Druid Zoning

Denver's new zoning code is on track for approval in February, after about five years of hard work. In the last few days, many folks have rallied in support of "passive solar access". It's a big enough groundswell that it has gotten everyone's (except the Mayor's) attention for the moment.

At first blush, it sounds like a great idea, but only one person has attempted to quantify what it really would require in terms of zoning.

Bernadette Kelly of MOA describes "block sensitive height limits" as a solution. Similar to how the context sensitive front setback is calculated, it would regulate building heights based on the current status of what's on the ground. She cites an English "right to light" law that derives from the Druid civilization. To paraphrase: "if a structure has had access to the sun for at least 20 years, it is illegal to ever block the sun from that structure".

It does solve the problem, would satisfy most solar advocates, but it is a bit impractical to implement, and would greatly diminish your neighbor's current property rights. (Full disclosure: the author is a solar advocate, but hopes to profit from the ability to increase density in transit neighborhoods)

It's doubtful that this proposal will see the light of day in this version of the zoning code, but it's not without merit. Some neighborhoods of one story homes and large side setbacks may want to STAY neighborhoods of one story homes and large side setbacks, and there are no tools in Zoning Code draft 3 to help preserve that context. Two story homes have always been allowed everywhere in Denver, and CPD has thus far refused to change that.

The Rubber is Starting to Meet the Road for Smart Grid City

The Smart Grid pilot project in Boulder is now well enough along for the peak period re-pricing to be released.

http://www.dailycamera.com/schoolchoice/ci_13732272

This article missed answering an obvious question:

If you own a PV system that contributes to the grid during peak periods, will Xcel credit you at the higher peak retail rate?

My guess is yes. It's only fair. But this issue should be openly addressed soon because it will make your PV system pay off much quicker

LED Lighting Update

Yes, CFL's suck.

So, we've been waiting for bright, affordable LED lighting to become available. Sam's Club has recently introduced 1.5W LED bulbs for $5 each. I believe Xcel energy is subsidizing some of this cost based on a flyer displayed in the aisle. If anyone knows more about that, please post a comment.

Anyway, 1.5W is only producing about 78 lumens, which means you'll need roughly six times the number of bulbs more than "normal". This is a daunting problem that will keep most folks out of the LED replacement business until a market solution or even brighter bulbs are introduced.

In the meantime, we developed a hack using "Medusa" floorlamps, which can be found for as little as $20 and will convert a standard octagon ceiling box into a fixture with five medium base openings. An added bonus is that you can direct the lighting to where you need it.

Let's say you have rentals or are doing fix and flips. You already know that fluorescent lighting and CFL conversions do NOT add value, even though operational cost is lower. The light quality of LED's and even lower operational costs SHOULD add value to your project. Don't be cheap - the $20 marginal cost per fixture is only a couple hundred $ for a house.

Edit: photo posted above

Dual Flush Toilets Now Affordable

If you've been too cheap (like me) to get a Toto or Caroma Dual Flush Toilet, now you have no more excuses. For a long time, these toilets have averaged $400, making them difficult to pay for themselves.

Sam's Club is stocking the Alexis HET (high efficiency toilet) 1.1 gpf liquid, 1.6 gpf solid dual flush toilet for $99.

Since Denver Water is giving a $125 rebate for them, this is a real no-brainer.

Go get one while they still have 'em.

Solar Shading Cont'd

The classic all-aluminum rollup design is my personal favorite solution for exterior window shades. They're economical, ( $150-$300), self-storing, accessible from inside the home, and infinitely adjustable depending on the season or your whims.

They can be ordered at Home Depot or online at http://www.screen-house.com/awnings_rollup_aluminum.htm

Sun Control - One of the Solutions to Summertime Overheating

This topic is old news for those of you with those big, west-facing-mountain-view windows. They create an inferno for you in the summer. You may have even spent thousands on beautiful floor to ceiling blinds to shut out the sun.

However, unless the shades are physically outside the window, they are relatively ineffective. Once the sunshine comes in the window, it stays inside as heat.

So the shades must be on the outside.

The easiest, quickest, and least expensive way to install an exterior window shade without completely ruining the view just might be from Screenmobile. They are a national franchise, and I've used the local branch often for conventional screen replacement, and found them to be a good solution for an annoying problem.

Heat Pump Hot Water Heater

So, you're trying to decide how to heat the domestic hot water in the zero energy house you are designing for Denver.

Solar hot water heaters are an excellent choice. However, the logistics of a solar thermal installation are daunting compared to a typical appliance installation.

A logistically easier solution is to use a heat pump water heater (HPWH) in conjunction with PV solar.

Rheem has just released a new nice-looking unit.

The jury is still out as to which configuration will be best. Recent test results and common sense are beginning to favor HPWH with PV. The reasons for this are that solar DHW is insufficient and inefficient in the winter, and underutilized in the summer. A grid-tied PV system has the advantage of constant efficiency and 100% utilization year round. In addition, large PV cost reductions are coming, but none are expected in solar thermal. State-of-the-art solar thermal collectors still use supply-restricted copper, aluminum, and glass. The labor content of solar thermal installations is also quite high.

Some puzzles remain with the implementation of HPWH systems. Per the manufacturer's recommendations: "Because the heat pump’s exhaust air is cooler than the surrounding atmosphere, these water heaters generally do not belong in or near busy living areas of the home." Since they pull the heat out of the surrounding air, a small, airtight mechanical room isn't the best place for it either.

Discussion of HPWH locations:

1. The garage. A new, well insulated garage might work. An uninsulated garage slab gives off enough low temperature free geothermal heat* to prevent freezing of the pipes to the heater. There are at least two problems with the garage, however: 1. In summer, the HPWH gives off cold air that would be more desirable inside the living space than in the garage. Ducting air from the garage to the house is a CO hazard, and not recommended. 2. If the (insulated) garage door is inadvertently left open in the winter for an extended period, the water lines to the HPWH are at risk of freezing.

2. Mechanical room with forced ventilation. The control scheme and ducting layout for this ventilation can get complicated and costly.

3. Basement. This is where you usually find the water heater in new construction, and will work just fine if you don't mind a cold basement in the winter. If you finish the basement and add heat to it, that heating system will be feeding the HPWH the heat it needs, and this will spoil the overall efficiency of your system.

"The House as a System" philosophy of home design will get a real workout on this one. Please enter a comment if you've heard of any other solutions.

*A perimeter insulated slab in an insulated garage gives off 5-15 Btu/hr/ft2, based on preliminary research. This is a great match for a 7000 btuh HPWH.