Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
Sounds like interesting idea but you might want to consider two, do some research on thermosyphon loop. That's how they do it with coal stove to supplement domestic hot water in gas/electric hot water heater but it's a slow and steady process. It will circulate naturally but in your case I'm not sure if you're going to have enough heat to get it to circulate. Of course you could use a small circulation pump.
Two key things, the vessel where you want the hot water to flow too needs to be above the one that you're pulling the heat from. You'll want to keep the distance between them as short as possible. So what you would do if you had two radiators is you'd have a pipe running from the top of the one with warm air to the top of the cold radiator. On the bottom of the cold radiator you'd have another pipe running to the bottom of the warm radiator.
In a nut shell the hotter water will want to go up and force its way into the top of the cold radiator. The colder will be forced down creating a natural loop of circulation. It works on coal stoves but again I don't know if you'll have enough heat.
I already have a woodstove heating water, that is being pumped into a thermal-storage tank, and then through our radiant floor loop.
This heat-recovery-ventilator that I have seen in operation has no loop, no circ to it. It is a single radiator.
This heat-recovery-ventilator that I have seen in operation has no loop, no circ to it. It is a single radiator.
I understand that but without a loop and two separate units for hot and cold I don't see how that is going to work. The heat will rise in the radiator but it's going to be mixing with the cold... Themosyphon is almost the same principal and doesn't require powered circulation but I don't know if you'll have enough heat to get it to work.
Here is how it is set up on coal stove, you could apply this to wood stove too:
Since the coil is so short it can't do instant heat, as the water heats inside the coil in the stove it will naturally circulate into the top of the hot water heater. There should be insulation on the top tubing in second picture. The bottom loop provides a cold water return. You should be able to get all the domestic hot water you need from a setup like this if you don't use a lot of hot water.
------edit-----
Just to clarify, what I'm suggesting is you have one radiator for the iar going out. That would be like the coil in the stove to suck up the heat, your second radiator would be for the one coming in and would be like the hot water tank. It might work and I would certainly think it would work better than what you have in mind because you're providing a loop and separating the hot from the cold. This doesn't always work that great even on a coal stove but the higher the hot water tank is and providing it's short distance it will.
Last edited by thecoalman; 10-20-2009 at 06:11 AM..
We will try what we have seen and see if that works for us.
Our woodstove has a lower fire-box and an upper or secondary combustion chamber. That secondary combustion chamber is wrapped with 50' of copper tubing to heat water.
If the single radiator is set at a 45 deg angle as you look at the front the bottom tank serves as the hot source and the top tank the cold. Water would naturally rise through the oval pipe on the upper hot side and cooler water flow down on the down side. Just separate the warm air from the cool air with appropriate duct work. Also provide a way to carry off any condensation when the whole thing gets below the dew point temperature.
OK, so now our homes are built so tight that we have to provide some sort an expensive mechanical makeup air unit costing thousands of dollars ? All while using up our nations precious resources at the same time? Why not open a couple of windows for a little cross ventilation ? No way, thats not green. LOL
We have quite simply defeated the purpose of building homes tighter, or is that greener, for improved efficiency.
Why not build houses like they used to in the old days with two foot thick walls? I used to live in a house like that with single pane windows and poorly sealed doors in an extreme climate. Year round indoor temps were nearly constant with very little need for heating or cooling. Oh and uh, plenty of fresh air.
New homes should be tight and they should have mechanical makeup air. In our neck of the woods, an ERV or HERV on a new home will run you about $1500 while providing you with clean air and energy savings at the same time. How much are granite countertops in a new home? How about those nice blinds or the latest stainless steel appliances? New homes in general, are MUCH more energy efficient then older homes without the need to spend a lot in money and natural resources to build "two foot thick walls".
There is a growing problem with our newer , tighter homes producing indoor pollution. Not only do many building materials leach out some toxins over time, but all the chemicals we introduce in cleaning and air freshening components can irritate our systems if not filtered out.
We have a 2400sq ft house, it is new and tightly sealed.
We do have humidity issues.
We were advised to consider a 'heat recovery ventilation system'.
A local engineering firm that designs and installs these systems, did come to our home. They took lots of measurements and a week later sent us their estimate.
$8,000
This would include the basic 'heat recovery ventilator', fans, and ducting to each room.
I have since googled and read a bunch of customer reviews. It seems that these are the newest thing in brand new homes. The engineers say that it is needed by code for tight homes. However among customers they say that running it runs up their electric bill, and none of them can notice any difference with them on or off. So usually they end up being left turned-off.
I have seen one system in a restaurant, that is home-made. They used an automotive radiator. They ducted incoming make-up air to flow through the top of the radiator [the top half], and exhaust air to flow out through the bottom half of the radiator.
Saying that the exhaust air would somewhat heat the bottom of the radiator. The heated water would rise. The incoming cold air would be preheated as it flows through the top of the radiator.
Total cost about $200.
To be entirely honest here, I can not testify it is works. I have not installed such a system, yet.
I do have a huge radiator sitting here though, and I am collecting the bits and pieces. It is my intention of building such a device this winter in our home.
Wow-$8000 for a heat recovery system.I was going to ask about those, especially as we have one side of the house that benefits from solar gain, and another that gets virtually no sun at all (bedrooms mainly). maybe you can have a reduced system ie less ducting so not all areas included?
Radiator idea sounds interesting.
The key to a successful GSHP is installation of the ground loop. Make sure whoever does that has it properly sized and has a track record of successful installation. The technology is quite good. I would visit and talk with home owners who have used the contractor in the past.
Thanks. Not sure how easily I will find contractors in NC, but I will give it a shot.
There is a growing problem with our newer , tighter homes producing indoor pollution. Not only do many building materials leach out some toxins over time, but all the chemicals we introduce in cleaning and air freshening components can irritate our systems if not filtered out.
I think this is why they install recovery systems that have filters in.
New homes should be tight and they should have mechanical makeup air. In our neck of the woods, an ERV or HERV on a new home will run you about $1500 while providing you with clean air and energy savings at the same time. How much are granite countertops in a new home? How about those nice blinds or the latest stainless steel appliances? New homes in general, are MUCH more energy efficient then older homes without the need to spend a lot in money and natural resources to build "two foot thick walls".
Mike
Couldn't have said it better.
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
