EcoRenovator  

Go Back   EcoRenovator > Improvements > Appliances & Gadgets
Advanced Search
 


Blog 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 12-11-23, 02:11 PM   #1
Barrowman
Lurking Renovator
 
Join Date: Oct 2020
Location: North Lincolnshire, England
Posts: 29
Thanks: 3
Thanked 1 Time in 1 Post
Question Improving central heating

Like many people we have gas central heating. What I often wonder about is trying to make it work better. What I am thinking about is how the heat fills the room. So the heating comes on, the temperature in the radiator rises and cold air at the bottom rises through it and continues on rising towards the ceiling. This continues until the air at the level of the thermostat has reached it's setpoint and it turns the heating off. This means the air above it is hotter than the setpoint and that below it is colder.

I did think that a ceiling fan might help but the air it pushes down wont go far unless the fan is quite powerful. So what I'm wondering is would it work better if there is a fan below the bottom of the radiator blowing the cold floor level air up through it. This would warm a greater amount of air per minute but it would be cooler and the fan would be constantly dragging the colder air down thus evening out the temperature from ceiling to floor.
Does that sound practical or can you see some error in my reasoning?

Barrowman is offline   Reply With Quote
Old 12-12-23, 02:15 AM   #2
Piwoslaw
Super Moderator
 
Piwoslaw's Avatar
 
Join Date: May 2009
Location: Warsaw, Poland
Posts: 961
Thanks: 188
Thanked 110 Times in 86 Posts
Default

I once started a discussion about increasing the efficiency of my heating system by lowering its temperature:
How to lower heating system temperature?

There Ryland proposed installing fans under the radiators, mostly to increase the heat transfer (more heat to the room, with the extra benefit of lowering the temperature of the water returning to the boiler for additional efficiency). These would also slightly boost air circulation, as you mentioned.

Since then I have had 120mm computer fans under most of the radiators in the house. Do they help? Yes, but not enough to measure. Mostly because the effect of the low flow from the fans on the massive, cast iron radiators is a tiny percent of all of the energy.
The effect on lighter, thin radiators would be much more noticeable, especially with higher effeciency fans, blowing air across the full length of the radiator, not just a 120mm segment of it.
__________________
Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.
Piwoslaw is offline   Reply With Quote
The Following User Says Thank You to Piwoslaw For This Useful Post:
Barrowman (12-12-23)
Old 12-12-23, 03:23 AM   #3
Barrowman
Lurking Renovator
 
Join Date: Oct 2020
Location: North Lincolnshire, England
Posts: 29
Thanks: 3
Thanked 1 Time in 1 Post
Default

Thanks Piwoslaw. it's as I thought. We do have the thin radiators. Because the air nearer the ceiling will be the hottest in the room then that's where the greatest Δt will be causing more heat loss than with what I hoped would improve the overall efficiency.
I did think it would be better to have the airflow increased across the whole of the radiator.
I have been wondering how I could do it without using a lot of power to produce it. I guess there has to be a sweet spot but exactly what that would be is probably something I would have to do empirically. I might get a few smaller PC fans and arrange them in a row along the bottom rather than a bigger fan with ducting. I can get 4 of the 60mm fans from Amazon at GBP9 and they are 5V 0.1amp each with air flow of 13.8CFM
Barrowman is offline   Reply With Quote
Old 12-12-23, 07:37 AM   #4
Piwoslaw
Super Moderator
 
Piwoslaw's Avatar
 
Join Date: May 2009
Location: Warsaw, Poland
Posts: 961
Thanks: 188
Thanked 110 Times in 86 Posts
Default

Quote:
Originally Posted by Barrowman View Post
I have been wondering how I could do it without using a lot of power to produce it. I guess there has to be a sweet spot but exactly what that would be is probably something I would have to do empirically. I might get a few smaller PC fans and arrange them in a row along the bottom rather than a bigger fan with ducting. I can get 4 of the 60mm fans from Amazon at GBP9 and they are 5V 0.1amp each with air flow of 13.8CFM
If I were to invest more into this idea, I would experiment with a squirrel cage fan, but with a looong fan, like this:

This would give an even flow over a longer length.

If you do go with the PC fans, take the largest diameter you can. Take the next largest and mount it diagonally to make it fit. The reason is noise - the smaller the fan, the higher the rpms and the worse the noise.
I had to put a resistor on 1 or 2 of mine to make them acceptable by the family.
Attached Thumbnails
Click image for larger version

Name:	fan.jpg
Views:	654
Size:	6.7 KB
ID:	9498  
__________________
Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.
Piwoslaw is offline   Reply With Quote
Old 12-12-23, 08:45 AM   #5
Barrowman
Lurking Renovator
 
Join Date: Oct 2020
Location: North Lincolnshire, England
Posts: 29
Thanks: 3
Thanked 1 Time in 1 Post
Default

The ones I mentioned say Noise:26dBA. And some 30mm ones say 15.92dBA which I can get 6 for GBP10. No idea what airflow they produce as it's not stated. Bigger fans would need to be tilted quite a lot as the radiators are quite narrow. The double ones are only 72mm wide so if I got bigger fans I would need to add some sort of ducting to route the air. The squirrel cage one looked like a possibility but I've not found anything suitable here so far. They all seem to be large diameter and short and are 240 volts except for 1 which was a replacement for a fireplace and had a built in heater so was not cased as it was for fitting internally.
Barrowman is offline   Reply With Quote
Old 03-16-24, 04:24 PM   #6
dguzzi
Helper EcoRenovator
 
Join Date: Nov 2014
Location: Michigan
Posts: 68
Thanks: 3
Thanked 2 Times in 2 Posts
Default

Along these lines I thought of a central duct with a fan pushing cooler basement air up and another fan pushing warm attic air down. (adding to heat or cool the main floor)
Then I though about a reversable fan/blower instead, but all the sensors to make it automated made me crazy....
I still think its an idea worth trying but I don't have the means to implement it (so far)

dguzzi is offline   Reply With Quote
Reply


Tags
economy, fan, heating, temperature

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:31 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design