Advice Please: AA 130 With Heat Exchanger Installation

The main item I am looking for is the plenum water to air exchanger.
Im gonna get a quote from a local distributor in the AM.
But also interested and open to ideas others may have on the project I am about to begin.
piping for underground, do's and dont's. It will be a low budget project of course, we plan on having this unit in operation for next winter. And if I move in five years as my wife is demanding, I will be taking the boiler and plenum exchanger with me to the next place.
I'm in the process of acquiring an A.A.130, Current furnace is 90+ propane forced air, with A/C coil on top Upflow unit. If you check the picture out there is not much room above the A coil before the duct work goes off to the right along the ceiling of the basement and through a Skuttle Humidifier. This is an old farm house, didnt know if someone new how I could squeeze it in there with out to much alteration. I do know I could just hang the unit on its side, but little more labor than planning on, Propane would be a back up heat source. And I dont think the new plenum heat exchanger should be in the return because that would possibly heat up the blower too hot?. Im planning on installing the A.A. in the detached old summer kitchen. This will require some fixing up of course it is run down but has a good shell and chimney. Let the project begin.

Look on eBay, that's where I got the heat exchanger for the EFM.

I'm going to move this topic to a more appropriate spot on the forum.

Depending on the size exchanger you need, you maye have to put in your return duct, if you dont have the room for it in the supply duct

The blower motor draws the hot air into itself on mine, and I have not had any problems(so far,knock on wood) with the motor. My fancoil came in it's own insulated plenum, and is rated for 130,000 btu's.

Thanks, big push in the right direction. Heat exchangers are not as bad as I thought. And only four inches, might be able to make that work if not I could try it in the return. 80000btu coil now the question is cfm's. Nordyne blower may have to play with that once it's up and running. I'll probably answer allot of my own questions once installation begins. I think i saw some one saying a special stat to make the blower come on once the coil is hot, and what about a high /low limit switch. Over kill? Also how would the backup heat propane over ride this switch or stat? Ah new thermostat duh! 2h1c. Sorry folks don't know until you walk yourself through it.

Frytown wrote: I think i saw some one saying a special stat to make the blower come on once the coil is hot,

That would be me, the aquastat that is at the top of the picture. I have 2 thermostats, 1 for the heat pump a/c, one for the coal. The aquastat is on the wire that goes to the squirl cage fan motor, the aquastat makes on temp rise when the bulb gets hot that is straped to the fancoil. I have a switch on the thermostat to run the fan all the time, and the aquastat on the fancoil makes and breaks so the fan only runs when the fancoil is hot. This way I did not have any electric backfeeds between the 2 systems, The HEAT alone tells the fan to start and stop.

Well I went a little different direction with my setup so I'll tell you about it for another point of view. I had a limited amount of room like you with an A coil for A/C and a down flow furnace. What I ended up doing is buying a second hand air handler (2 ton) and building a plenum and filter rack for the new 80K coil. I plumbed that into my existing runs.

The coil is hot 24/7 and the seperate T-stat operates a relay which turns the fan on. Propane furnace is there for backup on it's own T-stat and doesn't come on.

The biggest benefit is the fan turns slow and doesn't blow a huge amount of air like the forced air Propane does. Now my floors are warmer and everything in the house is warmer as well. I liken it to a stove in that it heats slowly so everything gets warm versus the hot/cold forced air cycle where you're always cold the minute the fan stops.

I picked up my heat exchanger from CTwoodfurnace I think. Price was right on the 80K in the house and the 100Kbtu in the garage. Also heat my water with the AA130 and it just plugs along.

I sat the heat exchanger on the outlet of the oil-fired hot air furnace. That way I'm not wasting any BTU's heating up the insides of the furnace. In the plenum above the exchanger I placed a salvaged Honeywell blower switch. The furnace blower is wired through a switch, one side is for the oil burner controls, the other is connected to the Honeywell switch. On a call for heat the exchanger gets hot, the temperature switch closes and we have heat.

