Need suggestions from HVAC guru's

[jkeyser14]

I just replaced my house's oil furnace and a/c with geothermal, and I kept my old oil furnace/evaporator and condenser hoping to use them in the garage without losing any floor space. Here's my dilema... The oil furnace won't fit in the attic space in my garage (4/12 roof on a 20' span and it's an upflow unit). Not to mention my trusses are a simple design with a 2x4 bottom chord and I'd be worried about the weight of this heavy old furnace up there.

I'd like to re-use the AC condenser, and if possible the evaporator (Rheem RCBA-3765GG21) as well. The evaporator section can be removed from the air handler, but the blower is built in to the oil furnace section. Ideally I would find a light weight side flow air handler that's got a blower section with an aux heating strip that I could bolt my evaporator right up to. I'm having a hard time finding anything online. I even thought about a minisplit system and just purchasing the evaporator half, but I haven't been able to find vendors that sell just the evaporator.

Can anyone give some suggestions or point me in the right direction?

Edit: forgot to mention the condenser is an r22 unit.

 

[MyDomain]

You have a 2.5-3 ton coil that is most likely a multi-position so you can turn it for horizontal use. You need to find an air handler that can move 1000-1200 cfm, depending on your condensing unit, if you give me that model number I can tell you what size it is, and then attach it on the supply end. You can use any manufacturer to blow the air, just pull the included coil out if it has one.

The other option is to find a surplus air handler that matches your Rheem condenser. It can be Rheem or Ruud, again I can tell you what the options are if you have the condenser model. Here is a good spot for surplus...https://surpluscityliquidators.com/view_product/151000/110 . We just through a bunch of R22 air handlers in the dumpster to clean up for inventory.

The mini split idea will not work.

 

[CamarosRus]

www.hvac-talk.com

 

[jkeyser14]

My condenser is model # RAKA030JAZ

 

[burleymike]

From what I can tell that evaporator does not have a TXV. When you install you might consider adding one. You will be happy with how much better it cools.

 

[Falcon67]

www.hvac-talk.com

NO DIY! Don't go there and ask for help, you'll get "call your local professional" - period.

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[jkeyser14]

Here's what I've come up with for the blower and electric heat after a little searching:

http://www.alpinehomeair.com/viewproduct.cfm/productID/453057859
http://www.alpinehomeair.com/viewproduct.cfm/productID/453062119

Any issues (besides Goodman being a cheap brand?)

 

[babzog]

www.hvac-talk.com

Those guys are only into preserving their trade secrets like the stone masons of centuries past. They're not interested in helping you and I get things done (and they'll cite "legal reasons" as their rationale). No insult to any hvac-talk guys who are also members here, but when I had some problems last year, I went there for some advice and help and was basically told to piss off and hire a contractor. Was not impressed.

Try here instead... found a much nicer crowd who would actually help out.

 

[Tool Time]

I am new here but I can help. Most cased coil can be installed vertical or Horizontally, but I am not sure about this make of coil. The one way you can tell is by looking at the case to see if there is a total of three drains with one or two plugged. If there are three plugs then most likely you can install the coil Horizontally. You can remove the one plug and move it into the drain that had been use when it was installed Vertically

But, to make sure look through the coil to see if there is a internal drain pan for the condensation to collect into while it is laying on it's side. Some cased coiled needed a optional pan installed for Horizontal installations.

Regarding the oil furnace, you maybe able to remove the burner and pull out the heat exchanger but without seeing the furnace I would not suggest that. They do make electric finances like the one someone linked for you. The cost are fair and have very little weight.

The outside unit should work without any issues, but make you the have the copper lines closed off to the weather. Actually make all the lines are taped or closed off to include the coil until you decide if you can use the units.

Let me know if I can be further help.

Dave

 

[bazar01]

If you only need the indoor unit with electric heat strips and without the evaporator, your best source will be a local hvac contractor's scrap yard. Most indoor units are taken out of service by contractors because of a leaky evaporator coil and you can easily take the old leaky evaporator out and install your good cased evaporator.

The problem in with matching the old 10 SEER outdoor unit condenser with the a new indoor unit is in the SEER ratings of the new evaporator. It will work but will not be a perfect match.

Hope that helps.

