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Questions tagged [energy-efficiency]

Questions about ways to measure and improve the ability to get useful work out of devices that consume energy. This includes coal, oil and gas as well as electricity.

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Can HRV be filtered on the outgoing side? Ducted?

JThis may be two questions, but they're both about HRV airflow so let's try it this way... I'm interested in eventually adding a Heat Recovery Ventilator (HRV) to my basement workshop, for fume ...
keshlam's user avatar
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0 votes
0 answers
13 views

How to insulate and air seal partially finished wall

I'm trying to slowly improve the energy efficiency of my house. I need to finish a 2x6 framed wall between my basement mechanical room and a poorly insulated, unheated garage (There is living space ...
kimjay's user avatar
  • 1
1 vote
1 answer
38 views

Ok to Have Soffit Vents Next to HVAC Registers?

I have a one-story wood frame home with a fully insulated attic, with 4 large vents at the ridge line and numerous perimeter soffit vents, each consisting of 4 large screened holes drilled in the ...
Rob C.'s user avatar
  • 11
1 vote
0 answers
67 views

Sealing baseboards in an old home

I own a beautiful old Victorian home from 1905. A few months ago, we got a home energy audit. Unsurprisingly, the audit revealed that our walls leak like a sieve. The auditor said we had literally the ...
Paul Tveite's user avatar
1 vote
1 answer
159 views

Can I plumb a heat pump hot water heater in-line before a tankless hot water heater?

I remodeled a house a few years ago with a propane-fired Vitodens 100-b1KA Combination boiler/tankless hot water, but I got tired of the inconsistent hot water temperature and the exhaust venting into ...
Carson Michaels's user avatar
1 vote
1 answer
55 views

Energy efficiency and window frames [closed]

I am trying to better insulate a few rooms in our home that run colder than others. We have floor to ceiling windows at one end our house, which I understand will generally make the area colder, but I ...
Zach Overgaard's user avatar
0 votes
0 answers
67 views

How do I tackle insulating rim joists with brick in a partially finished basement

I have done a fair bit of research on this, but still left with a dilemma. Here's some basics: 1920s single level, brick built home (see photos linked below). Exterior brick is painted. located in ...
Mike's user avatar
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0 votes
0 answers
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Energy efficient home improvement tax credit

I have been doing some reading for the tax credits available for furnace and heat pump installations. https://www.irs.gov/credits-deductions/home-energy-tax-credits and https://www.energystar.gov/...
Ayusman's user avatar
  • 131
1 vote
1 answer
142 views

How can I heat up my apartment more efficiently?

I live in a studio apartment that I rent from my parents, in France. Each winter, it gets very cold. The region is very sunny, but the specific area around my building is significantly colder (due to ...
C. Crt's user avatar
  • 163
2 votes
1 answer
224 views

HPWH better to raise temperature or use high demand mode

I have a hybrid heat pump water heater (compressor plus resistance heating elements). I'm going to have company over for a week so 6 people, instead of 2. Is it better to increase the tank temperature ...
Josh Wyss's user avatar
1 vote
2 answers
63 views

How best to air seal kitchen pantry ceiling

We just moved in and had an energy audit done by a professional, and they flagged that we were losing a ton of air through the ceiling in our kitchen pantry/ closet. The ceiling itself is a weird ...
noc's user avatar
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1 vote
1 answer
185 views

Insulating back of wall from attic space

I have a 3rd floor area with a crawl space all around it with some failing 2x4 bats of insulation, the critters and age have it rolling off the back side of the walls. I was just going to place the ...
Markpelly's user avatar
1 vote
1 answer
66 views

Heat Pump Air Exchanger efficiency gains in Snow/Cold

I have a 5 ton Bosch air to air heat pump, just installed last fall. I built a small timber framed cover to protect it from snow. One thing I was hoping to also do was to cover the sides of the small ...
Markpelly's user avatar
0 votes
0 answers
46 views

How to Airseal and Insulate Texas Homes

I am interested in what I can do to help improve the energy efficiency of older Texas homes. I am looking to purchase one in the new year but it is my understanding that in 2012 the energy efficiency ...
Lance's user avatar
  • 1
4 votes
2 answers
875 views

What is the difference in efficiency between upflow and downflow furnaces?

I have been doing a bit of research on HVAC systems, and recently learned about upflow vs downflow configurations, and understand that upflow is supposed to be more efficient for heating and downflow ...
Herohtar's user avatar
  • 192
1 vote
1 answer
463 views

Does an air conditioner's fan use more power on Max than on Auto?

I have an inverter air conditioner unit. I usually set it on 26°C, to save energy consumption. I live in a really hot area (it's 34°C right now (~93°F), in the middle of the night). My questions is ...
Marcelo's user avatar
  • 11
0 votes
0 answers
18 views

Fixed vertical space over concrete suspended floor - how to allocate between insulation depth vs. screed depth?

