I agree with the statement of: INSULATE, it’s the easiest way to gain the most. The passivehouse homes prove this.

I also agree with window covering point. Using thermal curtains that are affixed by magnets will cut down on heat loss, and it can be done pretty cheaply. The most disappointing 2 things in the building industry in my life(42 years) are windows and doors. Seeing an energy efficient home and all the meticulous work that went into, with the same old energy losers for doors and windows really irks me. There was a good show on the Discovery-Science channel around new year’s called Ecolopolis. There was a guy on there that was trying to develop a replacement for window glass using allurgen? material that NASA uses for insulation on spacecraft. No conductivity of either hot or cold temps, and was fairly transparent. The big problem is that it is very brittle.

One last thing, there are some nice boiler systems that are fueled by bio-mass. Wood pellets, corn, and even oats. Oats sounds pretty reasonable because of the cheap price and the fact it’s not a food grain per se, and isn’t fed to food chain animals(cows or pigs)but mostly to horses.

First, where you are, PGW is capable of delivering what you need to power a Rinnai or Bosch or Takagachi unit that modulates between 40,000 and 120,000 Btu hours. If this were not the case a 120K boiler in a large home would die. Because of your square footage and your expected occupancy of 3 people with perhaps a max capacity of 6 people overnite in sleeping bags or on futons a simple low end gas unit would function without challenge with an EF of .85 to .91 as compared with a storage unit with an EF of .56 to .61.

We function here with three people in a duplex using 4100 gallons of water a month which breaks down to 45 gallons per person a day, or 1/2 of the 90 gallons a day used to size septic systems. We presently do this without graywater through correct placement of good shower heads, quality aerators, frontload Whirlpool duet sport washing machine/dryer combos, and a quality Danby dishwasher with water management build in. Your Hot water load can only be as large as the largest gpm of the components which operate downline from the heater! The heater must be matched to demand. GPM Demand can select the heater for you.

While there are those as above who will decry the world natural gas market as suspect, vehicles play an equal part (google Quads 2006 EIA) in the world condition. We will be forced to bring vehicles onto the grid to recharge them in the next 10 years, placing pressure on the grid and creating a demand for microproduction on eveyone. This is why the state and the feds are now reincentivizing existing home efficiency and tying it to solar rebates.

At present rates UNCLE SAM can deliver to you a $2K tax credit for installing an evacuated tube solar hot water heater (NO DRAINBACK IN THIS LATTITUDE!), and Uncle Ed can deliver you $1K to 1.5K. Average cost on an existing home would be $7K. In new construction kill it by 20%, leaving you at 5600 less 3500. If you used it to fill two tanks, one for hot water and one for heat, you could negate your heating bill except for DEC 15 to Mar 15.

All these difficult decisions aside, your obvious weaknesses in a REMRATE model are in windows and doors. As a LOW BUCK approach to managing fenestration loss, I prefer built in window treatments with a built in ceiling on the treatment to block room heat from leaving (remember the first law of thermodynamics?) and to capture heat before it arrives in a conditioned space. Even with windows at say .30 U value, when converted to an R value you arrive at 3.33. When you add an appropriate treatment you can TRIPLE the R value of the opening, drastically affecting the effect of the opening on the whole. My point here is that in modeling, where windows (even in passive solar conditions) often create more loss than a .56 to .61 hot water heater uses in a year.

Need hot water? use whatever current water heater you have allready and simply add a solar drain back system to it. It has been designed so anyone can hook it up. its easy and comparitivly cheap. Another route to try would be a wood fired boiler. with the newer triple pass designs that are out now they cannot be beat for the eco conscious person. oh, geothermal can heat both domestic and space heating water if its sized right. As was stated earlier by one of you (which was the best sentence I read on this site so far) INSULATE!
There is nothing more important than haveing a well insulated draft free home. consider even spray foam! If your feeling extra crunchy you can evan get 99.8% organic spray foam called Biobased 1401 which uses water as the propellent medium.

After looking at Seisco figures we decided it was possible to pair the seisco with a solar water collector, a tank with TWO heat exchangers, and, TWO sets of tubes in our basement floor: one set of tubes to heat the mass, and one set of tubes to draw heat from the floor, reducing the use of the electric heater considerably (in our crusty makeshift model).