 

[enrgeezone]

I assume that the unit is a 3 ton by the model # Why don't you scrap the furnace and the coil go buy a 3 ton airhandler it is light weight is able to accept a heat kit in a variety of kw's and your trusses will be just fine with that load.... I do them all the time... the township wants the weight of the unit and manfactured truss co will give you a spec sheet being able to show the 100 lbs or so that the airhandler weighs.....remember you span at least 3 of the truses..... so much simpler and mostlikley cheaper in the long run... as for the coil being r22... they don't have a clue as to what chemical is going through them..... if it is a orfice style that you currently have match the piston size that is current to the new coil...if txv match the txv..... you could be running in a few hours for a few hundred bucks....

 

[redsky49]

Unless the equipment is no more than a couple of years old, I typically (and strongly) advise against the re-use of existing equipment. Invariably, whenever I haven't followed this rule it has come back to bite me.

In the vast majority of cases, you would be better off purchasing new. The first step however, is to perform a load calculation to see what the actual heating/cooling requirements are for your particular application.

As always,offered only as opinion

 

[jkeyser14]

I assume that the unit is a 3 ton by the model # Why don't you scrap the furnace and the coil go buy a 3 ton airhandler it is light weight is able to accept a heat kit in a variety of kw's and your trusses will be just fine with that load.... I do them all the time... the township wants the weight of the unit and manfactured truss co will give you a spec sheet being able to show the 100 lbs or so that the airhandler weighs.....remember you span at least 3 of the truses..... so much simpler and mostlikley cheaper in the long run... as for the coil being r22... they don't have a clue as to what chemical is going through them..... if it is a orfice style that you currently have match the piston size that is current to the new coil...if txv match the txv..... you could be running in a few hours for a few hundred bucks....

It's a 2.5 ton system. I am trying to do this on the cheap because I can't afford much right now, but want to make the garage a place I can work comfortably. From what I understand r410a has to be charged to a much higher pressure than r22, so it is important to know which refrigerant the system uses. Air handlers are coming up as being a couple hundred more than just the blower section, and if I have the coil and know that it doesn't leak, I figure I can try to get a few years service out of it.

 

[jkeyser14]

Unless the equipment is no more than a couple of years old, I typically (and strongly) advise against the re-use of existing equipment. Invariably, whenever I haven't followed this rule it has come back to bite me.

In the vast majority of cases, you would be better off purchasing new. The first step however, is to perform a load calculation to see what the actual heating/cooling requirements are for your particular application.

As always,offered only as opinion

I completely agree with you. A new system is going to cost me $1500 or more for parts, not including labor for the line set and charging. I can't afford that right now unfortunately, so I'm trying to get by with spending under $500. Also, my AC condenser isn't that old and was in perfect working condition. It was removed from service because we wanted to get rid of the old oil furnace and decided to go geothermal.

As for load calcs, I'm oversized by about 1/2 ton, but I don't care since efficiency isn't a large concern and I could care less about short cycling equipment that was basically free. The unit isn't going to run except to keep temps above freezing 24/7 in the winter and raise/drop the temps quickly on the occasional weekend. I also don't care about dehumidification since I rely on a standalone dehumidifier to keep my machinery and tools from rusting.

 

[enrgeezone]

I understand what your trying to do.... but I think your missing that the new airhandler doesn't know what freon is going to be in the unit....the coil will take the pressure of 410 it is not some absurd amount PSI just more than the R22 systems..... if its dollars that you want to save why not drag the heater in the garage put the coil back on it, wire it and use it for just a/c the oil burner doesn't have to be hooked up to blow cold air..... I just think that for the small amount of money you could buy a airhandler,.. install it,.. reconnect your newer outdoor unit and have many years of trouble free use.....why hack something togather that will bit you in the pants...your so close to spending the same amount of money to just do it right and be done with it..... not knockin ya just been there and done that before only to rip it out a year later and start over..... good luck

 

[MyDomain]

My condenser is model # RAKA030JAZ

For some reason I didn't get a notice you had replied, sorry. You have a 10 seer 2.5 ton ac condensor. It needs 1000 cfm of air. Due to the age I would just get an air handler that can move 1000 ffm of air and tack your cased coil onto the end of it. Cheapest and simplest solution.

Tim

 

[jkeyser14]

For some reason I didn't get a notice you had replied, sorry. You have a 10 seer 2.5 ton ac condensor. It needs 1000 cfm of air. Due to the age I would just get an air handler that can move 1000 ffm of air and tack your cased coil onto the end of it. Cheapest and simplest solution.

Tim

Thanks. That's my current backup plan. After doing some more research my primary plan is to try and sell the old equipment on craigslist for a few hundred and buy a ductless mini-split. I've got a couple people who have expressed interest so we'll see how things go.