HoosierBuddy
Well-known member
Hey guys....just thought I'd post a little info on this week's project for your amusement.
SO...issue is when we bought this 100+ year old farm house I live in 25 years ago (Hell...it was almost new back then!)...the kitchen was so small that we had to bust out an exterior wall and combine the enclosed back porch into the kitchen to create a spot for the kitchen table.
Well as you can imagine...this back porch wasn't entirely "up to code" or "Insulated" or had "Thermopane glass"....so it took years honestly for me to get all that straightened out to make the building envelope reasonably secure. But even after all that was taken care of, you're still talking about a room with 3 exterior walls, huge windows, an exterior door also with a huge window, a cathedral ceiling and skylights.
To heat this area, we were able to add one heat duct, but the only way to route the duct under the floor joists was to use a single piece of flex duct (6 inch id), bust out a couple of blocks between the low crawl under the porch and the house's basement and hook that flex duct to a long run of existing duct. So the porch vent is by far the furtherest vent from the furnace.
Did it work? Not really.
Not really to the point that when we added our garage addition with hydronic heat in 2006, I added a t-stat and zone to the set up, along with two small hydronic heaters (coils with fans that kick on automatically when the zone pump kicks on) to get some heat at the kitchen table.
Did that work. Yes. Adequately.
But...you know....still not great. So, several years ago I added an inexpensive duct booster fan to see if that would help. It went in the flex duct where it hooked into the existing piping and was wired all the way back to the furnace so if there was a heat or a/c call it would kick on.
Did that work. No. Not really. There was still almost no air coming out of the duct and the fan was loud, and quit working after about a year, and I didn't even bother fixing it.
So...this week I got back into it and bought and installed:
https://www.amazon.com/gp/product/B07FPFVZTZ/?tag=atomicindus08-20
A 6" variable speed duct fan that seems to be popular among the "home grower" crowd.
And this:
https://www.amazon.com/gp/product/B01KEYDNKK/?tag=atomicindus08-20
A temperature controller that monitors a remote temperature probe and energizes one of two 120 V outlets based on the temperature of the probe and what you've programmed the unit to do.
Did this work?
Absolutely. This thing kicks on and blows enough air through the duct I had to clean the kitchen table off after the dust settled from the test run.
How I installed it was to put the duct booster fan in the basement right where the flex duct tees into the old hard duct. I drilled the hard duct upstream of that for the temperature probe. I plugged the booster fan into the COOLING outlet on the Temperature Controller (for heat...I know that's counter-intuitive) and set the controller to look for 90 degrees F with a "Cooling" offset of 5 degrees F. When it runs, what happens is, the temperature controller is monitoring the duct temperature and trying to keep it under 90 degrees. So....the furnace kicks on and once the duct temperature rises above 95 degrees....the controller kicks the fan on, and it will stay on until the temperature in the duct drops below 90 degrees.
As long as the burner on the furnace is running the temp can't get below 90....so the booster fan just keeps on running until the heat call is done and then runs until after that until the duct cools under 90.
It actually works so well that I set the variable fan speed on the duct booster down to about 50% because on high it blows more air than I want or need.
Right now I've got all this sort of temporaried...so my weekend project is to mount it permanently.
Anyway....this is a years long head scratcher for me that has always been one of those "there's gotta be a better way" issues that I'm about ready to call "fixed" so...you know.... whoop whoop and whatnot.
Phil
SO...issue is when we bought this 100+ year old farm house I live in 25 years ago (Hell...it was almost new back then!)...the kitchen was so small that we had to bust out an exterior wall and combine the enclosed back porch into the kitchen to create a spot for the kitchen table.
Well as you can imagine...this back porch wasn't entirely "up to code" or "Insulated" or had "Thermopane glass"....so it took years honestly for me to get all that straightened out to make the building envelope reasonably secure. But even after all that was taken care of, you're still talking about a room with 3 exterior walls, huge windows, an exterior door also with a huge window, a cathedral ceiling and skylights.
To heat this area, we were able to add one heat duct, but the only way to route the duct under the floor joists was to use a single piece of flex duct (6 inch id), bust out a couple of blocks between the low crawl under the porch and the house's basement and hook that flex duct to a long run of existing duct. So the porch vent is by far the furtherest vent from the furnace.
Did it work? Not really.
Not really to the point that when we added our garage addition with hydronic heat in 2006, I added a t-stat and zone to the set up, along with two small hydronic heaters (coils with fans that kick on automatically when the zone pump kicks on) to get some heat at the kitchen table.
Did that work. Yes. Adequately.
But...you know....still not great. So, several years ago I added an inexpensive duct booster fan to see if that would help. It went in the flex duct where it hooked into the existing piping and was wired all the way back to the furnace so if there was a heat or a/c call it would kick on.
Did that work. No. Not really. There was still almost no air coming out of the duct and the fan was loud, and quit working after about a year, and I didn't even bother fixing it.
So...this week I got back into it and bought and installed:
https://www.amazon.com/gp/product/B07FPFVZTZ/?tag=atomicindus08-20
A 6" variable speed duct fan that seems to be popular among the "home grower" crowd.
And this:
https://www.amazon.com/gp/product/B01KEYDNKK/?tag=atomicindus08-20
A temperature controller that monitors a remote temperature probe and energizes one of two 120 V outlets based on the temperature of the probe and what you've programmed the unit to do.
Did this work?
Absolutely. This thing kicks on and blows enough air through the duct I had to clean the kitchen table off after the dust settled from the test run.
How I installed it was to put the duct booster fan in the basement right where the flex duct tees into the old hard duct. I drilled the hard duct upstream of that for the temperature probe. I plugged the booster fan into the COOLING outlet on the Temperature Controller (for heat...I know that's counter-intuitive) and set the controller to look for 90 degrees F with a "Cooling" offset of 5 degrees F. When it runs, what happens is, the temperature controller is monitoring the duct temperature and trying to keep it under 90 degrees. So....the furnace kicks on and once the duct temperature rises above 95 degrees....the controller kicks the fan on, and it will stay on until the temperature in the duct drops below 90 degrees.
As long as the burner on the furnace is running the temp can't get below 90....so the booster fan just keeps on running until the heat call is done and then runs until after that until the duct cools under 90.
It actually works so well that I set the variable fan speed on the duct booster down to about 50% because on high it blows more air than I want or need.
Right now I've got all this sort of temporaried...so my weekend project is to mount it permanently.
Anyway....this is a years long head scratcher for me that has always been one of those "there's gotta be a better way" issues that I'm about ready to call "fixed" so...you know.... whoop whoop and whatnot.
Phil