Running a heat pump and coal stove simutaneously

Running a heat pump and coal stove simutaneously

PostBy: wileys53 On: Tue Dec 21, 2010 12:46 am

Does anyone have any advice on how to run a coalstove and a heat pump simutaneosly?
I have a 90000 btu coal stove as well as a newly installed heat pump unit in a 2600 sq ft home. I am just trying to figure out the best combination on how to run them both, thanks.
wileys53
 
Stove/Furnace Make: Keystoker
Stove/Furnace Model: Hearth 90000

Re: Running a heat pump and coal stove simutaneously

PostBy: blrman07 On: Tue Dec 21, 2010 7:25 am

Hmmm... We need a bit more information before the comments can start. What size heat pump? house layout? Manufacturer of stove? How's it installed? Where is it installed? that should be enough to get things going.....
blrman07
 
Hand Fed Coal Boiler: Bucket a Day
Hot Air Coal Stoker Furnace: Leisure Line Econo 1 stove
Coal Size/Type: Rice in the LL and anything that will fit in the Bucket a Day. It's not fussy.

Re: Running a heat pump and coal stove simutaneously

PostBy: Yanche On: Tue Dec 21, 2010 7:35 am

Heat pump off. Furnace blower on to distribute heat.
Yanche
 
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea


Re: Running a heat pump and coal stove simutaneously

PostBy: wileys53 On: Tue Dec 21, 2010 9:00 am

Thanks for your replies.
House is 2 floors with a crawl space. Half of the floor plan is open with 18' high ceilings.
Duct work runs throughout the underneath of the house with registers in the 1st floor and duct runs up through the walls to the second floor. The heat pump is a 4 ton, 16 seer 2 stage unit with a variable speed air handler.
The coal stove is on the 1st floor and is a Keystoker, 90000 BTU Hearth model.
Also there is a large, 72'' ceiling fan hanging from the middle part of the 18' ceiling above the coal stove.
I think this should do it, thanks again for your replies!
wileys53
 
Stove/Furnace Make: Keystoker
Stove/Furnace Model: Hearth 90000

Re: Running a heat pump and coal stove simutaneously

PostBy: blrman07 On: Wed Dec 22, 2010 9:12 am

set the thermostat for 60 for the heat pump and run the keystoker. If the house is "tight" you may need to leave the " manual windowstat" at the farthest point in the house part way open to allow fresh air in the house. The stove will suck fresh air and it will need air movement so you can get the best operation from the stove. Start there and let us know how it goes.
blrman07
 
Hand Fed Coal Boiler: Bucket a Day
Hot Air Coal Stoker Furnace: Leisure Line Econo 1 stove
Coal Size/Type: Rice in the LL and anything that will fit in the Bucket a Day. It's not fussy.

Re: Running a heat pump and coal stove simutaneously

PostBy: brucefenster On: Sat Dec 25, 2010 11:29 am

I have a hand fired Brunco 190 and have been running it tied into the same air circulator the heat pump uses. I've been running this combination for about 15 years and the system has evolved.

First thing you need to have is an understanding of the heat pump and how it works. I have a slim working knowledge of the system and will explain it. I'm sure someone else could do a much better job.

The heat pump works by extracting heat from the air. Think of an air conditioner but installed backwards in the window. In heat pump has a pump and a refrigerant gas. The gas the gas is cooled and or heated depending on if your heating or air conditioning and the process turn from liquid to gas or gas to liquid. In on case it heats the indoor coil in the heat exchanger for heat or cools the coil for air conditioning. And just like air conditioners it has to cycle on and off to keep from freezing.

Now here is what we have to understand. If your thermostat calls for head and the heat pump sends hot refrigerant into the air exchanger the pump is designed to have that refrigerant returned to it cooler than when it left the pump. If we also heat the air with another source like a coal stove, the returning hot refrigerant MAY ruin the heat pump.

So what you want to do is find the heat pump on switch and disable it but still have the air exchanger blower come on and any other controls work like zone controls you may have, while your coal stove is making enough heat to heat the house. I've done this using a thermostat control on the heat duct running from the coal stove air box to the heat exchanger. Basically over time I've discovered how hot the air needs to be from the coal stove to travel through the air exchanger and heat the house. The thermostat disables the heat pump when it's hot enough and enables it when it is to cool.