The Scheme works like this. The basement floor is not treated as part of a living space: it is seen as part of the HVAC system. Normally a radiant floor heated to 105 degrees max and preferred at 97.5 The floor is normally engineered to take in 120 degree water and drop about 20 degrees as it goes through floor loop. So in our model we hook up one exchanger in the solar hot water tank to one set of tubes with a 10K sensor and a pump. the tank sensor is set at 130 degrees and forms an “and” gate with the floor sensor, if the floor is less than 105 degrees. In this instance, the pump pushes water out to the floor and loses its heat in the concrete, in effect, extending the size of your hot water storage for the cost of a second heat excahnge coil, a pump and some extra HePEX. When the floor reaches 105 degrees OR the tank temperature drops below what you want for your domestic hot water temp (115), the pump shuts off.

Then, on the heater side (or so our theory goes), when the thermostat calls for heat, the first thing the system does BEFORE THE HEATER IS TURNED ON is expose all radiant surfaces in the system to the heated water in the second loop in the concrete. This happens only if it is higher in temp than a sensor at the intake side of the electric heater. In this fashion, the water rolling through the concrete floor loop gives off its heat when it mixes with water from the other loops. When the pad drops to 97.5 in heat, the pad loop closes.

One of the possibilities here is to “overheat” the basement floor up to as much as 110 degrees if it is appropriately segregated from the living space. In this way, more heat is stored in it. In the event it was a living space, you could lay sleepers and another floor on top of them and drop a simple vertical duct from the floor leves in the living space down to the pad surface and use the rising heat to advantage and to create some degree of convection in the house.

Where I am with this is I am confident on the size of the seisco heater, and have controls down. I have yet to ask my superfriend, Brendan O’Riordan, a GSK engineer and a night student at Drexel Architecture, to sit with me through the calculations for the solar loop: We need to get sizing for the collector, tank, exchangers, and floor tubing, relative to the volume of the rest of the system. We also need to look at the optional duct and or fan drawing heat from the pad.

As regards gas boilers, hands down Bederus is the best of the best I have used. I understand it does not apply here, however, you might look at what features they offer in the hope of finding someone else who can give you the bang for the buck you need.

I also heard the comment about having enough roof space and wonder if the house is structurally capable of handling a roof deck, with an eye toward creating a solar panel canopy over a future deck.

At the moment, though, I have to go make money. So I leave you all to ponder choices. I am sure you will find a good combination

Ok, I gotta go make some money

This might be a nice supplement for heating.
I agree about radiant. It really is a great system. I just wish there was a good heat pump setup for heating water for the radiant loops. Geothermal does a good job for low temperature radiant, but that’s no in the cards for a low-budget project. Ultimately, the solution you’ve picked seems like the best choice given the constraints.

At this point we are all married to the idea of radiant heat, both for the efficiency and the marketability of it. I have cold concrete floors with forced air and would love to have radiant if possible. This is seen as a premium feature in Philly, so the fact that we can pull it off affordably is a no-brainer for us.

Thanks again, and I look forward to more of your comments in the future.

Electric storage water heaters are quite efficient, up to an energy factor of 0.95, which is vastly better than any of the (affordable) gas water heaters. Also remember the installation cost differential. Electric heaters are plug and play. Gas requires flue and combustion air vent installation

On solar hot water- I often hear the comment about what to do with excess summer production. Note that the locations where solar thermal is most popular are hot, sunny climates, where they likely have excess production year round. You just have to design the system properly.

Also, as noted by another poster, solar thermal can be very cheap and effective. Another group in Philly showed the efficacy and costs of different designs. I can’t find the link at the moment, but was talking with Nick Pine who has all sorts of ideas on low-budget/practical solutions, and he referred me to that project.

Was talking with PECO the other day. Their electric is 70% nuke. Whether you like it or not, that greatly reduces the CO2 in the comparisons. Also, for a cost analysis, remember that if you heat with electric, you get RH discounted rate in winter, which is only 7.029 cents/kwh after the initial 600kwh used. This makes even electric resistance heating much more affordable, but still not as cheap as NG at today’s rates.

For the long term, you’d be better off with an efficient heat pump in a small structure like this. A decent one costs only 2/3 as much to run as NG, but still doesn’t resolve your need for hot water. And, the first cost would be several times that of a simple electric water heater.

If I were doing this for my own projects, with your constraints, I would go with home-made solar space heaters supplemented by cheap electric baseboard heaters and a Whirlpool EnergySmart electric water heater. When my budget allowed it, I’d add solar hot water.
If I didn’t have as strict a budget, I’d get a high efficiency, two stage heat pump, plus use good passive solar design and solar space and water heating.