Would you???

[<kjpro]

Ever install an air conditioning coil on the top of a counterflow furnace?

[lp13-30]

It would be OK-- if the furnace was electric.

[Joseph]

Yes and the HX lasted the life of the furnace with no problem (Trane), but I would still not recommend ever doing it that way.

Joseph

[The Freon Cowboy]

ive seen it done, and it didnt cause any problems, but i wouldnt unless there was simply no other way, and that there was plenty of filtration in front of it

[Zephyr]

I believe I saw an American Standard once that had a horizontal coil on the return side of a gas fired heater. I thought it was strange, but I wasn&#39;t there to redesign the whole thing.

[<kjpro]

Ok folks, the reason I asked is because I came across a unit that had just this set-up.

It was a downflow furnace that someone installed an evaporator coil directly on top! The furnace was an inch wider then the coil, so they bent one of the lips on the furnace. Then literally set the coil box on top. No filters or any return plenum!

The coil was so filty that &#39;of coarse&#39; the coil froze and dripped down on the dircuit board and transformer. Ooops!

He wanted cheap and that is exactly what he paid for!

[The Freon Cowboy]

sounds like a real mess , like i said earlier ive seen it done , not very often, but every instance ive seen has had a plenum and plenty of filtration before it

no reason it wouldnt work i guess , just kind of bassackward

wrote:

[Joseph]

I have seen many an upflow do the same thing... No filters at all?

[<kjpro]

Nodda, just an open coil top!

[Zephyr]

Not to be a party pooper ~

UMC of California & [Uniform Mechanical Code 2001] #905.0 "A furnace shall not be installed on the discharge side of a refrigerant evaporator or other air-cooling coil unless the furnace is specifically listed for such use. A furnace shall not be installed on the discharge side of an evaporator cooler unless the heat exchanger is of approved corrosion - resistant material."

"A refrigerant evaporator or other air-cooling coil may be installed in the air-discharge duct of a heating furnace if the furnace is listed for use with an air -= cooling coil is listed for operation at least 0.5 inch water column [124pa] static pressure and conforms with Chapter 11 of this code. Conversion of existing furnaces for use with cooing coils is permissible if authorized by the manufacturer and approved by the Administrative Authority."

Also #1114.4 - "Evaporators located within 18 inches of a heating element or coil shall be fitted with a pressure - relief device.

Exceptions: 1. Self Contained equipment. 2. Factory - built coil assemblies specifically designed for installation on the discharge of forced air heating units. 3. If the connected and unvalved volume of the low side of the system meets the following: [formulae for calculation given] 4. Reheat coils using the refrigerant for heat recovery.

Also in the code, is another section that requires a minimum filtration as well.

[The Freon Cowboy]

do you really think he gives a flying f*ck about california mechanical codes ?

whats that got to do with the price of eggs in alaska ???

hes in international waters , bwahhahahahahahah

"Zephyr" wrote:

[The Freon Cowboy]

?4øwhats that got to do with the price of eggs in alaska ???