HVAC question (Gas Furnace vs. Electric H. Pump) (mattress, house)

[BRH]

Hey everyone, just wondering about others opinions here in the E. Tenn. area.

After searching for a couple of years, I've finally found a home that I'm in the process of purchasing. It is an old bungalow (early 1900s), that is 1 1/2 stories. It is between 1700 and 1800 sq. ft. (about 950sq ft. downstairs and 700 to 800 upstairs). It has permastone (stamped concrete) siding that has been painted, and as far as insulation, it is so so, since it is an old home. (although I understand that the permastone siding, itself, provides some insulation benefits).

So here's my question. It currently has two HVAC units (gas furnace/ac split system downstairs and an electric heat pump with electric strips upstairs). The upstairs unit is basically brand new and in good shape, but the main unit downstairs is 15 to 20 years old and the AC compressor is shot. The seller is agreeing to pay for a new AC unit or 1/2 the cost for a whole new system (furnace & AC), which is what I want to do. What I was wondering is everyone's opinion on installing another gas split system (gas furnace in cellar and AC outside) vs. installing an electric heat pump with electric strip back ups. I'm leaning towards keeping the current gas furnace setup myself. Considering it's an old house, and will likely be kind of drafty, I'm thinking the gas heat would make more sense. Does anyone have any feelings or experiences with gas vs. electric in this type of older home? What do you think about cost difference as far as utility bills? Also, we are thinking a 1.5 ton unit for the downstairs area (around 900sq. ft.). Is that sufficient in this type of bungalow, or would I be better off with a 2 ton unit?

Thanks in advance for any help or opinions. I'm pretty excited about finally finding my house after looking for a long time, and especially excited to be buying an old bungalow (which is what I've always wanted). Thanks again.

[Pam& Bill]

Well congratulations and best of luck to you! I don't know the slightest thing about heat pumps and the like. I just wanted to wish you many years of happiness and joy in your Tn. bungalow.
Pam

[Barking Spider]

The average life of a heat pump (mostly compressor) is less than one with a gas system. This is because the a/c unit is working 12 months a year to provide heat and cooling. So you will be replacing the compressor sooner with a heat pump.
KUB will tell you that gas is more efficient and cheaper to run, and can back it up with numbers.
TVA will tell you that heat pumps are more efficient and cheaper to run, and also back it up with numbers.

Gas will provide you with a "warmer" feeling heat, since a heat pump in normal mode puts out about 90 degrees, which feels cool when it blows over your skin. It will heat the house up, but feels cool.

The best of both worlds would be a dual fuel heat pump, but they cost quite a bit more. It uses gas as the back up heat, so it is much lower cost when it is really cold outside.

If money isn't an issue, I would go with duel fuel heat pump. If it is, I would go with gas heat.

[donald cherry]

as an old 30 years gas man ,i can tell you this ,when its cold outside gas will heat faster and warmer and a gas furnace/ac can last 20/25 years good luck

[Mary_Moon]

We replaced our 30 year old propane furnace with a duel fuel heat pump/propane almost 2 years ago and even though the electricity bills are much lower in the winter than the propane bill was, I miss the full gas furnace for the way the heat felt coming out of the registers and how quickly it warmed the house up. We used to set the temp back to 54* at night (we have heated mattress pads) and the furnace could warm up the whole house to about 70* in 15-20 minutes. When I try that on the new system with its fancy-schmancy thermostat, the heat pump comes on at 1am and warms the house up in stages, taking 5 hours to reach the target. Now we just leave it at one temp all day & night which makes me feel like I'm wasting money.

Congrats on the house!

[mjb62676]

Having had both back in the plains states, I much, much, much prefer the heat pump. It makes the house COMFORTABLE.

Here, we have gas heat and then AC...the house is always either HOT or COLD...never in between. I cannot stand it and wish I could afford to rip out this 3 year old system and replace it with a heat pump. They are MUCH more efficient.

[Barking Spider]

Since a heat pump typically puts out temps of about 90 degrees, they do not lend themselves to turning down at night and back up in the morning. With a heat pump, you are better off just setting the thermostat to where you want it to be and leave it alone.

If your house is either HOT or COLD, and will not hold the temperature you want it to, there is likely something else going on. It could be a balancing issue. It could be the insulation in the attic is minimal and you are losing energy thru the roof. Same with windows, etc. No matter what energy source your HVAC system is, it should maintain the house temps for a reasonable amount of time.

[mjb62676]

Originally Posted by Barking Spider

Since a heat pump typically puts out temps of about 90 degrees, they do not lend themselves to turning down at night and back up in the morning. With a heat pump, you are better off just setting the thermostat to where you want it to be and leave it alone.

If your house is either HOT or COLD, and will not hold the temperature you want it to, there is likely something else going on. It could be a balancing issue. It could be the insulation in the attic is minimal and you are losing energy thru the roof. Same with windows, etc. No matter what energy source your HVAC system is, it should maintain the house temps for a reasonable amount of time.

We've discussed previously that I believe this is an issue of having no earth contact (crawlspace) and an insulation issue. Both builder problems...and I won't be using this builder again....ever.

On top of insulation, it seems the system for the upper level is undersized and the system for downstairs is oversized...but who knows. I know having NO vents in the kitchen really sucks.

All that being said, I'd still rather have a heat pump. I'm not a fan of gas heat at all.