I am NOT a blogger and this is my first post (could be my last).
A very good friemd mine who lives in Chicago has an "urban Rehabber program" wher he teaches newbies and thse with little experience on how to become more profitable in the Rehab sector. As an Energy advocate archiect, I get his posts.
Here is one about MYTHS I thought some of you may be interested in (Just the messenger not the author)
More Energy Myths
Energy-saving tips that you can safely ignore
Posted on Nov 11 2011 by Martin Holladay, GBA Advisor
One more job you can cross off your list. Finally, some good news: It turns out that
you don't have to clean your refrigerator coils.
Energy myths are persistent, in spite of the fact that
energy experts spend a good deal of time performing debunking duty. Many energy
experts collect misguided energy-saving tips as a hobby, and pick the myths
apart with the dedication of an 18th-century amateur scientist.
In a previous blog, I presented my own list of ten energy myths. My collection included these old
Walls have to breathe.
Caulking the exterior of a house reduces air
R-value tests only measure conductive heat
flow.In-floor radiant heating systems save energy.
Two other myth-collecting hobbyists are Rick Diamond and
Mithra Moezzi, researchers at Lawrence Berkeley National Laboratory. They
presented their list of energy myths in a paper, “Revealing Myths
about People, Energy and Buildings.” Here are some myths they
- Cleaning the refrigerator coils improves refrigerator efficiency. According to Diamond and Moezzi, “A review of measured tests with refrigerators showed that there was no or little evidence of improved efficiency from cleaning the coils (Litt, Megowan, and Meier 1993).”
- Installing foam gaskets in electrical outlets will significantly reduce air infiltration. Diamond and Moezzi write,“The probable origin for this myth — an unusual case where an origin can actually be identified — was a study in the late 1970s that showed that 20% of the air leakage in fifty homes was due to wall outlets (Caffey 1979). Later studies showed leakage values for outlets to be under 1%.”
When it comes to energy myth debunking, Michael Blasnik leads the pack
Here's a selection from Blasnik’s myth list:
- Annual furnace tune-ups save energy. To debunk this myth, Blasnik quotes several studies, including one from Oak Ridge National Laboratory: “The approach of tuning up all units as a standard practice … is costly, probably unnecessary, and likely does not produce energy savings in many units.” Blasnik concludes, “Heating systems with savings potential are apparently too rare to make this approach worthwhile as general advice.”
- Annual air-conditioner tune-ups save energy. The problem with “generic” tune-ups, Blasnik notes, is that “most HVAC technicians don’t know how to measure air flow or refrigerant charge.” That’s why “researchers have found more problems in regularly serviced units.” Blasnik admits that a “high-quality” tune-up could save you energy; the problem is that high-quality technicians are very rare. “Even quality tune-up programs face the challenge that only a certain fraction of units provide good savings opportunities, while most units are operating close enough to correctly,” says Blasnik.
- Caulking and weatherstripping can save significant amounts of energy. Blasnik says, “Repeat after me: attics, basements, garages, and details are the real air leakage problem areas. Routine weatherstripping and caulking are likely to save less than 3% of your energy bill. … The savings will be unnoticeable in most homes.”
- Window replacement is a cost-effective energy retrofit measure. Blasnik notes, “When it comes to energy used for heating, savings are often overestimated. Reduced solar gain offsets about half the savings. When it comes to energy used for cooling, solar gain can represent half the cooling load, and low-SHGC glass can reduce this substantially. But the measure is still not cost-effective.”
- Closing hot-air registers in unused rooms saves energy. To debunk this myth, Blasnik quotes a study performed by Iain Walker, a staff scientist at LBNL: “The results of this study showed that register closing led to increased energy use for a typical California house over a wide combination of climate, duct leakage, and number of closed registers. The reduction in building thermal loads due to conditioning only part of the house was offset by increased duct system losses, mostly due to increased duct leakage.”
- Right-sized furnaces save energy compared to oversized furnaces. Actually, modern high-efficiency furnaces have very low off-cycle losses, and therefore operate efficiently under part-load conditions. Blasnik says, “There is very little data to suggest significant energy savings from ‘right-sizing’ equipment. I'm certainly not in favor of large oversizing, due to issues with noise, duct sizing (undersized ducts are even more undersized when you install a larger capacity unit), equipment size/cost, etc. But I wouldn't worry about going up to the next size.”
- Using ceiling fans in winter saves energy. Blasnik notes simply, “There is no evidence of any benefit.”
Blasnik has several other examples of energy-saving recommendations that result in zero or trivial savings. These include:
- Always put a lid on your cooking pot.
- Change your furnace filter monthly.
- Keep the refrigerator full (or add water bottles to a half-full refrigerator)
- .Close your curtains on winter nights. (This advice only makes sense if your curtains include a mechanism to seal the perimeter of the curtains, including the top, to prevent convection currents).
These measures make sense.
At most of his presentations, Blasnik balances
myth-debunking with a list of energy retrofit measures that are actually
useful. He recommends:
- Insulate your walls and attics if they are uninsulated.
- Insulate your attic if it is poorly insulated — but only after completing air sealing work on the top side of your ceiling.
- Hire an experienced contractor to perform blower-door-directed air sealing work, ideally with the help of an infrared camera.
- Seal the seams of any ducts located outside the thermal envelope of your home.
- Swap your incandescent bulbs for CFLs “wherever feasible and accepted.”
- Install high-efficiency appliances and HVAC equipment.
Some energy-saving tips are simple actions that don’t require any retrofit work. According to Blasnik, the following actions are well worth considering:
- Lower your thermostat setting.
- Set back the thermostat when you’re not home.
- Unplug second refrigerators and freezers.Make sure your furnace blower isn’t on all the time. (It should be set to “auto,” not “on.”)