Which is more expensive to run, a window unit or central AC - assuming the wu runs 24/7 and AC is set at 74?
My apartment AC unit is being replaced, and in the meantime we have a window unit which freezes the bedroom and makes the rest of the apartment about 78-80 when we are home. The office manager argued that it is less expensive to run the window unit at 64 all day long than it is to run the AC . I disagreed with her. Our apartment is 1150 square foot, and while the window unit cools the bedroom the rest of the apartment is around 80 when we are home.
Central AC unit not cooling apartment?
Call your maintenance dept back in the morning and tell them you have consulted with several HVAC professionals. Make a formal written request via certified mail (keep a copy) to have the evaporator coil cleaned very thoroughly. This can most times be accomplished with a spray-on no rinse cleaner designed just for the evaporator, but sometimes it can only be done by temporary removal and cleaning with a considerably stronger cleaner, out in the yard. A good strong spray with the hose in the condenser coil wouldn't hurt either... The inside fan squirrel cage fan blades can also get caked with micro-dust and stop moving air efficiently. Have that cleaned too..Its all about the air flow, not just the refrigerant. Yes, the correct charge is terribly important, but its just one aspect of performance. Get up in the scuttle hole in your closet and take a fan to place at the gable of the building....if you can at all get a fan ventilating the attic space that will help your unit. If you have not already done so, change the return air filter. Now,... if you snag a small window unit, the power it will use is much less than what your electric bill has risen.... and it will take some stress off your central system. On the maintenance dept: advise the management in your letter that as the air conditioner is a supplied appliance, you expect the air conditioning to operate to your satisfaction. Bottom line. If they cannot or will not make that happen, you will exercise your right to call out qualified personnel to fix the problem, and deduct any and all costs from the rent. (in Texas, that's legal) It will cost you out of pocket, but it will be fixed and its essentially paid by the apts. -after all, its their responsibility. Here in Texas we have brutal summers. I did my own a/c work at my apt, and I keep my thermostat at 65F, 24/7.-my unit cycles as designed.
Why is it that if the thermostat at my house is set to 72 degrees in the summer, it feels warm, but the same 72 degrees in winter feels cold?
Humidity. It is the key to comfort. In fact it is more important than temperature. The higher the humidity, the less comfortable you are. The percentage of increase in humidity has far more impact than a corresponding increase in temperature. The reason is, we don't evaporate our sweat when it is humid. So our bodies don't cool down like they should. So we do what we can to remove as much as we can so we can be comfortable. In the winter we have to add it because it is too dry.When the air conditioning is running the humidity is low, but when it turns off the humidity begins to rise almost immediately. It rises at a higher rate than the temperature does. The net result is, the temperature is still at the shutoff point and we feel uncomfortable due to the rise of humidity. This is why oversizing a system is a bad idea. It will satisfy the temperature too quickly and it shits off. During the off period while it waits for the temperature to rise 2° the humidity is already uncomfortably high. A correctly sized system will run longer and keep the humidity controlled with minimal off time. The reason is it only removes moisture while it is running. So the longer it runs the more humidity control you have
How much does one light bulb cost per hour?
An incandescent light bulb costs about 50 cents and lasts about 750 hours. If you were to leave a 100-watt bulb burning for 24 hours each day, 365 days per year, it would use 876 kilowatt hours per year. (1000 watts equals one kilowatt – “kilo” means a thousand.) A kilowatt-hour of electricity costs about 15 centsBut if you use Led light bulbs, it will cost very low. Let me explainIf you run a single incandescent bulb 5 hours a day for two years, it will cost you around $32 (depending on your energy rates). Most of that money is spent on electricity. If you run a single LED bulb 5 hours a day for two years, it will cost you $12. But – $9 of that is just for the bulb!Find out best Led light bulb for you, EnVision LED light bulbsEnVision LED light bulbs provide the market with a clean and bright light that turns on to full brightness immediately. EnVision bulbs are 100% mercury free, don't have harmful substances or gases, and don't get hot for easy handling. Save up to 80% on electrical cost and bulb replacements by using EnVision's high performing and long lasting LED light bulbs.
Do you have some good tips to lower your electric bill?