I'd suggest using a heat exchanger with a larger footprint than the duct. They are restrictive and by using a larger one with more air passages, you lesson the impact.

Can't tell by the pic, but maybe move the scuttle downstream and sneak the coil in vertically?

Fyi, I have a 3 ton heat pump that serves 1700 sq ft of space. Heat pump unit is locked out with heat in the boiler, via an aquastat. My coil is a double pass 30x15". It'll give heat even at low water temps [120* water = 80* air from duct].

I have a scuttle like yours too [love it], just downstream of the coil. Install is crowded, there are turning vanes that steer the air both ways inside the tee that the scuttle's water grid barely clear.

Dave

Well Drove through the sleet/ rain storm and picked up the '57 A.A. Now that I have the Heart of the project here, it is time to save a few coins to give it a good once over and hopefully this summer Ill get to fire it up. I really like the ideas so far folks, Probably wouldn't have come up with a few of them. Don't really know yet what I'm going to do the aqua state idea isn't bad. And the other one explains why we keep heat on a low speed setting. Never really thought of it that way. Longer run times though would certainly occur. I've programmed my Honewell thermostate to only come on twice an hour. This probably justs increases the spread on the on and off temps , because Most of the time when its cold it will still kick on three maybe four times.
Keep em flowing! Ill post a pic when I get to a computer, currently on phone

'57,that was a good year for chevy's too. Is it a refurbased unit ? Can I ask how much mucho dinero ? Was it steam or hot water. ? The places where they fail are at the bottom where the burn pot meets the asher and the domestic coil flange. Sounds like you have alot of work ahead.

Frytown wrote:Well Drove through the sleet/ rain storm and picked up the '57 A.A. Now that I have the Heart of the project here, it is time to save a few coins to give it a good once over and hopefully this summer Ill get to fire it up. I really like the ideas so far folks, Probably wouldn't have come up with a few of them. Don't really know yet what I'm going to do the aqua state idea isn't bad. And the other one explains why we keep heat on a low speed setting. Never really thought of it that way. Longer run times though would certainly occur. I've programmed my Honewell thermostate to only come on twice an hour. This probably justs increases the spread on the on and off temps , because Most of the time when its cold it will still kick on three maybe four times.
Keep em flowing! Ill post a pic when I get to a computer, currently on phone

You diden't happen to buy that off craigslist did you??? for say maybe 600.00??? Just curious.

I'm running a 16"x18" coil that I purchased off Ebay from a seller just up the road in Wisconsin. Price was great and it's a high quality piece - not sure if the actual manufacturer, but the carton was made in Texas and there is a coil manufacturer down there.

It just fit between the top of the A-coil and the takeoff for the humidifier, and required a little "tin-bashing" to make the coil fit in the plenum - basically a size-on-size "press fit".
It does restrict the airflow a little bit, but the temp. rise through the furnace when on gas is still well within limits. I plan to pull the HX out and cap the plenum opening in the summer as the fan already has enough difficulty pumping sufficient cold air up to the 2nd floor.

I am feeding average 160 degree water in, and 140 out. Air into the coil is 78 (the humdifier flow warms the air a bit), and 125~130 out. The output air when running gas I measured at 138, so I'm very happy with the coil performance.

pic from when I picked it up. As you probably already know, by the pics it was cold so of course I am planning on either repairing/building the domestic coil, or getting a new one. Keep my fingers crossed that its not as bad as I think it is: Air goes in, doesn't come out the other side? hummm, must be busted copper. Maybe this week Ill take some time to investigate further.
I do believe I have come across a great deal of help lately thanks to the forum here. Even found an over-sized heat exchange coil. Looked at the propane furnace again tonight, its 120000 btu furnace, bigger than I thought it was. I checked my fan speed out as well, it was on low. Moved it up to medium-low, big big difference in the warmth of the house. I guess the low speed would be great if the exterior walls had normal insulation instead of three stackes of plastered brick. On low the core of the home seemed to be cold as soon as the furnace turned off.