. of water or 3000 BTU’s per deg. F. change. The box has 120 feet of ½" copper tubing which serve as a heat exchanger to put heat into the box as well as take it out. When the exchanger fluid is in heat delivery mode, it flows from the top down. When in extraction mode, it flows from the bottom up. This gives the exchanger a degree of counter flow functionality, since the box is always warmer at the top than at the bottom.

The 20 gallon stainless steel tank in the second photo sits in the center of the box in an upright position. Well water on the way to the oil fired water heater, flows into the bottom fitting of the stainless tank and exits the top. Having a "cold" source in the center of the box, and the hot coils on the sides of the box, serves to set up a convection loop which further increases heat transfer efficiency.

The third photo shows the completed box. With the 1" extruded polystyrene insulation (R5) inside and the 1" fiberglass insulation (R4) on the outside, plus a little R value from the wood itself, the bottom and sides are rated at R10 total. The top is 3" of foil faced polyurethane (R22). Approximately 15 gallons of ethylene glycol (regular car antifreeze) was added to the water in the box for bacteria control. This also doesn’t hurt when it comes to corrosion resistance. The Brock oil fired water heater sits to the right of the box, the Rheem air handler over the top, and the 275 gallon oil tank to the left. The box was designed to fit right in the space created by those three system pieces. The air expansion tank, pressure gauge, fill ports (in and out), and some of the plumbing are located on the front end of the box. The Rheem air handler above, was fitted on the front with a Snowmax heat exchanger, which is how the heat from the box is transferred to the air on its way to the main heating coils for the homes space heating. The warmer the air before it hits the main coils, the less the oil burner runs.

The fourth photo shows the pumps and control relays for all the solar collectors.

Bock Oil fired water heater installed in December of '95. As mentioned above, the solar water storage and liquid collector didn't go on-line till June of '99. The little clock seen on the top of the water heater, only runs when the oil burner itself runs.

The oil fired water heater shown above, is a Bock 32 gallon, with a .75 GPH nozzle installed in the burner. The heater is tied to a Rheem air handler which provides the space heating for the home. A Snowmax heat exchanger was placed on the front of the air handler to preheat the air on its way to the main heat exchanger. The fluid running through the Snowmax is solar heated from the box water storage. A 20 gallon stainless steel tank within the box (see storage picture) preheats the well water before it goes to the O.F.H.(oil fired heater). The clock shown in the photo sitting on top of the heater, only runs when the oil burner is running. It is reset everyday, so the total oil burner runtime can be recorded each day. This piece of data coupled with storage temps., provides much of the information for the solar systems effectiveness (see detailed graphs) in reducing oil and electric usage. The O.F.H. ‘s plumbing is such that it can be isolated for cleaning or failure with the twist of two stainless steel ball valves. The box water storage also has the same capability. The entire system is designed in such a way that the failure or maintenance of one major part does not effect another, so you always have a source of heat. The vent pipe for the O.F.H. has a Magic Heat heat exchanger in the stack pipe which extracts heat from the waste gases. The chimney temp usually is between 150 and 300 degs. F., which is "cool" for an oil burner.

Data Graphs and Analysis:

This graph shows oil purchase dates and amounts. The number at the top of each bar is the gallons per day used for that period of time.
The solid line is a moving average trend line. Key system changes are noted above relevant time period.

New SAHP 96 sqft ground feed array. Array went operational around 10/20/2005. See SAHP page for details.