Summary

2/5/2008

Only 15 households around Greater Cincinnati Ohio volunteered to participate in my 2006 survey. Table 1 (below) shows raw data and responses plus calculated performance values. Energy from all conventional sources was converted to comparable BTU content, then subjected to calculations and comparisons. Average CO2 emissions per kBTU of energy and demand per person are both shown, as well as water purchased per person per day. In all categories, lowest values are shown in green cells, highest values in pink cells. Table 2 (further below) shows energy efficiency (EE) and alternate energy (AE) features reported in "EE-AE Measures" column.

For the first time, I also show how each household's per-sf and per-person usage compares with the national average, based on US-DOE/EIA's 2001 data. (See table CE1-5.2u in "Outcomes to Aim For" showing US average energy use among all households as 46.7 kBTU per sf and 36.0 mBTU per person.) Compared to these, the average annual energy usage per-sf in this survey was 39.4 kBTU, about 16% less than national average. Average annual energy usage per person in this survey was 31.7 mBTU, about 12% less than national average.

One might think that a "most efficient" household would have lowest energy cost overall, lowest energy cost or usage per square foot (sf) of conditioned space, and lowest energy cost and usage per person. One might also presume that if energy usage is lowest or if an energy supply has lowest CO2 emissions per BTU, CO2 emissions per person would also be lowest. Unfortunately, none of these assumptions is true most of the time. Certain households do tend to emerge as seeming "winners" across several categories, as can be seen even in this small sample.

Only households 3, 4 and 6 scored SUPER in both per-sf and per-person categories. Households #3 and #6 are in a new super-efficient houses designed by me, so might be expected to perform well. But household #4 achieved lowest energy and water usage, lowest energy cost and per-person cost, also lowest CO2 per person, all despite being in an older home with fewer EE/RE features. Low energy usage was probably due to more stringent management and conservation practices. Lower CO2 in #4 was due to lower electricity usage and use of natural gas for heating, while #3 does not even have natural gas. Household #11 achieved the least energy usage per sf and was 3rd-best in energy cost per sf, despite averaging the least energy content (35 kBTU) per dollar spent on energy. Household #8 got the most energy per dollar (71 kBTU) and used the most energy per sf. Household #12 (mine) reported the most EE/RE features and achieved the lowest per-sf annual energy cost for 2006, due both to lots of EE/RE and firewood which costs less in rural areas than in urban and suburban areas. But #12 did not achieve best performance in any other categories. Household #10 shows the difficulty of achieving good energy performance when only one occupant is in an average single-family home, even when it is a small home. It is also interesting to note that the energy mix for household #10 had one-third as much CO2 content as that of household #11, yet both households achieved the same highest CO2 emissions per person.

Thanks to all who participated in this survey!

