Plumbing & Heating

“The inventions of central heating and air conditioning coupled with cheap and apparently abundant fossil fuels would free building designers from considering the external environment and allow them to use brute force heating and cooling solutions to overcome building designs totally inadequate for their local climates.”

HOME HEATING IN AMERICA

For the first 100 years home heating in a heavily forested America was dominated by biomass (wood) and it was not until 1885 that the nation would burn more coal than wood. Prior to 1885 the majority of homes in America were heated with wood burning brick fireplaces and derivatives of the cast iron Franklin Stove invented in 1742.

By the end of the 19th century the invention of low cost cast iron radiators would bring central heating to America’s homes with a coal fired boiler in the basement delivering hot water or steam to radiators in every room. At about the same time, in 1885, Dave Lennox built and marketing the industry’s first riveted-steel coal furnace. Without electricity and fans to move air, these early furnaces transported heat by natural convection (warm heated air rising) through ducts from the basement furnace to the rooms above. These two methods would dominate home central heating until 1935, when the introduction of the first forced air furnace using coal as a heat source used the power of an electric fan to distribute the heated air through ductwork within the home.

To continue go to: http://sunhomedesign.wordpress.com/2007/10/26/a-brief-history-of-heating...

 

Heat from the sun: I added a solar collector to the south wall of my bilevel suburban Denver house in the fall of 2005. It's a little like a section of greenhouse stuck to the side of the house. Since there was an upstairs window practically right over a downstairs window, I didn't have to make any permanent modifications to the house to allow air circulation through the collector. On sunny winter days, I just open the upper and lower windows and set up a portable fan in one of them. Passive convection would circulate some air from the lower to upper level, but adding the fan greatly increases the heat output. collector in winter, fan running 8mm twin wall polycarbonate

Construction:

The structure is modular; a rectangular base of 2x6 redwood (tapered to conform to the irregular concrete/brick patio) sits on the concrete patio and is bolted to the house foundation. The side and front frames that sit on the base are made of ~2" x 2" weather-resistant wood -- redwood and cedar, most of which I scavenged from my scrap collection. A couple of the thin cross piece supports are cut from salvaged 1" oak flooring. All the wood panels screw together and could be disassembled in an hour or two. The translucent panels are 8 mm. twin-wall polycarbonate (Verolite brand), which is widely used in greenhouses, very strong, UV resistant, and heat transparent, though it's not cheap. The polycarbonate can be cut with a fine-toothed, plywood-type or thin carbide blade if you're careful. I mounted some lengths of sheet metal I had (salvaged baseboard radiator backs), on to the house wall, with stand-offs so air can circulate in front and back. These darkly painted steel pieces help the efficiency of transferring solar heat to the air circulating through the collector. All wood pieces were primed and painted with exterior latex paint to match the house exterior.

Winter use: Around mid-October, it becomes cold enough and the sun angle low enough to get significant supplemental heat from the collector. I monitor the air temperature in the collector with a remote sensing thermometer; around mid-morning, as the collector air gets above indoor room temperature, I open the two windows and turn on the fan, blowing air from upper into lower level. Since I'm almost always home, controlling it all manually works OK. If I weren't almost always here, I would have to install a thermostatic controller for a fan and some electrically operated vents in the windows, or figure out some other circulation system, because temperatures can vary a great deal as the cloud/sun conditions change. E.g. it can be cloudy and freezing cold at 09:30, and the collector temperature might be 28 F. degrees; if the sun comes out at 10:00 it can rise to over 110 degrees in 1/2 an hour. On the typical sunny winter day here, I'll heat my house up to 66 F. degrees (with the natural gas furnace hydronic system) when I wake up. Then, starting mid-morning, I will operate the collector about 5-6 hours, with the furnace turned off. Depending on outside temperature, I may or may not need to turn the furnace on again in the evening.

Summer setup: By early June, I don't need to heat the house, and slide out the large polycarbonate panels, and replace them with sections of redwood lattice held in by screws into the frame. I insert a custom-fit rectangular planter box in the base, and plant vines and flowers: morning glories and various beans, which over the summer, climb up the trellis and provide shade for the windows. (By mid-summer, the sun elevation is such that very little direct light would come in these windows anyway, but the trellis and vines are a nice decoration anyway.) The photo below shows the vines in mid-summer, halfway up the trellis. By late summer the vines totally cover the trellis.