One thing I've never figured out how to fix is making sure the heat pump is not short cycled. Here is what I mean. Remember I said the pump has runs in cycle of heating (or cooling) and it cycles to insure it doesn't freeze. Well in my system the coal stove could be warn enough to have the heat pump cut out but not warm enough to fully heat the house till no heat is called for. I have 3 zones and each one could call for heat one after the other. In this case as the heat in the air duct from the coal stove to the air exchanger cools off the heat pump is enabled. As the heat pump takes over this is not a problem. The problem happens when the coal stove recovers and the heat in the ducting turns the heat pump off dead in the middle of it's cycle. I'm not really sure this is a problem but have been told it could be. Of course the heat pump is now nearly 15 years old which is a pretty good run for a heat pump so maybe this is not a problem.

Anyway I've just recently found this forum. And it seems I might have a pretty complicated system and more experience burning coal the last 20 years than most here. I may take some pictures of my system and add some more commentary later and share my experience. But right know my kids and grand kids are about to arrive for Christmas morning. Got to go.

Bruce
brucefenster
 
Stove/Furnace Make: Brunco
Stove/Furnace Model: 190

Re: Running a heat pump and coal stove simutaneously

PostBy: turbine On: Tue Feb 01, 2011 10:28 pm

I installed a heat pump thermostat that lets you program fan blower on, off time. While heat or cool are set to off. I run 3min.on/ off 30min. Moves the heat nicely. I also have a filter return grill over stove. Thermostat: Invensys 9720i fully programable, available hard wire remote sensors for outsde, and I use remote inside sensor in far cold room, a hot thermostat are would normally keep heat pump off. Unit also allow bypassing outside condenser to not come on, I set at 28 or below. auto changeover, switches from heat to cool as needed unattended. I can burn, circulate air through ducts as mentioned and HP doesn't come on. 40 outside/73 inside ,1780ft. rancher, no trees, vinyl side, good windows. I like this thermostat so much I bought a spare. Got it at W.W.Graingers .
turbine
 
Hand Fed Coal Stove: Hand fed coal stove
Coal Size/Type: nut , stove
Other Heating: heat pump, thermostat has fan only program also, distributes heat well.
Stove/Furnace Make: Harman
Stove/Furnace Model: TLC 2000

Re: Running a heat pump and coal stove simutaneously

PostBy: homecomfort On: Sun Apr 03, 2011 1:04 am

brucefenster wrote:I have a hand fired Brunco 190 and have been running it tied into the same air circulator the heat pump uses. I've been running this combination for about 15 years and the system has evolved.

First thing you need to have is an understanding of the heat pump and how it works. I have a slim working knowledge of the system and will explain it. I'm sure someone else could do a much better job.

The heat pump works by extracting heat from the air. Think of an air conditioner but installed backwards in the window. In heat pump has a pump and a refrigerant gas. The gas the gas is cooled and or heated depending on if your heating or air conditioning and the process turn from liquid to gas or gas to liquid. In on case it heats the indoor coil in the heat exchanger for heat or cools the coil for air conditioning. And just like air conditioners it has to cycle on and off to keep from freezing.

Now here is what we have to understand. If your thermostat calls for head and the heat pump sends hot refrigerant into the air exchanger the pump is designed to have that refrigerant returned to it cooler than when it left the pump. If we also heat the air with another source like a coal stove, the returning hot refrigerant MAY ruin the heat pump.

So what you want to do is find the heat pump on switch and disable it but still have the air exchanger blower come on and any other controls work like zone controls you may have, while your coal stove is making enough heat to heat the house. I've done this using a thermostat control on the heat duct running from the coal stove air box to the heat exchanger. Basically over time I've discovered how hot the air needs to be from the coal stove to travel through the air exchanger and heat the house. The thermostat disables the heat pump when it's hot enough and enables it when it is to cool.

One thing I've never figured out how to fix is making sure the heat pump is not short cycled. Here is what I mean. Remember I said the pump has runs in cycle of heating (or cooling) and it cycles to insure it doesn't freeze. Well in my system the coal stove could be warn enough to have the heat pump cut out but not warm enough to fully heat the house till no heat is called for. I have 3 zones and each one could call for heat one after the other. In this case as the heat in the air duct from the coal stove to the air exchanger cools off the heat pump is enabled. As the heat pump takes over this is not a problem. The problem happens when the coal stove recovers and the heat in the ducting turns the heat pump off dead in the middle of it's cycle. I'm not really sure this is a problem but have been told it could be. Of course the heat pump is now nearly 15 years old which is a pretty good run for a heat pump so maybe this is not a problem.

Anyway I've just recently found this forum. And it seems I might have a pretty complicated system and more experience burning coal the last 20 years than most here. I may take some pictures of my system and add some more commentary later and share my experience. But right know my kids and grand kids are about to arrive for Christmas morning. Got to go.