I can answer this since I work for an electric utility. :) The best ways are to unplug appliances and things you don't use often as things that are plugged in still draw in energy even if they are turned off. Switch to CFL lightbulbs. Set your thermostat to 78 in the summer and 68 in the winter when you are home. And raise it 3-4 degrees during the summer if you are gone during the day. And lower it 3 -4 degrees during the winter if you are gone during the day. Or you can buy a programmable thermostat that will adjust at different times of the day so you don't have to mess with it. Turn your water heater temp down to 120 degrees Fahrenheit. Or you can even buy a timer for it and have it cut off during the day when you aren't home or in the middle of the night when you are asleep. You can also buy a blanket for it to help keep the heat in. Also if you live in an older home the windows aren't as efficient and tend to leak a lot of air through. So outdoor air will go in and indoor air will go out. Only use the cold water setting on your washer. It keeps from the water heater having to turn on to warm up more water. And always wash full loads. Try not to run your dryer for longer than necessary also. Digital picture frames use as much energy as your washing machine or fridge. We live in a 2500 sq ft home and our electric bill averages about $200 a month. My MIL lives in a 1500 sq ft house and hers is close to $500 a month. She keeps her A/C at 70 during the summer and winter, they have their water heater turned up to who knows what. I get scalded hands everytime I use her kitchen sink. And they leave lights on ALL the time.
Do you run your air conditioning all night and day?
My air conditioner thermostat is set to 72 F year round, except for possibly one or two weeks around January if we get lucky and have a Arctic cold front. Then I will turn it off and run the gas fireplace instead. We can’t really leave the AC off and our windows open for fresh air for several reasons:The pollen would blow in, causing everyone to be sick with allergies. This is especially true in the winter months during Cedar season when the pollen causes flu-like symptoms known as Cedar Fever. It’s brutal here in Central Texas. We have to filter our air through high quality filters to keep the dust, pollen, and pet dander to a minimum.Critters would enter the screened windows, like mosquitoes (West Nile Virus!), tarantulas, roaches, and scorpions.It never gets cool enough for long enough to justify turning off the air conditioner. We may have one or two days when the temperature outside drops to below 50F, but then two days later it’s back up to 85F. I was told by the maintenance crew that switching the AC off and on multiple times per day/week is hard on the electrical components.As a middle-aged woman (I HATE admitting that) who is going through peri-menopause I am starting to have hot flashes. Even with the thermostat set at 72F I get uncomfortably, scorching hot multiple times an hour, day and night. In addition to keeping the rest of the house at one temperature, the master bedroom is kept cooler and I have 3 fans blowing on me when I sleep: the ceiling fan, a floor fan near the foot of the bed, and a smaller fan on my nightstand. I also have ice packs in the freezer that I use on my chest and back to keep me cool. It really sucks.
Which will result in higher energy savings for an average home - replacing a very old AC unit or replacing very old (aluminum) windows?
To give an accurate answer, a load calculation should be performed on the heated structure, to measure heat loss/heat gain. Unless your windows are stuck open, your best bet is to replace your HVAC system first, to include close scrutiny of the ductwork. Once a correctly sized system with correctly designed ductwork has been installed, you must insulate. Beginning with the attic, crawl space, and exterior walls, old windows should be replaced with modern insulated windows. Thermostats should be set at 76°-78° COOL & 68°- 70° HEAT. Especially with heat pumps (in my experience), maintaining these settings 24/7 will deliver the most economical results as well as the greatest comfort. I don't recommend programmable thermostats unless the home is frequently unoccupied. Getting back to HVAC systems, there are many options. Inverter systems offer greater savings than standard 14 SEER equipment, albeit at considerably greater expense. You must do basic math to determine if the return exceeds the initial expense. Even so,, a simpler system will offer fewer potential service related issues and is actually cheaper in the long run in many cases. Case in point, I have serviced 40 year old furnaces with solid and intact heat exchangers that have had few repairs over its service life. Many times, the only repairs needed involved a fan belt and/or a thermocouple. The key is regular service and maintenance, and keeping the mechanical equipment area clean and dry. After 10 years, however, the homeowner should be prepared for major expense or replacement of the heating and air conditioning system. Newer systems are far more economical and efficient than the older furnace mentioned earlier.In conclusion, you must consult a reliable HVAC contractor. Don't trust a moonlighter with your safety and comfort. When comparing bids, keep in mind that the lowest bid is not necessarily your best option. In fact, it may be the worst possible decision ever.
Does closing vents in an apartment save energy?
closing the vents to rooms you don't frequently use is counter-productive. You're just going to create another "heat zone" in your house. It's going to build up unconditioned air that moves out a lot more slowly. What's the benefit in that? Besides, unless those rooms are totally sealed-off, the heat is going to come out of there eventually and drive up the temperature in other areas of the house. The first thing I'd do is try to block the light from coming in (solar gain). I bet you don't have low-emissivity windows so you could notice a big difference by purchasing some energy efficient shades for the windows of the sunniest areas. Depending on your air conditioner, it may or may not be cheaper to shut it off while you're gone. It probably also depends on how hot it's getting during the day when you're gone. You might try experimenting with keeping the ac on while you're away but at a higher temp (say 82) vs shutting it off then comparing the usage on your energy bill. You might also be able to make a small difference by caulking around your windows (air leakage). It can slow down the rate of loss to the outside for the air you're paying to cool.