Replacing a furnace

[asti]

We want to replace a 75K furnace with a 125K -

Was told by the HVAC place we called to install it, said our square footage is too small (608 with uninsulated crawlspace) for this 125K and we would "burn it up" by it cycling 'too shortly'

A few friends of mine say this is just an excuse, cause they don't want to install a unit that wasn't theirs to begin with...............

Any input?

Thanks

[Guest ahammer48]

Hello

Just making sure. The square footage U want to heat is 608sq/ft? If thats correct then what U were told is true. The 125k is why over kill. U may not burn the unit up but it will be toatally in-effiecent 4 U. Is this a wall furnace(no fan) or do U use a fan to blow the air around?

Why do U want to increase the output so much? Is the area staying cold? Whats the problem? If this is just a replacement due to age and U'd like alittle more heat up the new unit to an 85k output.

Hope this helps:)

[asti]

Thanks for replying ahammer48,

What happened was this:

In 2003 I bought this 'cabin' of 608 ft. (OLD and poorly insulated, single pane windows,  crawlspace, propane as fuel.

The furnace that was here I had checked out, a Janitrol 75K, however, I was told it needed replacment as the heat exchanger is cracked, and not to use it.

Since this joint is so small, eventually it will be replaced with a real home, so not interested in doing anything in the way of upgrading.

Heated with wood last year. Prices from sources in our area are now 50.00 per load, which would net 100.00 per month on heating - bad venture.

Thought of replacing the furnace and happened across this Heil ( and since the new place WILL be bigger, bought it as it is in great shape )

Asked about having the Heil installed and was told it was too big & would burn itself up, but as I said, I have been told this might be an excuse.

It is a downflow with blower. I would add an open vent under the crawlspace where the water pipes are, to avoid having to use the electrical tape as in the past.

If I can utilize this Heil 125K without damaging it, I would like to do so.

[hvacdrd]

I realize this will not be the answer you are looking for but it is as honest of an answer I can give. You asked so here goes...

Think of it this way...would you put a 454 CI engine in a Yugo? And here is the catch, the engine is either full throttle or off. Sure it would get you around town if you were fast enough with the ignition switch. Does it work - yes. Is it the most logical mode of transportation - probably not.

Your 125K heater is no different, it is designed to heat a home 4 to 6 times the size of this cottage (depending on efficiency rating).

So here is the deal, if (and it is a BIG if) you absolutely want to use it then here are a couple of suggestions. Mind you this will not be very efficient to utilize. Make sure you have plenty of return air and as many supply air registers as you can to get all of this heat away from the furnace (or you WILL crack the heat exchanger). Find out from the manufacture if you can derate the furnace using smaller orfices and lower manifold pressure. Finally make sure the temperature rise is in line with manufacture rating plate, if not you will need to add even more registers.

Be prepared for very short heating cycles, quick temperature swings and the strong possibility of acidic condensate rusting out the heat exchanger and vent piping simply due to the fact the unit will never run long enough to stabilize.

As for the heating dealer "excuse" he is simply not willing to install the wrong size furnace regardless of who supplies it - it is a huge liability and defies logic.

[asti]

Thank you very much, this explaination indeed made quite a bit of sense.  More thought needs to go into it.

[asti]

How would adding to the duct work, and sending it out to the well pumphouse sound?

The pumphouse is roughly 7 or 8 ft (X4) not sure on distance from house..........sound silly or what?

Flexible duct work or regular a better bet?

Might just not worry about anything here and waste $ on fire wood again this yr, sigh...

[asti]

Got pricing info, 50.00 bucks (thereabouts) for the additional ductwork, less if I use the flex type.

I also saw a nifty mini-blower that helps push along, about 25.00.

I dunno, seems like an OK option, huh?

[hvacdrd]

Just a thought - can you get the model and serial number of the Janitrol with the cracked heat exchanger? Most manufactures have a 20 year warranty on the heat exchanger - Goodman(Janitrol) charges $50.00 handling fee. I think this would be a better option for your money. You will have less labor time and less money out of your pocket. More importantly it will operate much more efficiently for your setup.

[asti]

FDS80-55 number 157C0097  ( not really sure what is what here, lol

thermostat is new, replaced last year

nice idea! THANKS

[Guest ahammer48]

Hello

Sorry Dude. Theres no easy solution to what U have in mind. Forget the pump house. You'd only B making it nice and warm for critters.

Adding the crawl space will help, if it runs under the entire house, but your still short sq/footage and again, critters love a warm space.

Heres a suggestion. Use electric oil filled baseboard heaters( put them under the window) in each room and use them along with your wood burner( stove??) The heaters are cheap enough, and U wouldn't be just dependent on wood. Not knowing what U pay for a kilowatt dosen't help me, but U could use the wood during the day when electric rates are usually higher and then run the heaters at nite when rates are usually lower.

This isn't a long term solution. If its gonna B awhile till the "house " is built U might want to think about a gas fired wall heater(has no fan, works by convection). There cheaper and since this is a cabin U propably don't have many seperated rooms. There decent for doing 1-2 large areas.

Save the heil untill Ur ready 4 it

Hope this helps:)

 

[asti]

Ah, Dudette in this case,

but, smarter than the average bear, wether or not its feasible is of course, anouther question!

Have indeed thought of the ventless units, cheap, easy to obtain, easy to run lines....

was looking for the "all over" advantage..........

1) Wall unit Pros:  see above, lol

Cons: location, not really a good place for one or two to BE mounted.......

          still have to run the heat tape on the pipes under the house, and heat lamp in    pumphouse

2) replace furnace with same BTU......not feasible $$ wise, nor future ventures, house WILL be replaced very soon!

3) Use the 125K furnace:

pros/cons :

have to extend venting, add some in and out

save on electric bill  (already 60.00 per month

won't have to run heat tape on pipes under house, nor the heat lamp in pump house)

4) leave it all alone and use wood

pricey, heavy and troublesome,  still have to use the heat tape and lamp

also, add the blower fan on wood stove to move the air, as well as the ceiling fan for electric bill

5) repair/replace some parts in the current 75K furnace

Unit has NOT been "shut down" or tagged, there are a few cracks, but the service fella said it was indeed OK to use, but highly encouraged replacement, but said do not try using it longer than a year or two, without having it checked out compeletly everytime.

 Company has excellent reputation in this area as well as BBB

Or use as is, after a check up.........

Like I said this is a temporary quick fix, for this winter, just dont want to ruin the 125K furnace.

Thanks heaps, yous guys here are the Bees Knees................

[hvacdrd]

Dudette...

No hit on the model number yet...still waiting for a reply from a supplier.

If you do decide to use the 75K as is - be sure to have a CO detector in the cabin and make sure the burner box is equiped with flame roll-out switches (would be there already from the manufacturer).

Not sure if they explained why a cracked heat exchanger is bad news. Two concerns, combustion products getting into the living space(Carbon Monoxide)and fire hazard when flames roll-out of combustion chamber.

Just curious, where is the general location of this cozy cabin?

[asti]

If I need to hunt more numbers up I can certainly try, thanks for your extra efforts!

In central IL, cozy only in size, lol

I have a call into the HVAC shop previously called, and the fella said he would call me back before the weekend to discuss plans, up to and including the throttling down of the furnace.