central air or heat pump

I currently have a central air condition / gas furnace combination unit tha t is 15 years old. The a coil for the AC has major leaks and cannot be repa ired. Should I replace just the A coil and still have a 15 year old un it,put in new central A C, or put in a heat pump? The winter temps here ar e in the teens but I would have gas backup. How does a heat pump work? an y reply will be appreciated!!!! Herb
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Friday, July 25, 2014 1:18:41 PM UTC-4, herb white wrote:

paired. Should I replace just the A coil and still have a 15 year old unit,put in new central A C, or put in a heat pump? The winter temps here are in the teens but I would have gas backup. How does a heat pump work? any reply will be appreciated!!!! Herb
A heat pump is very similar to the AC you already have, except that it can be reversed, An AC is a heat pump too, it's just that it only pumps in one direction. Heat gets pumped from the house outside. You have two coils, one inside, one outside that serve as heat exchangers. To get heat, the pump just works in the opposite direction.
If your winter temps get into the teens and you have nat gas available, it's likely you can't beat the cost/performance of nat gas heat. Nat gas is plentiful and usually the cheapest energy source. You can probably find some energy calculators online that let you put in the cost of nat gas, electric, etc and give you an idea. The other factor with a heat pump is that when it's cold, the recovery time is going to be long and if you want heat fast, you're going to have to go to gas or electric backup.
I guess it comes down to factors that we don't know. How much to just replace the AC coils? Eff of old unit? Used a lot or a litte? Cost of elec? Eff of existing furnace? If it were me, I'd probably be looking at either fixing the existing one or a whole new gas furnace/AC. You say you'd have nat gas furnace as backup, which I guess implies that you'd be looking at a whole new dual fuel system, nat gas and heat pump? Doesn't make sense to me when nat gas is cheap, unless you have some unusua lly low elec rates.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 7/25/2014 1:18 PM, herb white wrote:

a coil for the AC has major leaks and cannot be repaired. Should I replace just the A coil and still have a 15 year old unit,put in new central A C, or put in a heat pump? The winter temps here are in the teens but I would have gas backup. How does a heat pump work? any reply will be appreciated!!!! Herb

We don't really have enough information. 15 year old system is likely R-22. With what you wrote, I'd be tempted to replace the A coil, and have the outdoor unit professionally cleaned. You'll get several more replies, and each will go in a different direction.
--
.
Christopher A. Young
Learn about Jesus
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I would go with the heat pump and gas backup. Put in a whole new heat pump system so everything will work together. When the air temperature gets around 25 deg or so the heat pump will loose efficency and that would be the time to switch over to the gas heat. Idoubt the cost of a HP would be much more than a simple AC.
A heat pump is nothing more than an aircondition system that is made to be reversed. Just think of it like a window AC that you turn around when you want heat. This is done by valves that change the direction of the refrigerant flow, in simple terms.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Friday, July 25, 2014 3:34:15 PM UTC-4, Ralph Mowery wrote:

That would be a new hybrid heat pump/nat gas system, which isn't going to be cheap. I don't see the need or the payback. Nat gas is cheap and you can get 93%+ efficiency for not a lot of money. IDK where it's in the teens in the winter and it's competitve to use a heat pump instead of just burning the natural gas for heat.
When the air temperature gets

And before that it doesn't cost much at all to heat the house with nat gas. I'd like to see him run a calculator and get back to us on the results. Unless he has some super low electric rates, I don't see the advantage to the heat pump. I do see a lot of drawbacks. He should also take a look around and see what other folks are using in his area. Here in NJ, it gets down into the teens in winter. IDK of a single home that uses an air source heat pump. Not one. I do know of a couple of folks that put in geothermal heat pumps, but the cost of that is maybe 3 or 4X and it will never pay for the up front cost delta. Some of that was paid for by the sucker taxpayers, but even so, it will never pay back. It's in the realm of the feel good tree hugging hippies.

I bet it is more, because it has to be sized bigger to generate enough heat. And what he really needs if he goes that route is a whole hybrid system and the cost of that is certainly going to be substantially more than a gas furnace and AC.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 7/25/2014 1:18 PM, herb white wrote:

Without knowing the numbers it is not possible to say for sure. Replacing the coil is a crap shoot. You could get 10 more years, you could get 10 more days before the compressor goes.
Just like a 15 year old car with a bad transmillion. Where do you stop pouring money into repairs?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

with 450000+km on it. The exhaust was noisy too. Wasn't sure what to do. He had me test drive it - he thought the engine was cutting out (and he was getting a random missfire code). I figured it was transmission trouble (he had just had the fluid "flushed" at a lube shop about 2 months ago, and it was over-full). I sent him to my transmission guy who verified the throttle valve was hanging up because of a rusted cable -he freed up the cable and did a proper drain/flush of the transmission with the proper fluid and BG conditioner - $300 total cost. Then he still had a bit of a strange shift - found the TPS was flakey. After the TPS was replaced it shifted like brand new. Virtually no metal or brake material in the pan or filter. He had the exhaust replaced and a front wheel bearing - total cost, including Transmission- $1500 including taxes.
He took it home and replaced the spark plugs and rocker gasket - figures it should be good for another 100,000km.
If the trans needed expensive repairs, it would have been time to bail - and at most transmission shops it WOULD have been an expensive transmission repair. They would have looked at the odometer and said "rebuild".
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
herb white posted for all of us...
And I know how to SNIP

Times has this subject been asked and answered with the same results?
--
Tekkie

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.