I have an extension being built on usual concrete beam & dense block over a ventilated void. The external extension area is 3 x 6m. Ventilation is via two 215x65 plastic airbricks and telescopic ...
Stilez's user avatar
  • 630
0 votes
1 answer
55 views

Separate furnace energy usage from other appliances?

I am looking to reduce my utility bills. It only makes sense if I know what my current energy usage (natural gas, electricity, etc) is for a given applicance (furnace, water heater, etc) before ...
Camron B's user avatar
  • 141
0 votes
4 answers
1k views

Leaving second floor window open while running central AC [closed]

We know that windows should be closed while running the AC, but since the central AC and thermostat of my house is on the first floor, I was wondering whether leaving the window open decreases the ...
user2233706's user avatar
9 votes
9 answers
4k views

Why would water faucets use a different energy source from the radiators?

In my apartment, hot water in the faucet is heated by an electric heater, while the hot water in the radiators for heating the rooms comes from a central gas boiler in the building. To me it seems ...
0x60's user avatar
  • 201
1 vote
3 answers
251 views

Is high standby power consumption of heat pump water heater normal and how to reduce?

I recently got my very well working tankless gas water heater replaced by a Rheem ProTerra 50gal HPWH. I feel the water heater consistently draws way too much power (I measure with CT clamps). ...
divB's user avatar
  • 1,365
0 votes
1 answer
102 views

Criteria for Energy Star energy estimates of heat pump water heater

Every heating appliance in the US features an "Energy Guide" label stating "typical" usage. In my case, the Heat Pump Water Heater states an estimated yearly energy use of 837kWh. ...
divB's user avatar
  • 1,365
1 vote
0 answers
423 views

How can I insulate the sloped ceiling of an attic room?

We have a century home. First two floors do well in summer / winter, 3rd floor is always too hot or too cold. The attic was completely uninsulated. The plan was to use batt insulation on the attic ...
user6912880's user avatar
1 vote
4 answers
456 views

How to make this pulley system more efficient?

I am trying to make a portable pulley system to lift heavy stuff. I made the following prototype using 8 individual pulleys: When I pull the rope, the load should seem approximately 8 times lighter ...
Martin Drozdik's user avatar
14 votes
4 answers
5k views

Plugging refrigerator only when necessary? (bottled beers)

I have a small and cheap refrigerator that I use to store beers. It has a small freezer that is of no use to me. I am only using this refrigerator 5 times a year (during "events"), and I ...
ChipsMyName's user avatar
1 vote
2 answers
84 views

Proportional circulation pump control - possible for "simple" pumps?

Thinking of implementing proportional pump control to raise efficiency in our hot water based heating system. Proper proportional control is possible using PWM control in high quality pumps like the ...
ppeterka's user avatar
  • 151
21 votes
10 answers
7k views

Why does bleeding radiators save energy?

I wanted to bleed my radiators by myself for the first time and I was wondering what is the reason that bleeding radiators saves energy? Most of the guides on bleeding radiators mention that this is ...
user161351's user avatar
1 vote
1 answer
371 views

Real world difference between a 0.18 W/m^2k U-value and 0.22 W/m^2k U-value

I'm currently choosing the thickness of the PIR insulation I will use for the ground floor (first floor US) in my house. It's a traditional (UK) suspended timber floor build with concrete foundations ...
abdnChap's user avatar
  • 214
24 votes
4 answers
7k views

Why would a particular heat pump model be illegal in my state?

I am trying to replace an electricity-hungry whole-house electric furnace with something that will be more cost-effective. I live in a high-altitude part of New Mexico, where I don't need to use much ...
Village's user avatar
  • 1,045
0 votes
2 answers
113 views

Is there more to consider than the R-value when installing stucco in the Southwest?

I live in the Southwest and notice 90% of the homes in my area are stucco. Since I'm considering wrapping the house in an additional layer of insulation, then new siding, I am considering stucco. Many ...
Village's user avatar
  • 1,045
3 votes
4 answers
2k views

Are new aircons with less BTUs more efficient than the older ones?

I am trying to replace the air conditioning device at home but I am not sure how to compare my old Panasonic that was bought in 1999 (possibly model of 1997 or 1998). Some facts: I was not able to ...
Datacrawler's user avatar
1 vote
1 answer
174 views

Should the door be open or closed between two separate HVAC systems?

We recently built out an additional 600sqft theater room in our attic. It’s a big room with 14’ high vaulted ceiling. We live in Houston and room heat load is fairly high. We installed a 2-ton unit ...
Bill's user avatar
  • 31
31 votes
11 answers
9k views

Why are so many radiators installed beneath a window (at least in Germany)?

