90% plus afue furnace disadvantages?

[tc35dforme]

Haz,

Watch the drain tie in..the gas furnace condensate is quite acidic and can tear up you drainage. They have neutralization kits that may be necessary to mellow out the condensate.

Have you considered adding a zone from your existing hot water. PEX tubing can be easy to snake up and I'd bet you have the extra capacity in the boiler plant. PEX tubing, baseboard, some controls = less than all new furnace.

Of course I'm assuming A/C isn't part of the equation.

 

[tc35dforme]

Haz,

Watch the drain tie in..the gas furnace condensate is quite acidic and can tear up you drainage. They have neutralization kits that may be necessary to mellow out the condensate.

Have you considered adding a zone from your existing hot water. PEX tubing can be easy to snake up and I'd bet you have the extra capacity in the boiler plant. PEX tubing, baseboard, some controls = less than all new furnace.

Of course I'm assuming A/C isn't part of the equation.

 

[Jagmandave]

For a 450 sq ft occasional use room, why not consider one of those motel type a/c & heater combi units? All electric, you only need a drain pan, and probably it will only make water in the summer if at all. They only cost about $600 brand new.....

 

[Jagmandave]

For a 450 sq ft occasional use room, why not consider one of those motel type a/c & heater combi units? All electric, you only need a drain pan, and probably it will only make water in the summer if at all. They only cost about $600 brand new.....

 

[Sigarms]

Not sure where you can get them for $600, but most "P-tacks" (if thats what your refering to) go up to around 17k btus, hard to find one that will push 20k (not impossible), but you're looking at nothing but a heat pump or straight a/c with electric heat (could be wrong, but have never come across anything else, which means you end up probably paying more).

On "that path" Sanyo does make a split ductless mini system that can use gas for heating (you're stuck with a/c), but for the price, and depending on how much you'll use it, you'll be spending money on gas (and it only goes up to 14k on the heating side).

 

[Sigarms]

Not sure where you can get them for $600, but most "P-tacks" (if thats what your refering to) go up to around 17k btus, hard to find one that will push 20k (not impossible), but you're looking at nothing but a heat pump or straight a/c with electric heat (could be wrong, but have never come across anything else, which means you end up probably paying more).

On "that path" Sanyo does make a split ductless mini system that can use gas for heating (you're stuck with a/c), but for the price, and depending on how much you'll use it, you'll be spending money on gas (and it only goes up to 14k on the heating side).

 

[hvac1]

The least expense would be adding some baseboard heat off your existing boiler. Then put in a window unit for a/c.They almost give them away now. My heat pump will run down into the low 20's before any back up is needed. Shutting off your heat pump at 45 is not gaining you much, unless you have real cheap backup heat. In New England there isn't anything cheap. A condensing furnace with duct work isn't going to be cheap, then add in a 13 seer a/c unit. A heat pump with gas backup doesn't seem feasable for that btu requirement.

 

[hvac1]

The least expense would be adding some baseboard heat off your existing boiler. Then put in a window unit for a/c.They almost give them away now. My heat pump will run down into the low 20's before any back up is needed. Shutting off your heat pump at 45 is not gaining you much, unless you have real cheap backup heat. In New England there isn't anything cheap. A condensing furnace with duct work isn't going to be cheap, then add in a 13 seer a/c unit. A heat pump with gas backup doesn't seem feasable for that btu requirement.

 

[hazmat]

Thanks everbody for your comments.

A wall unit isn't feasable as the gable end of the house is where the big movie screen is going. The other "flat" wall is the utility room (where the units will reside).

I talked to my HVAC guy again today - he said he didn't recommend the 90% plus as they get call backs when the drain line freezes. If I insulate the attic area & the drain line, I should be fine.

To upgrade to a dual fuel unit would be $605 more. Currently I spend about $1,000 plus 4 cords of wood to heat 2,400 sq feet. I expect that the additional 400 sq feet would cost ~$200 a year to heat. I estimate that the dual fuel might save me 1/2 that =$100 -> 6 year payback on the generous side. If it only saves me $60 in fuel, then it is a 10 year payback.

If any of you are looking for business opportunities - get into the geo-thermal business. 2 quotes at $50,000 complete to install including ductwork for the whole house /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif

 

[hazmat]

Thanks everbody for your comments.

A wall unit isn't feasable as the gable end of the house is where the big movie screen is going. The other "flat" wall is the utility room (where the units will reside).

I talked to my HVAC guy again today - he said he didn't recommend the 90% plus as they get call backs when the drain line freezes. If I insulate the attic area & the drain line, I should be fine.

To upgrade to a dual fuel unit would be $605 more. Currently I spend about $1,000 plus 4 cords of wood to heat 2,400 sq feet. I expect that the additional 400 sq feet would cost ~$200 a year to heat. I estimate that the dual fuel might save me 1/2 that =$100 -> 6 year payback on the generous side. If it only saves me $60 in fuel, then it is a 10 year payback.

If any of you are looking for business opportunities - get into the geo-thermal business. 2 quotes at $50,000 complete to install including ductwork for the whole house /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif