Elementalbuilding

It might be surprising to you that residential space and water heating account for more than 50% of the average household energy and produce more greenhouse gases than the average car. For this reason, Elemental Buildings is investing a good amount of its resources into wall and window insulation to reduce the amount of energy required to heat and cool a home. However, an equally important consideration is choosing the heating system to heat the home.

Recently, I wrote a letter to the editors of Environmental Building News regarding the use of heat pumps in residential homes.  While heat pumps have gained great popularity as ‘green’ sources of heating and cooling the home, I am convinced that they aren’t the most efficient method of heating. I thought I’d take this opportunity to expand upon this letter and explain why I’m choosing to go with natural gas for water and ambient heat.

Heat pumps can be used as hot water heaters, or to heat the ambient air inside your home during winter. Some people call it ‘free heat from the ground’, others say you are simply moving (pumping) heat from one place to another.  In some ways this is true. Heat pumps work because all objects, both hot and cold, contain thermal energy. Consequently, you can take the energy out of the cold objects (to make them colder) and give them to the hot objects (to make them hotter). A heat pump is an anti-Robinhood. It steals from the thermally poor and gives to the thermally rich.

It might be easier to think about this in terms of an object you use every day – the air conditioner. An air conditioner cools your house by transferring thermal energy from the air inside your house (in effect slowing down how fast the air molecules zip through the air) to the air outside your house. If you ever stand outside the exhaust from an AC outlet, you can feel how hot the air can get.

Of course it isn’t free to run your air conditioner. An AC unit transfers heat from inside to outside by successively compressing and expanding a gas (what used to be Freon) in a closed loop between the inside and outside of the house. The energetic cost is the amount of electrical energy required to run this closed loop. This electrical energy can be compared to the thermal energy transferred between the inside and outside of the home. This is called the coefficient of performance or COP.

The COP for a heat pump is around 3.5. This means that the heat pump transfers 3.5 kilowatt-hours of heat energy into the home for every kilowatt-hour of electrical energy it uses. Sounds pretty good, huh? Compared to an electrical heater it is. The COP for an electrical heater is less than 1. In an electrical heater, electrical energy is converted directly into thermal energy (by running it through a resistor, for example) with a little bit of wasted energy to create things like light (your electric stove glows when it’s hot, right?). So an electrical heater can transfer less than 1 kilowatt-hour of thermal energy for every kilowatt-hour of electrical energy it takes to run it.

So why not use a heat pump? While it seems incredibly efficient, it really isn’t. A heat pump requires electricity to run and generating electricity is incredibly inefficient. You can’t just ignore the wasted energy and greenhouse gases produced by making electricity. In America, most electricity comes from burning coal. This produces steam, which turns a turbine to generate electricity. Only 30% of the energy from burning coal actually gets converted into electricity; the other 70% is released into the environment as wasted heat . But this heat is exactly what we need! If we burned the fossil fuel in our house, we wouldn’t be wasting the heat into the environment.

This is why it still makes sense to use natural gas to heat your home. If you run the numbers, the greenhouse gases produced to produce the electricity to run heat pumps is higher than the greenhouse gases produced by burning natural gas to heat a house. This ignores the additional energetic costs in digging a large hole in the ground as a heat sink and the extra expense in purchasing the heat pump.

One day it might make more sense to use heat pumps. In England, research is being done to run heat pumps without using electricity (article). Secondly, as we transition to using solar and wind to generate electricity, we will no longer be producing greenhouse gases to make electricity. In some areas of the country where renewable resources are more popular (such the Northwest, where > 50% of electricity is generated by hydroelectric), it makes more sense to use heat pumps. Which brings us back to another point Elemental Building believes in – going green requires local solutions to each problem.

The new open roof- as seen throught the future curtain wall

Work begins on removing the roof to make room for the new steel joists that will support the new second floor addition.

SLowak tosses pieces of the old roof off as the moon looks on

The carnage of Hurricane Slowak

Slowak, Tony, and Bohdan clean up the mess.

A nice article came out in Chicago Architecture Today about the house.

Article

Plus work continues on replacing the old wood/aluminum sided house with brick and on opening up the side of the house for the new glass curtain wall.

The original south exposure with the wood/aluminum porch.

The south exposure with the porch replaced with brick

The opening for the new glass curtain wall (remember we still have a whole floor to add)

Houses of 100 years ago were built with plaster and lathe board.  Eventually plaster, ‘ wet walls’ were replaced with Dry Wall.  During the demo of the 1610 home, literally tons of plaster and lathe are removed from the home.  The plaster is worthless- even as back fill- it’s basically like sand once it breaks down.  99.99999999% of people would say the same about the lathe board.  Though some might grind it into saw dust for animal bedding or others might use it for kindling.  Most however send it to a land-fill.  We however, we chose the path less taken.  We decided to take the very arduous task of turning the lath into laminated lumber.  Despite the exhaustive work, we are quite happy with the results and hope you are too!

Plaster hanging to pieces of Lathe, mid demo

Once the lathe is removed, it’s piled high in the garage:

The pile begins

Mike McGowan assesses the growing mountain

Painstakenly each nail is pounded out of the lathe:

Dan Rusk finding his zen moment

Nate Rusk, after a hard day of pulling nails

Pegger, planing the lathe.

Once planed, the lathe is glued into 6 inch wide, 9 ft long planks.

Then the planks are planed once again.

Katers, hand planing the planks

And after a final pass through the electric planer, we have the final product:

Finished Planks

And somehow after many hours of manual labor, and electricity generated from the sun,

This,

Lathe on the wall

Becomes this:

Finished Book Shelves

Conjuring memories of the works of Gordon Matta-Clark, 1610 is looking very light these days.  No-worries though, no intention of ‘creating by destroying’, we’ll reuse as much of the old brick as possible once the new foundation walls are poured.

Hey where did my face go? Front (East side) of building

Back (West side) of building

one of the several piles of saved bricks

Artur, (a different Artur), knocking mortar off of bricks

Artur, one of the ACT developer/builders crew begins the process of taking down the west wall.  The brick will be re-used in the new brick wall and in filling in gaps of the existing walls after the windows are added.

The beginning of the end, or is it the end of the beginning?

Net-Metering bill from Com-ed

One of the first bills from Com-ed.  It shows we produced 967 KwHours in July and only used 11.  NICE SURPLUS! 

So- what’s the deal with Net-metering?  In Illinois, we buy at 10 cents/KwH and sell at 10 cents/KwH.  Also, if you produce more than you use, you don’t get a check back from Com-Ed.  All you get is to roll the balance forward.  At the end of a year, if you have a credit the slate gets wiped clean and you start all over from scratch.  Also, you pay about $10/month for ‘distribution’ (even though most of my power is generated on site and doesn’t need to be distributed).   So the bottom-line is that in Illinois, you can’t make money on your investment, and it’s really difficult to even break even on it.  Given the fact that we currently have much more demand than supply for renewable energy, it’s sad that things are so stacked in the utility-company’s favor.

What can you do?  The financial deal is simply legislative.  Some states like Wisconsin have progressive policies where you buy at 10 cents but sell at retail rates (currently 25-30 cents).  Countries like Germany and Greece are even more progressive (Greece recently passed law requiring the sell price be set at 55 cents/KwH).  You can become active in the cause by writing your state legislators and asking them to support FIT/REP (Feed In Tariffs/Renewable Energy Payments) legislation.  More information can be found at the Alliance for Renewable Energy.