Hot Water Rad - A Few ECU Fans and a Timer Switch

[JayPoorJay]

Good Afternoon, Good People.

I know this will be an elementary little project for most if not all of you, but I thought I would write a post and get put on track, rather than bumbling my way through it with all kinds of trials and errors.

I REALLY would appreciate y'alls help.

This is the problem - My wife and I purchased a big ol Victorian/Colonial House in NYC two years ago. The kitchen is surrounded on 3 sides by exterior walls, there is also a 1/4 of the kitchen floor (ceramic tiles) that has a crawl space underneath, and the kitchen gets FREEZING cold during the winter.

Until last week the hot water radiator in the room was WAY undersized. Thankfully I was able to replace that this past weekend with a much larger (and beautiful) antique rad we hunted for and found.

What I want to do, like to do, is use maybe 3 or 4 small ECU fans and hide them in and around the rad, in sensible location(s), that will force a little more air into, through and out of the radiator matrix into the surrounding space. Quiet low power fans, you know the type.

I think, finding the individual fans, mounting them up to the rad is no problem. What is, is rigging them up so they will go ON when the furnace or zone pumps go on (preferably the zone pumps) and having them stay on for as long as 10-20 min after the pumps and furnace shut off/down.

Are there any products/devices folks are aware of that will make this little project semi painless?

Again, I appreciate any and all help y'all are willing to offer. Even if you tell me its a bad idea.
Im all ears, and thanks in advance!

[stj]

maybe a thermal switch mounted to the radiator feed pipe to turn them on when there is heat would be better

[momaka]

IIRC, timer delay devices (both for ON or OFF delay) do exist. I actually have one... but it's somewhere in deeper storage, so may take a while before I can get a part number for you. All I remember about it is that it is a delay OFF timer (i.e. can disconnect a contact after a certain time has passed after power is removed) and has configurable time settings from a few seconds to a few hours.

That being said, you would need to know what type of signaling the furnace and zone pumps use (i.e. AC or DC and the amplitude of the voltage) in order to determine if there is even a time delay device that can be used with that (or alternatively, how to convert the signaling.)

As for the fans, you can probably use a few 12V PC fans and run them on 6-9V for more quiet operation... or a quiet multi-speed AC blower fan set to a low(er) speed.
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Now, I don't meant to discourage you from the project, but I've lived in an old wooden house before (early 50's 1-story duplex with crawl space) and I think you will find that simply placing a few fans on a radiator will not make the space that much warmer. In my case, the duplex place I rented had zero upgrades done to the structure since it was built in the 50's. Wall, roof, and crawl-space insulation were completely non-existent. And with that, I could barely keep the place 10 degrees Fahrenheit below or above the ambient temperatures outside. Specifically in the winter, I could sit and actually watch the temperature indicator arrow on the thermostat drop as soon as the forced hot air gas furnace turned off - this in a place where it didn't even get that damn cold in the winter (Norfolk, Virginia - i.e. mid-40's F was the norm... though always accompanied by "a bit" of wind, being near the ocean.) All I can tell you is I had the thermostat set to 65F, and most parts of the place would barely make it to 61F on average. The room where I slept being the largest room, could not be brought up above 55F if the temperatures outside dropped below 45F. Worst of all, the amount of gas I used to heat that place would rival (and sometimes be more expensive) than my parent's large(ish) 3-story house (a build from the early 90's, but with proper insulation... at least for US standards.)

So anyways, my point is that perhaps you might want to shift your focus on insulating the house better, if that's possible. Not an easy task, I know (especially if you elect to do this yourself.) But it will pay for itself a lot quicker than anything else. Getting the crawl space insulated will probably yield the most noticeable results, especially with a ceramic tile floor. In this case, the thermal mass of the ceramic tiles coupled with good insulation will actually make the temperature in the room a lot more stable and less likely to feel cold. And it may be something you can DIY a little more easily, at least compared to the walls - those will probably require a teardown either from outside or inside the house... which obviously is not an easy (or cheap) task.

maybe a thermal switch mounted to the radiator feed pipe to turn them on when there is heat would be better

Good idea, but only if the O/P has an easy way to measure the temperature of the radiator so that the "cold" and "hot" set points can be determined in order to choose a proper thermal switch... and that can get a bit tricky.

[redwire]

The boiler water temp may be simply too low, or not have an "outdoor reset" where boiler temps increase as outdoor temps go down. I would make sure the boiler controls are set properly and the outdoor temp sensor is OK.

I don't think the fan is the right solution - the rads are usually in a series string so a fan blowing on one rad will boost heat transfer but cool the water for everyone downstream.
I had cooler bedrooms and added a zone valve and homemade delay timer so the (hotter) kitchen zone valve opens after about a 1 minute delay compared to the bedrooms. This works great.
You can buy low cost pipe-clamp thermistors to know the rad temp, and then with air temp it is possible to know when a fan should run.
This assumes you have enough heat (hot water) supplied in the first place. I would look at how the house is set up, if it has any zone valves, outdoor reset, variable speed pump etc.

