Energy Calculations

[frwillia]

Originally posted by Tim O'Donnell
a lot of energy could be saved, simply if so many did not think they needed a 10,000 sf 'cottage' w/10-12' ceilings....

Right on.

We purposely kept the ceilings to 8' (basement is 9') in our new house specifically to be able to keep it warm with out having to heat so much volume. All our houses in CA had vaulted ceilings - the last one had a living/dining room ceiling that was almost two stories high (16'). Even in the high desert (at 3,000') it was hard to keep that room feeling warm when standing on the floor in the winter. However, we bought it for the property, access to hundreds of miles of riding trails, barn, and riding arena, and the location, the house just happened to be what was there, and it was otherwise "acceptable", so we lived with it.

Fitch

[mcqueenhomes]

I agree with Tim also. A super-high ceiling may be impressive but not necessarily comfortable. That's the sort of thing best left for the county courthouse. Once I knew a man who paid big money for a three-bedroom townhouse with a two story living room. The living room was only like 14' square. It was like sitting in a chimney with windows.

I like mostly 8' (or sometimes 9') ceilings first floor and 8' second floor. Also I try to size and shape the rooms for the furniture and function they contain. I also prefer to keep the house 3000 sq.ft. or less.

A lot of times we could save a lot of energy by using porches and trees like they did in the old days. I saw on TV a show where they featured a 150 year old southern house with a natural cooling/ventilation system. It was reported to be remarkably effective despite the lack of technology.

A reasonably good way to do a vaulted ceiling is the way it used to be done in a manufactured home. The vault would start at around 7' and go up to 9'. It gave the sense of a vaulted space but was easier to heat.

[VHampton]

I live on Long island which has the highest utility rates in the country. One *cottage* I know of... with over twenty thousand feet of living, pool house, guest house, fountains and reflecting pond has an average electric bill of $4,000-5,000 a month...depending on cooling season.

How's that for green living.

[mcqueenhomes]

WOW. For that you could almost buy a town. That's probably enough square footage to equal every house on one whole block of my neighborhood put together.

[VHampton]

It's pretty incredible when you can see the footprint of your own home inside the "Living Room" area on the floor plans.

[mcqueenhomes]

I worked on a house with a rec room over a garage like that once. Of course it ain't that hard to fit 24'x37' into a very large room.

[FWD]

"properly set up the systems switch seamlessly and you do not even notice that it is being controlled...last winter I spent less that $2 a day for heat (this is in northern MN, farther north than most Canadians live"

Tim,
Imagine what you'd save if you just wore a coat!!

Dan
(born & raised in Mpls/St Paul)

[ChasAnderson]

I use ResCheck for MEC's and Ductaputer software to help guide duct sizing and balancing. I seem to do a better job at it than most Mechanical Subs because my plans always get through Mech plan review. Of coarse I am indeminified and the Mech Contractor is responsible for final installation. I thiink most Mechanical subs are just too busy to design until they know they have the job, and they just don't want to put out any effort until they see green. I can understand that, but I ussually need to get off first base so I have self taught myself. The total cost of this above software is $15. I love to be self serving as it enables me to produce plans faster and with less hassle.

[Alex-Berkeley]

- Originally posted by frwillia -
"I confess I don't understand that last sentence. What does it mean? I have to redesign and re-optimize the house for energy use every time I change its orientation on a lot in a subdivision? "

Yes, that's what it means ... however, we are allowed a simpler approach to subdivision's energy performance modelling ... we do a computer simulation of the house facing north-south-east-west ... if the house complies in all 4 orientations, it may be built anywhere in the subdivsion. However, this assures that only the most stringently efficient version is permitted to be built. Typically, the poorest performing orientation for a tract house is with the back facing west ... that's where the sliding glass doors are and most of the bedroom egress windows and virtually no overhangs or other shading features.

"...Are you talking about time of day electricity pricing?..."

Absolutely ... Up until this October, we have assumed that due to generating and transmission losses, the penalty for trying to use Electric Resistance heating was a factor of 3x less efficient than Natural Gas used on site. This did not account for the fact that there was a higher demand for electricity during afternoon peaks. With time-of-day electricity pricing (TDV), that multiplier could be as much as 25x in the afternoons.

"What are you using as an economic model to justify higher initial cost than the MEC would cause?....
There would seem to be a lot of variables in this process that are pure guess work. Much of the MEC is based on reasonable return on investment. What is what you propose based on?"

The California Energy Standards are based on the lowest life-cycle cost analysis of installed components. In other words, no energy czar simply says "thou shalt use R38 ceiling insulation", etc. Since 1983, there have been dozens of monitoring and evaluation studies to support (or debunk) conservation measures. The field verified performance of the measures is what makes the standards politically supportable even by Gov. Arnold. Every change to our standards is evaluated for reasonable return on investment by thousands of computer runs (I know, I've reviewed many!)

We are also instituting extensive energy installation inspections via Home Energy Rating System (HERS, google it) to address the follow through in the field.

States using MEC-based energy standards are only starting to deal with building energy conservation. Future economic growth will depend on doing better, and I know ASHRAE is working on influencing this.

[frwillia]

Originally posted by Alex-Berkeley
[BThe California Energy Standards are based on the lowest life-cycle cost analysis of installed components. [/B]

Specifically:

What are the economic assumptions upon which this analysis is based? Future interest rate, future cost of each type of energy, etc., life cycle cost of materials for each technology (including future disposal cost)?

Fitch

[Alex-Berkeley]

What are the economic assumptions upon which this analysis is based? Future interest rate, future cost of each type of energy, etc., life cycle cost of materials for each technology (including future disposal cost)?

