Posted: 10/6/2011 12:12:36 PM EDT
|
I have an 80% LP gas furnace and conventional A/C unit that is 8 years old in a 2600 sq ft single floor house. We want to have the attic foamed in, but the installer said we need to up grade to a 90% heater since the furnace is in the attic. Question is do we stay with LP or go to a heat pump.
We are considering a heat pump instead of the gas unit, and need some advice. I am in central Texas, seldom freezing in the winter, but we do get into the 30's and a few days in the teens or 20's. We have had 90 days this year over 100, but 20 to 30 days is more the usual. We set the temp at 78 in the summer and keep it at 68 in the winter. Is a heat pump the way to go? Can you give some advice on brands or models to look for or stay away from? Any time you talk to a salesman at one of the HVAC companies, you get conflicting stories. I have had great luck getting good info here, and hope some one here can help me again. Thanks from an old Nam vet. |
|
Not sure why you need a 90+ just for insulation, don't understand that one. Anyhow you would do good with a heat pump, being in Texas and all. Heat pump is cheaper to run than a gas heater, until it drops into the twenties or so. The heat pump stops working at that point and the so called "emergency heat" kicks in, which is basically a electric toaster oven heat strip deal. Problem with that is the electric heat strips are power hogs, thus robbing you of all your energy savings. The solution would be a heat pump with a propane furnace as the second stage or "emergency heat" American standard is a good make for southern climates. |
| Go with a good electric heat pump unit I did and being the coldest natured person on the planet it took some convincing to do it. In retrospect couldnt have done anything better cut my power bill in half and I like it ok. I would light fuse and run away on LP gas it aint gonna get any cheaper. |
|
Quoted:
good Trane American standard, bad goodman rheem ruud amana Just had my 19 year old Carrier serviced today. Capacitor went out. They guy (from Sears) said I've certainly gotten more than the usual service out of it (this is Texas BTW!!). I guess it'll go soon. To the point. Is Carrier still a good buy? |
|
Foam installer is FOS, as long as you maintain the furnace manf specs on clearance, you don't need to upgrade to a 90. Dipshit probably has a company that installs furnaces or some family member or buddy is having him shill for them.
Your biggest issue will be make up combustion air for the burners and that is something that can be factored in with a fresh air intake of sufficient size. |
|
Quoted:
I have an 80% LP gas furnace and conventional A/C unit that is 8 years old in a 2600 sq ft single floor house. We want to have the attic foamed in, but the installer said we need to up grade to a 90% heater since the furnace is in the attic. Question is do we stay with LP or go to a heat pump. We are considering a heat pump instead of the gas unit, and need some advice. I am in central Texas, seldom freezing in the winter, but we do get into the 30's and a few days in the teens or 20's. We have had 90 days this year over 100, but 20 to 30 days is more the usual. We set the temp at 78 in the summer and keep it at 68 in the winter. Is a heat pump the way to go? Can you give some advice on brands or models to look for or stay away from? Any time you talk to a salesman at one of the HVAC companies, you get conflicting stories. I have had great luck getting good info here, and hope some one here can help me again. Thanks from an old Nam vet. Who is the installer? Is this guy the one who wants to replace your unit, or is he recommending someone? If so, I would get a quote from a couple of other businesses in the area. We just had our furnace and swamp cooler replaced last year and went with refrigerated air. First, second and fourth companies all quoted outrageous shit, including telling us that the circuit breaker box had to be replaced. Third company gave great quote and told me about the circuit breaker box scam. Guess who got the job?! |
|
Quoted:
Foam installer is FOS, as long as you maintain the furnace manf specs on clearance, you don't need to upgrade to a 90. Dipshit probably has a company that installs furnaces or some family member or buddy is having him shill for them. Your biggest issue will be make up combustion air for the burners and that is something that can be factored in with a fresh air intake of sufficient size. Big +1 on this, as long as clearance is maintained and intake air is not restricted your working furnace will be fine. |
|
Build a room around the furnace, insulate all around that. What sure you have enough combustion air (outside air) coming in to that room. If you've been doing good maintenance on the system it should last quite a while longer. Heat pumps are much more maintenance queens, that compressor will run almost all year (granted it will cycle when not needed), and that's a lot of wear and tear. Much more ware and tear than a AC only system. I'd leave the furnace in place and add the heat pump if you want. But again, if you've got no problems with it, it should still last 5 or more years no problem.
Set the furnace to run when it's 40 or below, and the heat pump above that. That way you still have the furnace to provide heat. You can run a furnace off a generator much easier than a heat pump / with electric backup heat. If LP prices go up you can run the HP dow lower, but below 34-36 degrees it's almost always running on back up strip heat not the HP compressor. If electricity rates go up, you can up the temp you change over and run more LP. Options. One thing to remember is that a heat pump will at best have about 90-95 degree leaving air temps, so using setbacks at night is bad, at least over 3-4 degrees., A HP takes a lot longer to warm up a house, if you jerk the thermostat up and down a lot at night and in the morning you'll just make the electric strip heat come on and your savings are gone. Furnaces LP or gas it's more like 120+ Heat pumps need more ductwork, since they need to move a lot more air for a given heat output. Not all systems designed for gas / lp and AC are large enough for heat pumps and you'll need to upsize the ductwork a little. If it's restricted you'll put a lot more ware and tear on the compressor and it's like to have a short life. HP save electricity, but require more maintenance. That doesn't always add up to savings in the end. In the summer a HP is just an AC, the only savings you'll get there is from a newer higher EER / SEER unit. If you don't heat that much and it's mostly cooling, it will take a lot longer to pay for a new HP system. |
|
Quoted:
I have an 80% LP gas furnace and conventional A/C unit that is 8 years old in a 2600 sq ft single floor house. We want to have the attic foamed in, but the installer said we need to up grade to a 90% heater since the furnace is in the attic. Question is do we stay with LP or go to a heat pump. we are considering a heat pump instead of the gas unit, and need some advice. I am in central Texas, seldom freezing in the winter, but we do get into the 30's and a few days in the teens or 20's. We have had 90 days this year over 100, but 20 to 30 days is more the usual. We set the temp at 78 in the summer and keep it at 68 in the winter. Is a heat pump the way to go? Can you give some advice on brands or models to look for or stay away from? Any time you talk to a salesman at one of the HVAC companies, you get conflicting stories. I have had great luck getting good info here, and hope some one here can help me again. Thanks from an old Nam vet. ETA foam installed is sealing the attic so as to prevent infiltration of outside air..ie no combustion air for 80% furnace if you foam the attic you will need to convert the gas furnace to a 90%+ unit This will need to be ran as a 2 pipe setup (1 combustion air & 1 exhaust pipe) The Carrier GreenSpeed heat pump will give you rated capacity down to 6-7 degrees...a standard heat pump starts to lose capacity around 47 degrees. It ain't cheap in initial cost but will give impressive comfort and save you $ each month . I have a friend who beta tested one of the systems. His testimony is causing me to install one this fall |