Questions tagged [water-heating]

raising the temperature of water. For questions about space-heating use the [heating] tag.

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17 views

How much coil do I need to heat a given length of pipe (as a function of x,y,z)?

I'm imagining heating some water pipes using heating coils similar to these. Under various conditions, would I need to apply almost continuous lengths of heating coil to the entire length of pipe? Or ...
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0answers
23 views

How to keep my tankless water heater safe in a cold room?

I have a room in my apartment that can sometimes get around 40°F (4°C), and that's where my new tankless water heater is stored. Should I take any special precautions to keep my pipes from freezing or ...
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1answer
41 views

Most energy-efficient way to keep my pipes from freezing without tearing up walls/floor?

I live in a second-floor apartment in the US Midwest. For a few weeks per year, I have found that I need to turn on the baseboard heater in my kitchen in order to prevent the pipes in the kitchen and ...
2
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1answer
47 views

Should I turn off my Gas Water Heater if I will be gone for 3 days?

I have a gas water heater. If I go out of town for a week during warm months, I've been told that I will save energy if I turn the heater off before I leave. Would that still be true if I was going to ...
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4answers
127 views

What is the most sustainable choice for a domestic hot water system in temperate, coastal Australia?

We currently have an ailing 14 yr old solar hot water installation. A few plumbers have given us the same story: due to the age and general condition of the system, it makes more sense to replace it ...
2
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1answer
65 views

When/where is it feasible to use a solar cooker to boil water?

Can a parabolic reflector-type solar cooker of reliably boil water? If so, what major factors determine how much/how intense sunlight is required to do this how much water can be boiled how long the ...
2
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2answers
134 views

How much more efficient is boiling water with a lid?

I sometimes end up boiling water in a pot without putting a lid on top because I can't find the lid. How much energy is wasted when bringing water to a boil without in a pot without a lid? Or ...
2
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3answers
85 views

How can I conserve energy and water in my bathroom? [closed]

I am interested in energy conservation and would like some simple tips on ways I can reduce my water and energy use in the bathroom in particular, as I feel that this is the place that I use the most ...
3
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1answer
65 views

Does a solar thermal hot water system make sense for my home?

Currently my house has a natural gas-burning hot water heater, with a 40 gallon (150 liter) tank. Given the vintage, the efficiency of this heater is likely around 80%. A new, drop-in replacement ...
5
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3answers
100 views

on demand water heater - propane vs electric?

We need to replace our (tank) propane water heater. We'd like to switch to a tankless heater, but we're waffling between propane and electric. I saw this question, which was really helpful, but we've ...
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1answer
58 views

Heat escaping very old cob house

I have just moved into a semi-detached house (rented) made out of cob, heated with a wood burner which also heats up the water for radiators and washing. There is also a large boiler,electrically ...
4
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1answer
143 views

Running boiler intake along chimney for preheating

My house has a boiler in the attic that provides hot water for taps and for central heating. On the opposite side of the attic is a chimney pipe for the fireplace on the ground floor. I was thinking ...
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1answer
114 views

How does one calculate the wattage of a biomass fired water heater

My newly designed "biomass fired water heater" gives 50 liters of boiled water within 20 minutes by firing 2kg of firewood. Room temperature is 30 deg. centigrade. Please let me know how to calculate ...
2
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1answer
132 views

How much energy would it cost to stabilize 2 tons of water at 70 degrees?

I'm trying to figure out the efficiency of energy usage between heating up 2 tons of water from 5°C to 70°C everyday (during winter) within a certain given time (let's say one hour) and stabilizing 2 ...
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2answers
79 views

Feeding hotwater into modern appliances

Most appliances, such as washing machines and dishwashers typically take cold water and heat it internally. This is probably the most efficient way on a grid connected house with electric water ...
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2answers
193 views

Heating water with compost

We've been experimenting this year with hot composting, and are now looking at how we can go about using the heat generated in the pile to heat water, either to use directly or to pump around as ...
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3answers
8k views

Should I worry about the minimum mark on our kettle?

Our electric kettle for boiling water for tea or coffee has what looks like a minimum mark at 0.8 litres (though on closer inspection it says “mini” rather than “min”!). I try to save energy by ...
6
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3answers
317 views

Good alternatives to a fuel oil heating system in an apartment block

I live in a building of 8 apartments, in Belgium. We share a communal fuel oil boiler in the basement to provide hot water and heat. For the latter, each apartment has radiators through which a hot ...
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4answers
3k views

Which is more energy efficient? Heating ten 1L water separately or one 10L water directly

Just like the title said. In my house, we are very heavy tea drinkers. So my mother tends to boil a lot of water every day. She usually does this with a small amount of water (1-2L) every time she ...
6
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1answer
103 views

Are there different types of water-source heat pump?

I have heard multiple names for water-source heat pumps. What's the difference between something called a water-to-water heat pump, and a seawater heat pump? Are they just different names for the same ...
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3answers
2k views

How to cover an open-top shower, to make it feel warmer while showering

There is a product on the local market in New Zealand called "Showerdome" that is a clear plastic dome that can be attached over the top of most open top showers. Covering the top of a shower reduces ...
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4answers
462 views

Pool, sauna and shower with electric heating and solar thermal vs gas heating?

I have four things that need to be heated on my house: Pool (28.000 liters solar thermal heated) Jacuzzi (I think that is like 400-600 liters is gas heated) Showers (actually they are all electric) ...
6
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2answers
5k views

How much power does an Electric Airpot use while on standby?

We have just brought a Buffalo K711 4.25L Electric Airpot that is great for my wife as she is disabled and can find a kettle hard to pour. I was expecting it to be well insulated, however its sides ...
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3answers
60k views

How many kilowatt hours of electricity does it take to heat 180 litres of water from 15 to 60 degrees C?

I think this calculation uses the specific heat capacity for water, which is from memory a bit over 4. Can someone please do the math? Also, if we assume electricity costs $0.30 per kilowatt hour, ...
12
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4answers
329 views

Water heating / electricity production by using earth's warmth?

I'm very curious, why hasn't anyone done this? In most places on earth, the temperature gets 25 degrees higher (celsius) for every kilometer in depth. How hard would it be to drill 4-5km, put a U-...
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4answers
2k views

How to measure the energy output of a thermal solar hot water system?

I have a (thermal) solar hot water system with electric heating, and I'd like to be able to measure the amount of energy provided by just the solar heating. The system is set up like this: Water ...
5
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2answers
49 views

I'm on mains gas and live in England, am I eligible for the domestic RHI?

The domestic Renewable Heat Incentive is about to launch, in different formats, to different constituent countries of the UK. It is an incentive to install particular accredited renewable heat ...
16
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3answers
2k views

Shall I boil water with a water boiler (cooker) or with a pot?

I know that when making tea it uses less energy when heating the water when using a water boiler(cooker), than when using an electrical plate. A water boiler is directly heating the water, while a ...
12
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4answers
2k views

Forcing water circulation in solar hot water installation

I'm planning an installation for heating water using solar "exchanger" panels (solar used to heat water directly, not through electricity). I don't want to bind the reservoir, panel and tap locations ...
15
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4answers
230 views

How can I decarbonise my domestic heating, given severe physical constraints?

tl;dr : For the millions of dwellings that have significant physical constraints imposed by the physical fabric of the building, its configuration and location, that rule out heat pumps, biomass and ...