Every 3 years, the Code is revised and the economic assumptions are revisited based upon the input of all the players ... builders, utility companies, architects, energy specialists, "lobbyists" ... it's pretty dynamic and done in open public hearings. I think the only thing that I haven't seen represented in these hearings are the Greens.

The utility companies have the biggest say and the most expert opinion on future costs ... as stake holders, they have critical interest in managing future loads, not politics or ideology. The payback criteria is typically 5-8 years.

Here's how the modelling works for,say, wall insulation ... we run a computer simulation of a statistically average house plan (which has changed over the years as the market has changed) for all 16 CA climate zones varying only the wall insulation (R11, R13, R15, R19, etc.) ... the point at which the payback curve flattens or drops below the payback target, it is considered too stringent. And yes, the cost model includes the difference in framing depth and labor.

Want details and a lot good information? try this link:

http://www.energy.ca.gov/title24/index.html

[frwillia]

[i]
Want details and a lot good information? try this link:

[/B]

Thanks. The link didn't work, but a google search turned up some good information related to title 24. I downloaded a bunch of it.

Not much of any way to find out what the impact would be here though - all the title 24 Sw seems to be CA specific since that's the only market for it.

Thanks for the heads up on where things might be headed. Hopefully it works better than the state electrical energy strategies worked, and isn't as ill advised as the mandated gasoline addatives.

I'm still a bit skeptical about all the payback calculations - there are necessarily a lot of guesses involved in setting up any forecast of future events. The number of times folks guess right about things other than self fufilling prophesies, especially over time frames approaching 5 years (less than the payback window), is remarkably few.

I did, in a way, bet on the future when I spent the extra money to install a good closed loop geothermal heat pump with two 300' wells. I used payback assumptions related to today's fuel cost. If fuel goes up faster than electricity prices, (likely), then my payback time gets shorter. If they march in lock step it stays the same. The only way I come out behind is if residential electricity cost goes up faster than fuel prices (unlikely).

I also find my self disagreeing with your assumption about the purity of the electric utility company motives and their ability to make recommendations devoid of agenda - their agenda. They will make recommendations that optimize their bottom line. Anybody who thinks they won't is seriously misguided. The hope, and its only a hope, is that the recommendations that optimize their bottom line are also in the best interest of the residential home owner.

Fitch

[Alex-Berkeley]

Not much of any way to find out what the impact would be here though - all the title 24 Sw seems to be CA specific since that's the only market for it

Actually, both EnergyPro & Micropas can provide weather files for many states, cities, and provinces throughout the US & Canada.

Why bother? Well, for serious energy modelers, Micropas simulation data can be monitored monthly/daily/hourly to check sensitivity to energy design decisions. Overhangs, fins, thermal mass, ventilation (and more) can be evaluated for effectiveness.

EnergyPro provides detailed life cycle costing tools which can be adjusted to virtually any utility rate model.

Both programs do load calculations, and EnergyPro also does Non-residential models (utililzing the DOE2 engines) which allows us to tradeoff between Envelope, Lighting, and Mechanical systems. It also cross-references to LEEDs points.

Only the California market? Don't look now, but there are quite a few energy design and mangement companies, research groups, university AE departments, and state agencies evaluating the implimentation of performance based standards... and the tools are ready. (We have company offices in two states already ... 3,000 miles apart offering energy design services.)

I spent the extra money to install a good closed loop geothermal heat pump

Who's equipment? Fan-coil distribution or radiant? Heat & Cool? Sounds interesting ... I've used Canadian units at some ski resorts we've worked on.

Someone has just come to market with a residential scale thermal storage unit which makes ice during the off-peak hours. I'm not ready to use them yet, but I'm looking.

[frwillia]

Originally posted by Alex-Berkeley
Both programs do load calculations, and EnergyPro also does Non-residential models (utililzing the DOE2 engines) which allows us to tradeoff between Envelope, Lighting, and Mechanical systems. It also cross-references to LEEDs points.

I downloaded e-QUEST last night. Haven't had time to install it or read any of the bunch of data that was on the same WEB site. It's free. Right now I don't have time to do much with it, but after we move in in September (and I'm not spending 8 hours a day working on the house and 5 hours a day working on CA) I'll look forward to exploring it.

Who's equipment? Fan-coil distribution or radiant? Heat & Cool? Sounds interesting ... I've used Canadian units at some ski resorts we've worked on. [/B]

ClimateMaster Tranquility 27 model number TT*049 set up for closed loop operation on two 300' wells. Two speed compressor, two speed fan, 4 zone Honeywell controller. Each zone is controlled by a damper and its own thermostat.

If I set all the thermostats to 70F, the house will stabilize at 71 +/- 1F. The basement needs heat (it wants to be around 64F this time of year), the bonus room over the garage needs the most cooling. The unit will cool the bonus room for a while, the pump stops, the blower runs to purge the ducts, then the dampers switch, the pump restarts and it goes into heating mode to warm up the basement. It switches to what ever mode is needed.

Right now, since the house is still under construction, I have turned the basement zone off.

I'm looking forward to spending some time studying this to see what's going on. Who knows, maybe there is an advantage in there someplace for the builder I do most of my designing for. He does mostly starter houses, but if they can be made more energy efficient with out increasing the cost, that would be a feature. These are houses for people who worry about price changes of a couple of hundred bux. They are good people who really want a house but almost have to skip a meal a day to get in one.

Be good for them if the energy cost can be reduced with out increasing their mortgage.

Fitch