[mzaslavsky]

We've recently moved to our new townhouse in MA, and it is a second month in a row we're shocked by our electricity bills. We have electric heat pump, it almost never operatres in aux mode (with electric strips), but our bills are close to $700/month (4500kWh). Essentially, to maintain 68F inside temperature, our heat pump has to work almost non-stop, though outside temperature is 32F(night)-40F(day). When heater is off, the temperature drops pretty quickly.

We're suspecting that there is something wrong with insulation. Townhouse was built in 1977, it is end unit (three exterior walls), nobody above and below us (we have two floors+walk-out finished basement=attic). We have double-pane aluminium sliding windows, as well as aluminium sliding doors to the patio and to the deck. During colder days windows, especially frames, are rather cold, and we easily (by our hands) feel cold air flow somewhere between frames and sash and somewhere between frames and walls. Before doing anything, I'm wondering what would be more cost-efficient, at least on a medium-term (5-7 years). Does it worth trying caulking/weatherstripping? Or, perhaps, it may solve all the problems? Or I have to invest in reinstalling the frames? Or replace windows entirely, to, say, thermally-broken aluminium ones? Or any other ones (say, combined)? I have a condominium restriction here that new windows have to look like current (aluminium) ones.

Also, walls can be rather cold sometimes. Can it be because of poor windows insulation or I have to consider walls insulation as well? Construction is frame, with brick exterior.

Any suggestion is highly appreciated! We really can't afford $700 monthly electric bills during winter (and possibly during summer).
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[joecaption]

http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table

Cheap contractor grade aluminum windows and doors may not have a thermal break built into the frames so all the cold or heat just transfers into the home.

Sliders are always a great big air leak waiting to happen.

Consider buy some of those heat shrink plastic window covers, add foam seals to the outlets and switches.

Air seal the attic, which means using expanding foam to seal any place the wiring plumbing, or ceiling fixtures were ran.

 

[djlandkpl]

In addition to Joe's suggestions, I would start with your attic insulation. See how much is up there. Adding blown in insulation is relatively inexpensive.

 

[joecaption]

If you buy at least 10 bags Lowes or HD will let you use there blower for free.

 

[HomeSealed]

Thermally broken or not, aluminum windows just aren't a good choice in colder climates. Eventually you'll want to replace those with vinyl, wood, fiberglass, or composite.
If you are looking for "bang for the buck", my recommendation would be to get a home energy audit. You'll get a comprehensive list of where your problem areas are, as well as what type of return you can expect in improved efficiency... and don't confuse a certified energy audit with some of these jokers running around doing "energy analysis". A real audit will consist of a blower door test, thermal cam analysis, safety checks on combustion appliances, computer modeling to determine potential savings, and then a post test afterward to make sure that the work was done right. Many states and municipalities have incentives for both the audits and/or the weatherization work. Even if you don't have such a program, you'll pay a few hundred bucks for invaluable info on the performance of your home.

 

[Dave Sal]

When I bought my home many years ago I was kind of shocked at the high heating bills during the winter months. The following fall I decided to add additional insulation in the attic so I added R-19 fiberglass insulation rolled across the rafters. My gas bill dropped in half the next year. :thumbsup:

 

[HomeSealed]

Improving your attic insulation to the appropriate levels is easily one of, if not the best "bang for the buck" that you can get in terms of energy efficiency.
If you are going to do it though, do it right. Research the appropriate materials, make sure that your ventilation is adequate, AIR-SEAL, etc. Cutting energy usage in half is highly uncommon, but there is certainly significant gain to be had.

 

[Fix'n it]

Improving your attic insulation to the appropriate levels is easily one of, if not the best "bang for the buck" that you can get in terms of energy efficiency.


Cutting energy usage in half is highly uncommon, but there is certainly significant gain to be had.

i kind of disagree with that. depending on the situation, air sealing is the "bang for buck. then insulation.

idk what the PO's actually had for a gas bill. they told me "a very affordable $100 a month, all year, plan" , and i bet it was higher. just the work i have done so far, about 1/4 of the total plan, we are just over $100 a month in the dead of winter.

 

[Fix'n it]

oh. and it is a very comfortable 73 in here. AND i plan to cut that bill in half, at least, with the finish of the work.

 

[HomeSealed]

i kind of disagree with that. depending on the situation, air sealing is the "bang for buck. then insulation.

idk what the PO's actually had for a gas bill. they told me "a very affordable $100 a month, all year, plan" , and i bet it was higher. just the work i have done so far, about 1/4 of the total plan, we are just over $100 a month in the dead of winter.

My point was that it should be done in tandem, along with insuring proper ventilation as well... But yes, air sealing is a VERY important component.
The reason that I suggested an energy audit, is that it will take a reading on the "tightness" of the home before and after the installed measures. The reason this is important is that in some cases, when a home is very well sealed, mechanical ventilation in the form of a constant run exhaust fan (or worse) can be necessary to prevent excessive moisture in the home. Even worse, if the home has any naturally drafting appliances such as a furnace or water heater, there could be serious safety concerns due to back drafting.