[JayPoorJay]

Hey ALL. Thank you for the ideas, thoughts and suggestions.... Much appreciated.

The house was recently treated with blown insulation in the walls. It holds heat amazingly. In the summer, one can expect it to be 10+ degrees cooler inside than out having held onto the cool over night air. And, in the winter, the entire place is cozy and warm and our bills believe it or not are not a killer. Natural Gas with a new modern boiler. All of the very large rads in the house are sized perfectly for the spaces they heat. We do pretty well there.

The kitchen on the other hand is an outlier for the reasons described. 3 walls exposed and a void under 1/4 of the floor (which would be tough to change. Windows are new.

I don't think I want to go in the direction of making the on off cycle dependant on what temperatures are being reported by water in the pipes. Sounds complicated .

What I was imagining was a dedicated power source that is "switched" when power is sent to the pumps. Let's say if the switch is a 120 volt switch (with timer built in) and it is triggered to turn on and off when the signal is sent to the pumps. And, when the pumps turn off, being powered by a secondary source and timed, the fan could continue to run for,,,, well, getting a sense of how long the furnace runs between starts and stops to maintain heat in the space, those settings would have to be fiddled with over time.

I have lived in a lot of places with rad heat and one of the tricks I have always used, and still use sometimes here, is just to direct a fan at the rad. My experience has been although the air will strip some heat away from the metal of a large surface area of the radiator , it will have little effect on the interior moving water temperature. Again, I'm talking small fans here with a low CFM rating. Thing about what's going on here as opposed to a living room or bedroom is we don't really want a fan running in the kitchen that way.

So yeah, I am just hoping to get some ideas that will help me get around devices, approaches and well, the many things I need to be thinking.

Ears still wide open.

Love the ideas of running the fans at a lower voltage to keep down noise. That will definitely be something I will want and need

Thanks again y'all

[JayPoorJay]

What's this thing?
DC 5V-36V Timer Module Cycle Delay Timer Switch Turn On/Off Relay Module with LED Display https://a.co/d/7Z6kylo

[JayPoorJay]

So... I ripped apart a bad floor heater type thing I found at work, and these are the power ratings for the fans. (see pic)

For anyone who is still with me, what I want to do is place these fans (two identical fans) under the 4.5 foot long radiator and have them come on when the boiler triggers the pumps in "zone one". Then, when the boiler and the pumps shut down, have them continue to run for 20-30 min (shorter or longer to be determined) on a timer of sorts. Are there any electronic device anyone can point me in the direction of to accomplish this? Could you walk me thru it a little?

[sam_sam_sam]

So... I ripped apart a bad floor heater type thing I found at work, and these are the power ratings for the fans. (see pic)

For anyone who is still with me, what I want to do is place these fans (two identical fans) under the 4.5 foot long radiator and have them come on when the boiler triggers the pumps in "zone one". Then, when the boiler and the pumps shut down, have them continue to run for 20-30 min (shorter or longer to be determined) on a timer of sorts. Are there any electronic device anyone can point me in the direction of to accomplish this? Could you walk me thru it a little?

A better approach would to use a thermal sensor controller ( something like this one or something similar )

https://www.ebay.com/itm/33510970238...Bk9SR669x-ngZA

set up to monitor the temperature of the water that is in your boiler and when it gets to a certain temperature turn off ( for example 80* F ) the fans and when the temperature in the kitchen is below the set point it turns on ( for example 68*F ) but only runs when you have the hot water available and not based on time but temperature only for better results

Here is an example of a situation with a pool and having the pool pump come on every day for a certain amount of time the already made units have a flaw in that if you have a power outage your timer will off and if you have this situation happen several times over a period of time then timer is useless and when you have daylight savings then even worse because in the winter months you do not need to run as many hours as it does in the summer months

I had a better approach and it was based on the sun was out playing I used a micro controller to accomplish this task I had it worked like this ( used a time ic chip for the keeping the time ) it would run for one hour and off for two hours and repeat this routine until the sun went to sleep at night this was the summer routine the winter mode was a little different in that it ran 30 minutes and off for 3 hours and it had a selector switch for weather it was summer or winter mode and made it very easy to switch mode just switch to the other mode and power up the micro controller and have changed modes

Yes I did have to write the routines and had to understand how to control the time ic chip and used an green LED light as the sensor to see if the sun was out playing and figure out how to have two different modes for the summer and winter but the most important consideration was that I did not want to have reset the timer for any reason for example power outage time change this was the motivation behind this project when I started the problem that I was having with the pool pump running I wanted a solution that I could setup and not worry about except for two times a year and all I needed to do was power down the micro controller and and flip the selector switch and power up the micro controller and was back up and running again

