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Heater Replacement Question for HVAC Guys - daveferg - 11-22-2015
We're in the process of buying a new home. It was built in the late 70s and still has the original central forced air heater located in a closet in the middle of the structure, and as this is a condo, even if we could reach an outside wall (for one of the new PVC vent/intake arrangements, it likely wouldn't float with the HOA.
So, since with a 40 year old heater, it's not a matter of if, but how soon it will have to be replaced. Does anyone know if a pilotless high efficiency heater could be vented using the existing vent through the roof----also, do you really think these more expensive models actually save money?
We bought a 90% efficiency model for our current home, and while I like the pilotless ignition and the two-stage blower cycle (keeps a more even temp in the house), I never noticed a significant drop in our nat. gas usage.
Suggestions welcome. Thanks.
Re: Heater Replacement Question for HVAC Guys - blackhat - 11-22-2015
A high efficiency, PVC vented furnace can normally be vented through an existing flue if it is used as a chase for the new piping. No other appliances can discharge directly into the flue and offsets can be difficult to pass through. This could require changing the water heater to a power vented model. A 40 year old furnace is approaching the end of it's life expectancy, even with limited annual usage. Your best replacement option may be a mid efficient, perhaps a two stage, with an ECM blower.
Re: Heater Replacement Question for HVAC Guys - Robert Adams - 11-22-2015
Yes any 90% or so and higher unit with pvc pipes will work. They will vent through your existing flue. You may have to remove the steel liner and replace with pvc depending on the size.
Seen a number of instances with replacing systems using a two stage heat and even though more efficient they don't tend to reduce fuel usage. Makes the house more comfortable but doesnt make it cheaper to heat. Same with the two stage ac.
Re: Heater Replacement Question for HVAC Guys - daveferg - 11-22-2015
Thanks all. Black Hat----don't know if there are any angles in the heater, but the water heater is at least 30 ft. from the heater, so doubt they have a shared flue. (I did have that at our present location and since they went through the wall for the heater, they inserted a sleeve into the flue for the water heater.
Robert---glad you confirmed what I suspected about comfort with the two stage, but little or no fuel savings. Also, the more advanced heater tend to have way more systems----more to go wrong in the future.
Re: Heater Replacement Question for HVAC Guys - Robert Adams - 11-22-2015
Yup. More complicated more to fail. With ac stay at 16 seer and under. Those his 20 seer units are very failure prone and expensive to fix. Some units when the board fails it has to be ordered from the factory and they program it. I'm not going to be without ac for a week waiting for a replacement board. Besides when you do the numbers hose high seer units never pay for themselves in energy savings and that's not including the high cost of repairs. Also the lower seer units cool better and remove more humidity. The high seer units have a much larger coil and don't run at as low of a temp so getting moisture out is tougher.
Even the simple 80% furnaces are over complicated for what it needs to do. Never liked how long they run the draft inducer before lighting the burners. Took too long.
Re: Heater Replacement Question for HVAC Guys - Bob10 - 11-23-2015
Buy a home warranty with upgrades coverage and don't worry about it. I am looking to buy a few of them myself as it is cheaper to cover those annually than replacing appliances and HVAC out of pocket. I had my home inspector mention it to me more than once and this time I listened. Here is what he responded when I asked what company he had used for his house.
"Hi Bob,
I have Fidelity Home Warranty. There's a couple other ones out there. Their for sure the best if you have a pool. If you have older appliances or water heater you may want to get the code upgrade policy.
Randy"
Re: Heater Replacement Question for HVAC Guys - EatenByLimestone - 11-23-2015
Since this is a condo, the answer is probably no, but is there any chance that you could upgrade insulation before you move in? Depending on what's already there you may increase comfort and lower bills significantly.
Re: Heater Replacement Question for HVAC Guys - daveferg - 11-23-2015
Thanks Matt---It's on our short list. First priority is checking the heat exchanger----a red flag if leaking. We'll talk options on systems at that time. Now I know why Mom told me to save my pennies.
Having lived with one of these basic heaters in a closet inside the home, in my parent's old place there in OC, running quietly will be in the criteria list----ahead of supposed supper efficiency.
Re: Heater Replacement Question for HVAC Guys - Woodenfish - 11-23-2015
Couple of comments Dave... A condo with natural gas is almost unheard of in my area. Most every multi-family building I have ever been in is all electric. Another is that high efficiency is no longer a luxury or personal choice but a government mandate. Being so, I can not believe a condo association would have the authority to restrict direct venting. Are you sure this unit has natural gas heat? A 40 year old gas furnace is a record setter.
Re: Heater Replacement Question for HVAC Guys - Robert Adams - 11-23-2015
Not much insulation to worry about as your attached neighbors make up more of your insulation.
Loml's mom bought a condo in ohio and the only exterior walls are at the front and back.
Hers is a gas unit and really goofy type. Had no never seen that type before. Odd free standing kind of an upflow all in one unit that has a vent to the outside for condenser coils and exhaust. Brand new unit when she moved in. I'd hate to see what it would cost to heat it with electric heat though.
His venting issue with the condo is he wants to put a new thru wall exhaust instead of reusing the existing one.