Bruce
homecomfort
 
Stove/Furnace Make: Franco-Belge,+ Penn Stove
Stove/Furnace Model: Normandie, + Chubby

Re: Running a heat pump and coal stove simutaneously

PostBy: homecomfort On: Sun Apr 03, 2011 1:05 am

homecomfort wrote:
brucefenster wrote:I have a hand fired Brunco 190 and have been running it tied into the same air circulator the heat pump uses. I've been running this combination for about 15 years and the system has evolved.

First thing you need to have is an understanding of the heat pump and how it works. I have a slim working knowledge of the system and will explain it. I'm sure someone else could do a much better job.

The heat pump works by extracting heat from the air. Think of an air conditioner but installed backwards in the window. In heat pump has a pump and a refrigerant gas. The gas the gas is cooled and or heated depending on if your heating or air conditioning and the process turn from liquid to gas or gas to liquid. In on case it heats the indoor coil in the heat exchanger for heat or cools the coil for air conditioning. And just like air conditioners it has to cycle on and off to keep from freezing.

Now here is what we have to understand. If your thermostat calls for head and the heat pump sends hot refrigerant into the air exchanger the pump is designed to have that refrigerant returned to it cooler than when it left the pump. If we also heat the air with another source like a coal stove, the returning hot refrigerant MAY ruin the heat pump.

So what you want to do is find the heat pump on switch and disable it but still have the air exchanger blower come on and any other controls work like zone controls you may have, while your coal stove is making enough heat to heat the house. I've done this using a thermostat control on the heat duct running from the coal stove air box to the heat exchanger. Basically over time I've discovered how hot the air needs to be from the coal stove to travel through the air exchanger and heat the house. The thermostat disables the heat pump when it's hot enough and enables it when it is to cool.

One thing I've never figured out how to fix is making sure the heat pump is not short cycled. Here is what I mean. Remember I said the pump has runs in cycle of heating (or cooling) and it cycles to insure it doesn't freeze. Well in my system the coal stove could be warn enough to have the heat pump cut out but not warm enough to fully heat the house till no heat is called for. I have 3 zones and each one could call for heat one after the other. In this case as the heat in the air duct from the coal stove to the air exchanger cools off the heat pump is enabled. As the heat pump takes over this is not a problem. The problem happens when the coal stove recovers and the heat in the ducting turns the heat pump off dead in the middle of it's cycle. I'm not really sure this is a problem but have been told it could be. Of course the heat pump is now nearly 15 years old which is a pretty good run for a heat pump so maybe this is not a problem.

Anyway I've just recently found this forum. And it seems I might have a pretty complicated system and more experience burning coal the last 20 years than most here. I may take some pictures of my system and add some more commentary later and share my experience. But right know my kids and grand kids are about to arrive for Christmas morning. Got to go.

Bruce
homecomfort
 
Stove/Furnace Make: Franco-Belge,+ Penn Stove
Stove/Furnace Model: Normandie, + Chubby

Re: Running a heat pump and coal stove simutaneously

PostBy: homecomfort On: Sun Apr 03, 2011 1:11 am

the heat pump discharge temp is about 120 to 160 degrees, depending on outside temp. and charge. so as long as your indoor temp is not about that temp, h/p will be fine. unit does not cycle off to prevent freezing, rather it reverses direction of gas, heating outside coil to defrost. at least you are honest about " your slim working knowledge".
homecomfort
 
Stove/Furnace Make: Franco-Belge,+ Penn Stove
Stove/Furnace Model: Normandie, + Chubby

Re: Running a heat pump and coal stove simutaneously

PostBy: oros35 On: Sun Apr 03, 2011 12:07 pm

I have a heat pump with the coal stove in the basement. I just leave the thermostat set at 66 during the winter. The coal stove heats up the house with the basement door open. It creates a pretty good natural curculation in the house. Usually the house furnace only kicks on a few times a day or maybe more if it's real cold out. The main part of the house we use is directly above the stove and stays 68-70, the back part of the house is 63-65 but is only the bedroom and we like it colder back there.
The heat pump will kick on if it gets too cold in the house. If it's too cold for the heat pump to work efficiently the electric coil heat will make up the difference.
Sometimes I will kick the furnace blower on low by its self to circulate the air if there becomes too big a differential. All controlled by the thermostat on the wall.
oros35
 
Baseburners & Antiques: 1912 Smith & Anthony Hub Heater #215
Stove/Furnace Make: Smith & Anthony Co.
Stove/Furnace Model: #215 Hub Heater