Wednesday, June 20, 2012

Multifamily Energy Savings: The Conflict of Interest

There are thousands of multifamily buildings in the Denver area that need some energy efficiency improvements.   The most cost effective of these improvements are usually simple control upgrades.

One example of the "lowest hanging fruit of energy efficiency":

Steam boiler systems cannot be zoned with individual 24V thermostats in each apartment.   Therefore, one thermostat controls the whole building, and the location of that thermostat is critical.  In a 20 unit building on 19th Avenue, I found it in the main hallway.   Unfortunately, the main doors were always cracked open a little, and so the hallway was always cold.   Over the years the heat emitters (radiators) had been removed from the hallways.

Therefore, that thermostat location caused the boiler to be on all the time, and all the tenants were roasting and opening their windows all winter to shed enough heat to be comfortable.   This is known as the "double hung thermostat method".

So, for $600, I purchased a steam-compatible thermostat and installed it in a more appropriate location.  The savings are more than $3000/year and will increase as the cost of gas increases.

The average energy auditor doesn't know this stuff.

It can only be learned through field experience as a heating technician, but books from can get you half the way there.   They can be read and understood by almost anyone.

A typical building owner might have a building that seems to have a higher utility bill than his other similar buildings, but since he doesn't know heating controls, he is forced to call a contractor.  Here's the inherent conflict of interest.  Even if the owner tells the contractor "please try to reduce the gas usage of this boiler" the contractor is loath to do anything that might cause a comfort problem and a callback.   The contractor  isn't responsible for the heat bill, but if he touches or upgrades the control system, he is suddenly responsible for having enough heat for every apartment.  So that contractor is more likely to make every apartment 74F instead of the 68F that the owner would prefer.

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