Showing posts with label multifamily buildings. Show all posts
Showing posts with label multifamily buildings. Show all posts

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 HeatingHelp.com 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.

Thursday, May 17, 2012

Reports From the Field - Part I - Zone Valves in Apartment Buildings

EASY SOLUTION FOR ENERGY HOG APARTMENTS


Recently I have been performing energy audits of mid-size multifamily buildings, focusing on control problems, the true "low hanging fruit" of energy efficiency for these apartment buildings.


The most common problem we are seeing is zone valves that fail "open".   Tenants will not report this or complain about too much heat until summer.   In summer, no one is looking for boiler problems, and oftentimes the boiler is off for the summer, problem solved unknowingly.


This is not a trivial problem.   Just one zone valve that is fully open all the time in a building with constant circulation will waste at least $30/month.   We've seen 20 unit buildings using $100-$300 /month too much gas when this condition is present.


Landlords are cheap, but here's a situation where you have to spend a  little to save a lot.  The payback period will usually be under two years.   And don't forget:   Every $1000/yr saved in expenses makes your building worth $14,000 more in today's market.


Your average contractor isn't on the lookout for leaky zone valves.   He just wants heat in the apartments and no complaints.   And I can't tell you the reason, but Xcel Energy's energy auditors aren't trained to find problems like this.   


So that means you have to call me.  (720 435-5909)   Another guy in Denver who is great at this type of detective work is Mark Eatherton at 720 375-3107.


Here are my general recommendations:   

  1. If you think that your zone valves are more than 20 years old, replace them ALL.   Seriously.
  2. If they are more than 12 years old have someone check them out to see if any are leaking through.
  3. If you have the 3-wire style zone valves "White-Rogers" more than 12 years old, replace them ALL with Honeywell or Erie valves.   It's not that they are  unreliable, they are just harder to work with.   The average maintenance technician has no idea how they work, so he can't troubleshoot them, and thus you will have to call a more experienced (read expensive) heating tech.
  4. If you suspect your building is using too much gas or electricity, request a usage report from Xcel.  Contact the Building Solutions Center at  BSC@xcelenergy.com  or call  1-800-481-4700  .   Then email it to me at kevdickson@gmail.com and I will compare it to similar buildings and let you know if I think you have any problems.
  5. Don't stop there.   Have your consultant look for other energy wasting issues - more on them later.