[JayPoorJay]

A better approach would to use a thermal sensor controller ( something like this one or something similar )

https://www.ebay.com/itm/33510970238...Bk9SR669x-ngZA

set up to monitor the temperature of the water that is in your boiler and when it gets to a certain temperature turn off ( for example 80* F ) the fans and when the temperature in the kitchen is below the set point it turns on ( for example 68*F ) but only runs when you have the hot water available and not based on time but temperature only for better results

Here is an example of a situation with a pool and having the pool pump come on every day for a certain amount of time the already made units have a flaw in that if you have a power outage your timer will off and if you have this situation happen several times over a period of time then timer is useless and when you have daylight savings then even worse because in the winter months you do not need to run as many hours as it does in the summer months

I had a better approach and it was based on the sun was out playing I used a micro controller to accomplish this task I had it worked like this ( used a time ic chip for the keeping the time ) it would run for one hour and off for two hours and repeat this routine until the sun went to sleep at night this was the summer routine the winter mode was a little different in that it ran 30 minutes and off for 3 hours and it had a selector switch for weather it was summer or winter mode and made it very easy to switch mode just switch to the other mode and power up the micro controller and have changed modes

Yes I did have to write the routines and had to understand how to control the time ic chip and used an green LED light as the sensor to see if the sun was out playing and figure out how to have two different modes for the summer and winter but the most important consideration was that I did not want to have reset the timer for any reason for example power outage time change this was the motivation behind this project when I started the problem that I was having with the pool pump running I wanted a solution that I could setup and not worry about except for two times a year and all I needed to do was power down the micro controller and and flip the selector switch and power up the micro controller and was back up and running again

LOVE this idea and thank you for the detailed explanation...

I do have a quick question though. This item (and I could just use it as a launch point for my search) seems to feed a lot of power to heaters for a water tank/aquarium...? The fans I am thinking to use are less than 1 amp. I would be willing to go as high as say,,, 2 amps, but 10 amps? Seems like a lot for my application. No?

Honestly, I would prefer to just have a timer switch that turns on (is switchd) when the hot water pump turns on,,, and then remains on for a set time once the pump turns off. Is there something like that out there that will feed low amperage and 12v to small fans like the ones I have?

[sam_sam_sam]

The problem you are going to run into is when your boiler gets to cold you will be defeating the purpose of what you are trying to do you a temperature controller to shut off the fan when your boiler is not producing heat now you could run the pump with out the heat on and use that heat but you still need to have way to cut off the pump when the water temperature is too cold to do any good

I think you are over looking this fact if try to run the way you are describing it you will be blowing cold air once the pump turn off

[JayPoorJay]

Sam. It's a radiator. They stay hot for 10, 20, 30 min or longer (considerably longer) when the boiler/pumps shut down. What I would like to do is have 2 small computer type cooling fans run for 15 or 20 minutes AFTER the boiler has run a cycle. The on off of the boiler is responding to temps FAR away (and warmer) from this cold room (the kitchen) in the house.

Am I posting to the wrong sub-forum?

Also, the boiler/furnace AND the pump would not change the way they function in anyway what so ever. The only thing that would be happening is that during a ON/RUN cycle, as is normal, the furnace and the pump would be triggered by the thermostat. The triggering of the pump (or some other circuit )would ALSO trigger the fans. When the boiler/furnace AND the pump turn off (if I could just get some help figuring out the switching) the fans would continue to run for 10 or 15min or so, what ever time would be best.

I need some help figuring out the switches. And the timer. What part is over thought,,, if you don't mind?

[sam_sam_sam]

Okay what you need is cycling timer that extends the off time something like this “ 38247-RLAdjustable Recycle Timer 110/220VAC “ here is where you can find one

https://www.mpja.com/SPST-NO-Adjusta...info/38247+RL/

You would use this mode “Timed Startup: Adjustable (Delayed Turn ON on Trigger “ or the “Delay Turn Off” mode it depends on how you want it to function one might work better than the other one

How you would use this is set the amount of time you want it to run after the pump stops running however you would need to change the pump relay if it does not have a normally closed and a set of normally open set contacts with a common terminal this need to run the timer or they can be an isolated set of each would work but you would need to add a jumper wire to the other set of contacts

Now you might need to change the main power line to the common terminal on the relay if it is not setup this way already

You could also use just a cycling timer but you would still need a set of normally closed contacts that are not connected to the main power lines THIS is very important thing to remember if you are using a dc cooling fan needs to be isolated from the main power line and you use a power supply that is rated for the cooling fans that you are using

If you use a dc timer module you might need to try different ones because not all of them works the same way and some of them are not recycling type some what called a one shot type timer which means that you would need to power cycle it for it to start timing again this might work for you but you would need to experiment with the one you choose to see if works the way you intended for it to work