Is room taking too long to warm up?

[hazetimesfive]

This idea of what goes in must come out, I would say the heating and cooling of a property is not a straight line, likely to be a curve.

 

[Aquaheat]

No, not telling - but it should be fairly obvious; you can see who "liked" my bucket post, for example.

But your bucket analogy doesn't hold water (pun intended)

Aquaheat, tell me, in my bucket analogy who do you think would use the most water in the long term?
I know this isn't a perfect anlogy, but it's sufficient for me to work out whether the reader has a basic grasp of the laws of nature.

(BTW in response to one post, I'm not suggesting that water would ever be allowed to flow over the brim of the bucket. The water all comes out of a hole in the bottom.)

With that you assume a constant and both would use the same amount of water but, and I'm only doing this to highlight your analogy, if I only needed that bucket to be full for 8 hours a day so allowed it to be empty for the remaining 16 hours and constantly topped up for that 8 hours who would use more water compared to filling for 24 hours constantly?

I already answered that. If both buckets are identical and the hole is the same size then the loss will be the same. I got that you didn't mean it to overflow. If a 5 gallon bucket leaked 1 gallon an hour and i filled at a rate of 1 gallon an hour so the bucket remained full I would use 5 gallons in 5 hours.

If the same bucket was allowed to empty you would actually use more water as you would be losing some while filling so lets say it takes half hour to fill I would use 5.5 gallons but....

If my bucket was constantly filled for 24 hours I would use 24 gallons

If I had to fill my bucket at 06:30 till 08:30 I would use 5.5 gallons. If I then left it until 16:00 to refill and topped up when empty until 22:00 I would use 8 gallons

Total in a 24 hour period of 13.5 gallons.

Jon

 

[Aquaheat]

Double post sorry.

 

[Aquaheat]

I would also estimate that if you have an intelligent thermostat, it would be more efficient with constant heating.

But with an intelligent thermostat they are aware of your away periods and turn the heating off only coming on at a certain time (or geo location) before you return depending on the internal temperature, ambient outside temperature and required set point.

Yes you are right that heating should be set to constantly on if you have an additional timer in conjunction with it but ideally the timer will be removed so that the smart controls can take full control of the system.

Jon

By intelligent thermostat I merely meant one that will apply smoothing to control temperature overshoot and dip.

Why would you want to apply smoothing to temperature control when the heat isn't actually needed in the first place?

 

[hazetimesfive]

I think there might be something wrong with your sums.

the bucket will continue to empty outside of heating periods. at 6:30 the bucket is empty and you will need to fill it at 2 gallons per hour and your house will not even be at the required temperature by 8:30.

 

[JohnD]

Heat loss from a room is proportional to temperature gradient (the difference between the indoor and the outdoor temperatures) and time.

So keeping it hotter for longer will lose more heat.

The bucket analogy does not work if the water leaks from the bucket at a constant rate.

 

[endecotp]

BUT IT DOESN'T LEAK FROM THE BUCKET AT A CONSTANT RATE!!!!11!!!1

As the water level falls, the pressure difference between thr bottom of the bucket and the outside drops so the rate of escape falls. JUST LIKE HEAT THROUGH A WALL.

AAAARRRRGGGHHHHH1111111!1!!!!!!

>deep breath<

 

[hazetimesfive]

rate of escape increases. that's why your tiny mind cannot comprehend.

 

[Aquaheat]

I think there might be something wrong with your sums.

the bucket will continue to empty outside of heating periods. at 6:30 the bucket is empty and you will need to fill it at 2 gallons per hour and your house will not even be at the required temperature by 8:30.

Try again. Bucket will be empty at 06:30 it fills at a rate of 5 gallons in 30 minutes but loses a gallon a minute so the first half hour takes 1.5 gallons. I can then leave it to empty for the rest of the time till 08:30 as there is still enough water to cover that. It's empty again at 16:00 but I have to fill it twice in a 6 hour period.

As has been mentioned before the bucket analogy doesn't work for heating!!!!

With regards to pressure loss over 14" of bucket how much does that affect the flow rate considering the available head? It's barely negligible. Again your analogy just simply does not work and has no founding in the OPs question!

@endecotp what is your solution or ideas regarding the OPs original question?

@hazetimesfive what is your solution or ideas regarding the OPs original question?

seeing as most of you guys can't even read the graph that he provided your advice and analogies have to be questioned.

If you truly believe that leaving heating on 24/7 is more energy inefficient then i lay down a challenge.

At 22:00 tonight post a photo of your gas meter reading. Leave it on for 24 hours constant with your stat set to 21C and repost another picture at 22:00 tomorrow.

Then time it for 2 hours in the morning and 6 at night to finish at 22:00 and take another picture.

Anyone willing to accept this challenge?

Jon

 

[hazetimesfive]

I have night storage heaters, how can i help

 

[bhm1712]

I think there might be something wrong with your sums.

the bucket will continue to empty outside of heating periods. at 6:30 the bucket is empty and you will need to fill it at 2 gallons per hour and your house will not even be at the required temperature by 8:30.

Try again. Bucket will be empty at 06:30 it fills at a rate of 5 gallons in 30 minutes but loses a gallon a minute so the first half hour takes 1.5 gallons. I can then leave it to empty for the rest of the time till 08:30 as there is still enough water to cover that. It's empty again at 16:00 but I have to fill it twice in a 6 hour period.

As has been mentioned before the bucket analogy doesn't work for heating!!!!

With regards to pressure loss over 14" of bucket how much does that affect the flow rate considering the available head? It's barely negligible. Again your analogy just simply does not work and has no founding in the OPs question!

@endecotp what is your solution or ideas regarding the OPs original question?

@hazetimesfive what is your solution or ideas regarding the OPs original question?

seeing as most of you guys can't even read the graph that he provided your advice and analogies have to be questioned.

If you truly believe that leaving heating on 24/7 is more energy inefficient then i lay down a challenge.

At 22:00 tonight post a photo of your gas meter reading. Leave it on for 24 hours constant with your stat set to 21C and repost another picture at 22:00 tomorrow.

Then time it for 2 hours in the morning and 6 at night to finish at 22:00 and take another picture.

Anyone willing to accept this challenge?

Jon

Yes Me!!

Count me in

 

[willingz]

I'd assumed that after initially heating my house what I have to pay for is the net loss of heat from the house. When its cold outside, the higher the house temperature the greater the heat loss so maintaining a high temperature overnight will cost me. But I have no relevant expertise, so perhaps I'm wronq.

 

[endecotp]

With regards to pressure loss over 14" of bucket how much does that affect the flow rate considering the available head? It's barely negligible.

Doubling the depth of water in the bucket will, to a first approximation, double the rate at which it flows out through the hole in the bottom.

Again your analogy just simply does not work and has no founding in the OPs question!

I'm honestly really surprised that even fewer people seem able to understand the basic physics of water pressure than understand the basic physics of heat flow. I really thought that the water analogy would help people to visualise what happens to the heat, but it seems to have just added more confusion. Sorry about that.

Regarding the original question - it seems that perhaps the radiator is undersized, but I have no quantitative contribution to that discussion. I posted initially in response to the CRAZY suggestion that energy could be saved by keeping the heating on continuously. Those of you who seriously believe that need re-educating.

 

[garmcqui]

Jesus, what have I started?!?

 

[endecotp]

Jesus, what have I started?!?

https://xkcd.com/386/