Table 1. Household Energy Data

	Occupants	Flr SF	Conventional Energy Types	EE-AE Measures	County STATE	Total Annual Energy Usage					Usage per SF		Usage per SF & Climate		Usage per Person		Usage per Person & Climate		Energy-Related CO2 Emissions		Daily Water Use
	Occupants	Flr SF	Conventional Energy Types	EE-AE Measures	County STATE	Total Annual Energy Usage					Usage per SF		Usage per SF & Climate		Usage per Person		Usage per Person & Climate		Energy-Related CO2 Emissions		Daily Water Use
						$	$/person	$/sf	kBtu	kBtu/$	kBtu/sf	Comp w/ NatAvg01	Btu/sf-dd	Rating	MBtu/p	Comp w/ NatAvg01	kBtu/p-dd	Rating	Avg Lbs per kBTU	Daily Lbs per person	Gal/Person
1	2	1980	Elec, Ngas	CDGHI	Hamilton OH	1532.64	766.32	0.77	69281	45	35.0	75%	6.36	Efficient	34.6	96%	6.29	Efficient	0.34	32
2	6	3777	Elec, Ngas, Wood	BEFIST	Hamilton OH	2206.00	367.67	0.58	131959	60	34.9	75%	6.35	Efficient	22.0	61%	4.00	Efficient	0.28	17	78
3	2	2100	Elec, Pellets	ADEFGHIPST	Dearborn IN	1088.70	544.35	0.52	42974	39	20.5	44%	3.72	Super	21.5	60%	3.90	Super	0.39	23	31
4	4	1200	Elec, Ngas	CDFHILN	Hamilton OH	696.51	174.13	0.58	30990	44	25.8	55%	4.69	Super	7.7	21%	1.41	Super	0.26	5	24
5	2	2622	Elec	EFLT	Hamilton OH	1353.98	676.99	0.52	50353	37	19.2	41%	3.49	Super	25.2	70%	4.57	Efficient	0.62	42	70
6	4	3058	Elec, Ngas	BEFGHPST	Hamilton OH	1377.39	344.35	0.45	60102	44	19.7	42%	3.57	Super	15.0	42%	2.73	Super	0.34	14	37
7	2	3456	Elec, Ngas, Kerosene	EFH	Hamilton OH	1418.60	709.30	0.41	73788	52	21.4	46%	3.88	Super	36.9	103%	6.70	Efficient	0.27	27	99
8	4	1704	Elec, Ngas, Wood	EFP	Hamilton OH	2230.23	557.56	1.31	158104	71	92.8	199%	16.85	Inefficient	39.5	110%	7.18	Efficient	0.24	26	57
9	6	2053	Elec, Ngas	EFHL	Hamilton OH	3446.62	574.44	1.68	178344	52	86.9	186%	15.78	Inefficient	29.7	82%	5.40	Efficient	0.34	28
10	1	975	Elec, LP, Wood	DEHNW	Clermont OH	1791.92	1791.92	1.84	83646	47	85.8	184%	15.58	Inefficient	83.6	232%	15.19	Inefficient	0.21	49	24
11	2	4000	Elec, Wood	BEFGHST	Butler OH	1710.00	855.00	0.43	60416	35	15.1	32%	2.74	Super	30.2	84%	5.49	Efficient	0.59	49	85
12	2	2100	Elec, Wood	ABCEFHILPSTV	Kenton KY	775.65	387.83	0.37	45605	59	21.7	47%	3.94	Super	22.8	63%	4.14	Efficient	0.36	23	41
13	2	2750	Elec, Wood	BEGHPSTW	Hamilton OH	1681.81	840.91	0.61	80313	48	29.2	63%	5.31	Efficient	40.2	112%	7.29	Efficient	0.42	47
14	3	2025	Elec, Wood	FHILPA	Hamilton OH	1669.00	556.33	0.82	104058	62	51.4	110%	9.33	Average	34.7	96%	6.30	Efficient	0.23	22
15	3	3000	Elec, Oil	BDFL	Warren OH	2252.04	750.68	0.75	95835	43	31.9	68%	5.80	Efficient	31.9	89%	5.80	Efficient	0.44	38	49
Avg	2.9	2410				1682.07	659.85	0.78	84384	49	39.4	84%	7.16		31.7	88%	5.76		0.36	30	46

Table 2. EE/AE: Energy Efficiency & Alternate Energy Features

A	Active solar water and/or air heating)	L	Landscape for shade, food, windbreak, waste processing, storage, etc
B	Bermed Living Spaces	N	No Furnace or AC, either or both
C	No clothes dryer and/or frequent use of a clothesline	P	Passive solar for daylighting, winter heating, summer cooling
D	No dishwasher and/or very infrequent use	S	Superinsulated (150% of code level or higher)
E	Efficient Appliances	T	Airtightened
F	Mostly fluorescent and/or LED lamps	U	Underground Roof & Walls
G	Mostly Superior Windows R-3 or better overall, low air leakage (< 0.10 cfm/sf)	V	PVs (solar electricity, whether or not utility-grid-connected
H	Efficient HVAC System	W	Home Water Supply (roof-fed, well, etc.)
I	Income-produced at/from home

Ratings of super, efficient, average and inefficient were assigned to each of the two climate-adjusted energy use performance categories based on the following scales:

Btu/sf-dd		kBtu/p-dd
0-5 Super		0-3.95 Super
5-10 Efficient		3.96-7.90 Efficient
10-15 Average		7.91-11.86 Average
15- Inefficient		11.87- Inefficient

Read in my 2001 and 2002 survey reports for more detailed discussion of how this ratings scale developed. To understand and study my surveys and process, it's best to read them all, starting with the introduction. Each builds on previous work and commentary!

John F. Robbins, CEM CSDP

3519 Moffett Road

Morningview, KY 41063-8748

Phone: (859) 363-0376

E-mail: johnfrobbins@insightbb.com