I live in Germany and I always wondered why the radiators in most apartments are installed right beneath a window. The pictures below show an example (this is an older building, but you see similar ...
André's user avatar
  • 311
0 votes
1 answer
92 views

Home energy monitoring in split floor with one compressor

I have an odd situation where I live on a floor split in two and I want to split the electricity bill fairly with my floormate. I am looking at the home energy monitoring systems that have all the ...
tristatedud's user avatar
2 votes
1 answer
811 views

increasing R-value for old vaulted ceiling

I have vaulted ceilings in the main living space. Internally there are 2x6 joists between the roof and the drywall and the insulation I am guessing is original from the 1960's so this section of roof ...
dmoody256's user avatar
  • 191
3 votes
3 answers
1k views

Is it more efficient to heat a room using an air conditioner (heat pump) when the windows are open?

In general, using an air-conditioner for heating is more efficient than a standard electric heater or radiator. But in our home, we keep the windows open all the time, in order to decrease the chance ...
Erel Segal-Halevi's user avatar
20 votes
7 answers
7k views

Why is my house energy efficient only in winter?

My electric utility company sent me a graph of my home's electricity usage over time as shown in the picture below. My home beats what the company considers as efficient homes in the neighborhood when ...
Fijoy Vadakkumpadan's user avatar
0 votes
1 answer
97 views

Using water cooler for CNC laser as residential heat pump

I want to save money on heating bills. Residential heat pump systems cost thousands of dollars, which I can't afford. I am considering using a heat pump marketed to chill water for cooling CNC lasers (...
Diogenes Creosote's user avatar
2 votes
0 answers
69 views

Where can I find the efficiency of my heat pump with respect to temperature?

I can heat my house either with a standard gas heater, with a documented efficiency of 0.9, or with an heat pump, with a standardized coefficient of performance (Seasonal Coefficient of Performance) ...
Maxime's user avatar
  • 201
7 votes
2 answers
2k views

(When) Does room messiness affect water heater efficiency?

I have what I think of as a "standard US electric standby water heater." I will update this when I know the model; I am out of town right now. It is located in a cold, cluttered closet in a ...
capet's user avatar
  • 471
1 vote
2 answers
140 views

Most efficient heating system @ ~41° N

I'm researching building a home on a property I just bought. Water is plentiful but there is little or no chance of getting municipal services such as natural gas or electricity. However I have open ...
mreff555's user avatar
  • 1,287
6 votes
1 answer
511 views

How do the old and new (post-2021) EU energy labels for LED light bulbs compare?

One of my light bulbs recently failed, for the first time in a few years, and I had to go buy a replacement. Usually I try to look for the ones with the best EU energy label rating, since not only do ...
Ilmari Karonen's user avatar
2 votes
2 answers
341 views

If I live in the US Southwest, would a heat pump or conventional dryer use less energy?

Suppose I live in Poway, CA (weather), where temperatures are roughly between 50 and 90 F throughout the year and relative humidity is generally between 40 and 60%. With climate change the highs have ...
matmat's user avatar
  • 161
2 votes
0 answers
115 views

What is the optimal number of solar panels for my house?

Just had a solar power tech stop by. With the orientation of our house and the solar load, our property (house + workshop) can support roughly 41 panels. Each panel provides 370 W (max)...which ...
tnknepp's user avatar
  • 1,376
4 votes
8 answers
29k views

120v vs 240v Mini Split Efficiency

I am under the impression that, as a general rule, 110v heating and cooling options are inherently not very efficient. So I was surprised to find a 120v mini split shopping around with a fairly decent ...
grovberg's user avatar
  • 203
1 vote
3 answers
1k views

Is there a low-e alternative to double-pane gas-filled window panes?

I spoke with a local glass retailer and he said instead of using double-pane gas filled windows, I could instead use a 3-layer sandwich of, say, 1/8", 1/4", 1/8" panes to achieve the ...
nielsbot's user avatar
  • 131
25 votes
8 answers
7k views

How to find electric device(s) driving a high electric bill?

The cabin electric bill came and I gave it what I thought would be a cursory glance and it looked unusually high. Not just for this cabin, but in my experience with our houses. Our main house is a ...
user avatar
1 vote
3 answers
2k views

Why is Condenser energy guide rating different from advertised?

I'm installing a Carrier 24APB6 which has advertised up to 17 SEER. The seller tells me it is a 16 SEER unit but the yellow Energy Guide sticker on the condenser gives it a SEER rating of 14 on a 13-...
simgineer's user avatar
  • 127
36 votes
9 answers
12k views

Can I gain AC efficiency by spraying condensate water on the outdoor coils?

Recently, I was working from the basement and I noticed tonnes of condensate water going down the drain, and thought I might re-use it to improve the efficiency of my home AC system. So I put a ...
Billy left SE for Codidact's user avatar
-1 votes
1 answer
149 views

same-sized alternatives to F14T12 bulb

I have two bathroom light fixtures with very old magnetic ballasts and F14T12 fluorescent bulbs. These are, of course, a 1.5-inch diameter. I've been doing some bathroom renovations and I thought this ...
Eric Marsh's user avatar

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