Costs and savings: With all the custom fitting and angles, this was a complex carpentry project that took ~40 hours to build. I used a lot of surplus wood and hardware I had on hand, but bought a 10' cedar 4x4 that I ripped down to make the long pieces for top section and 3 4x8' polycarbonate pieces (about $2.25/sq. ft.). My total material cost was ~$300, but you'd spend about $60 more if you had to buy all the wood and hardware. How long did it take to recoup the cost in energy savings? Comparing my heating costs with the previous years', I'm estimating that I saved enough natural gas to pay for the project, more or less, in its first winter of use. Now beginning its third winter of use (2007-8) it's still working fine and I'd guess saving me a few hundred dollars a year in fuel costs.

mid-summer trellis setupcollector side detail, summer

Why: Heat rises, so near your ceiling the air is probably the warmest in your house (good reason for slow circulating fans in high ceiling houses, but that's another topic). If there's an attic above your ceiling it's probably a major conduit of heat loss in winter. Adding insulation to your attic is said to be one of the most cost-effective energy saving investments you can make. Typically the attic will also get very hot in summer, so insulating it will also greatly reduce cooling problems in summer.

 

My project: Soon after buying my 32 year old house in 1999, I realized the attic insulation was pathetically inadequate. This house has roof trusses and the original builders simply put a few inches of loose mineral (rock) wool in the spaces between the 2x4 rafters. 32 years of settling and blowing around left the remains of the rock wool in very scattered condition. Many spots were bare -- you could look right at the gypsum drywall of the ceiling below!

Extensive remodeling in this house involved new and replaced wiring, recessed ceiling lights, bathroom fans, etc. etc. that required much climbing around in the attic, over the rafters, displacing and replacing insulation. Obviously, I had to finish all those big projects before adding more inches of insulation in the attic. Therefore it was summer of 2002 before this job got done.

Choosing the method of adding insulation was easy. I wanted to leave the few inches of rock wool there -- it would be nasty to remove and why waste it? So, by far the quickest and cheapest method was to add more blown-in loose insulation. Recycled cellulose, made from old newsprint I think, with flame and bug retardent chemicals added, was the clear choice. You can actually rent machines to do this, buy the bags of material, and do it yourself. But it was cheap enough to hire a professional and I'm glad I did. They knew how to seal off the attic from living spaces below, had more powerful blowing machines than you can rent, and knew how to get even coverage. And it's a really dirty job.

The two fellows came one morning, did the whole attic and were gone by noon. I had about 1700 sq. feet of attic area, to which they added 6+ inches of blown cellulose for total cost of $668. The R-value of what they added is ~23, so my total ceiling R-value now is probably close to the recommended 30 for this area. I now have between 7-8 inches covering the entire attic.

cellulose blown insulation

Energy savings:I averaged my natural gas usage in therms for the 6 highest heating months (Oct - Mar) of 2000-2005 -- two winters before and three after attic was insulated. The average savings after insulating was 330 therms for the 6 heating months, approximately 1/3 of the total usage for those 6 months of the year (980 before, 650 after). Natural gas was pretty cheap in 2002-3, a little over $.50/therm, but has approximately doubled since then, though it spiked higher in 2005-06, it has come down a little since then. But at then current rates, my insulation project paid for itself in the beginning of third winter (fall '04-winter '05). At present gas price, the project would have paid for itself in the second winter.

depth approx 7-8"

I have five Sun-Lite Thermal Storage Tubes placed along three large, contiguous south-facing windows with a roof overhang--what the manufacturer calls a "direct gain water wall." Translucent, they absorb and store solar energy while transmitting natural daylight. There are daily wide temperature variations here in Albuquerque throughout the year, which are tempered by the water in the tubes--in the summer and winter, they store the sun's energy during the day and give it off slowly at night, minimizing variations between day and night temperatures and the need for artificial heating and cooling....The tubes also temper the view. Natural light comes through, but the view to my neighbor's not-very-attractive carport is diffused while the trees beyond are visible above them.

When we bought the tubes second-hand, they had never been used. New, the five-foot tall, 18"-diameter tubes cost $174 each. They come in four standard sizes, from four feet to ten feet tall.

I love the way they look and the way they soften what can be pretty harsh light in the southwest. Adding the element of water and the tubular forms bring a quality into the space that contrasts beautifully with the angularity of the walls and ceilings.

The Solar Components Corporation website offers a number of other solar products worth exploring.