Saturday, June 7, 2014

Is the "Sharing Economy" a Green Strategy for Denver?

When it comes to housing, airbnb is the most important player in the sharing economy.

Airbnb is a very useful tool to help a building owner eke more money out of his investment. More income means his investment is more sustainable.  The visitors and tourists that use his accommodation will spend money in the neighborhood. That makes the local businesses more sustainable.

Having thousands of airbnb hosts makes a growing city more sustainable because it means that fewer new hotels need to be built. New hotels place a large added burden on the utility infrastructure.

Some cities are resisting the new realities of the sharing economy, and are hampering its growth through unnecessary regulation.

For many years, Denver's zoning law has prohibited homeowners from having lease periods of less than 30 days.  This law has been challenged in Park Hill, but the law prevailed.

Today, Denver's neighborhood leaders tend to be the type of people that want to "preserve neighborhood character".   They do not like short term rentals.  City Council President Mary Beth Susman understands the "sharing economy" and has begun the discussion.   Stay tuned.

The Future of Residential Heat Recovery is Ductless

I just took ownership of the first ERV to be sold at Home Depot
Price $431
Extra stuff I learned about it once I got my hands on it:
1. The 16cfm mode, medium, (perfect for a 2 person bedroom) is only 0.3 sones at 4 watts. Almost inaudible.
2. Low speed is 8cfm (the one person setting) is 0.1 sones which is TOTALLY inaudible.
3. It can cycle on humidity if desired. That is, it will come on when the humidity reaches 45%RH (low), 55% (medium), or 65% (high). If the indoor humidity exceeds the set point, the unit is switched to high speed.  If the indoor humidity is within 5% of the set point, the unit operates at medium. If humidity is 5% below the set point, the unit switches to minimum speed.  This sounds like a reasonable control strategy for winter, but in the dry Mountain West, it would always be on low speed.  It sounds like the wrong control strategy for summer.
4. It pretty much is a ripoff of the Lunos design, but I don't know if either design is patented anyway.
It's not synchronized like the Lunos but I believe synchronization is unnecessary, and actually reduces the total house airflow.
5. The US distributor, Zoltan, will give a quantity discount, which gets it down to a price I can justify in new construction spec homes and rentals.  With a name like that, he knows all about predicting the future
6. The exterior vent cover is an elaborate, good looking, bomb proof fabrication of stainless steel.

7.  When the unit is off, it has a high quality, very tight powered plastic damper.

In my opinion, if the bedroom doors are left open except at bedtime, Fick's Law of Diffusion will ensure that fresh air will reach the rest of the house.   (The average speed of an air molecule flying around the room is 500m/s)  That means a three bedroom house may only need 3 total units.

Other important things that should be mentioned:
A.  Perfect zoning
B  Dead simple commissioning.
C.  Wires are easier to run than ducts.
D.  More total holes in the walls. (Bad)
E.  Inherent frost protection.