Recommendations for Natural Gas HVAC?

[westes]

Does anyone have opinions on pros and cons of natural gas for a residential HVAC application? With natural gas costs so low during summer months, the main advantage I see to going with natural gas is that you can get very high utilization rates while still significantly saving on operating costs. With a residential electric unit, the family might have to endure a set point of 80 degrees or higher just to keep their utility bill under $500/month. With a natural gas unit, you don't have to fight peak hour summer rates on electricity and with natural gas prices lower during summer months you can probably crank down the set point on the HVAC and still have a relatively modest utility bill.

Some questions I have regarding natural gas HVAC:

1) I understand the natural gas HVAC units will be more expensive, but what are costs on comparable electric and gas units?

2) How much efficiency do you lose with natural gas?

3) I read on several sites that natural gas HVAC provides much better solutions for multiple zones within a residence. Can someone explain why this is so?

4) Since gas HVAC units often employ chillers, one question I have is whether anyone has come up with a residential unit that would store a chiller underground, so you would minimize heat loss during the heat of the day? I guess you could design such a unit to be incredibly efficient since even a few feet underground the chiller could maintain quite cool temperatures with minimum energy expended.

5) Does anyone make a gas unit that would do both heating and cooling together and would still fit into a residential application?

6) What are the recommended brands for gas HVAC?

[HVAC9900]

They were popular about 30 years ago in my neck of the woods,until air source heat pumps showed them the door.

They were fairly easy to work on, usually all that was needed was a pilot assembly, maybe some pump work.But they were expensive to buy,and most hvac companies had no clue,so owners were stuck with the installer most of the time.

Haven't done any work with them for a long time,haven't bothered to keep up on the efficiences vs heat pumps.
But here the gas rates fluctuate quite a bit while electricity is stable and cheap(relative to other areas),would be difficult to do a payback with any kind of certainty.

I would consider a water source heat pump rather than the gas fired AC,unless they have gotten a lot cheaper to buy,and had high efficiency.

[westes]

They were popular about 30 years ago in my neck of the woods,until air source heat pumps showed them the door.

They were fairly easy to work on, usually all that was needed was a pilot assembly, maybe some pump work.But they were expensive to buy,and most hvac companies had no clue,so owners were stuck with the installer most of the time.

Haven't done any work with them for a long time,haven't bothered to keep up on the efficiences vs heat pumps.
But here the gas rates fluctuate quite a bit while electricity is stable and cheap(relative to other areas),would be difficult to do a payback with any kind of certainty.

I would consider a water source heat pump rather than the gas fired AC,unless they have gotten a lot cheaper to buy,and had high efficiency.

Do you know of a good package unit that would combine an air source heat pump unit with a gas heater for use when the temperature gets too low? A SEER rating above 14 would be desirable.

Also, have you worked with geothermal heat pumps and do you have any opinion about those? I guess in theory the geothermal approach should use less energy?

[HVAC9900]

The air source with gas back up is very common, most manufacturers have them available, just depends on what brand name rings your bell, and how efficient you want to be.
The company that installs and services the equipment is often as important or more so than the equipment itself.

Yes, I really like geothermal heat pumps,with a closed loop system( piping that will take the water from outside to inside and back again without constantly adding water) they are practical,if you are going to live in the home for at least 7 years(give or take).They can be used to heat domestic water too,which can make it even more efficient.

They have no outdoor temp limitations like an air to air heat pump does.
There are several brands out there, water furnace,climate master,bard,and I used to see a lot of tetco years ago but again installer/servicer is crucial.

[westes]

The air source with gas back up is very common, most manufacturers have them available, just depends on what brand name rings your bell, and how efficient you want to be.
The company that installs and services the equipment is often as important or more so than the equipment itself.

Yes, I really like geothermal heat pumps,with a closed loop system( piping that will take the water from outside to inside and back again without constantly adding water) they are practical,if you are going to live in the home for at least 7 years(give or take).They can be used to heat domestic water too,which can make it even more efficient.

They have no outdoor temp limitations like an air to air heat pump does.
There are several brands out there, water furnace,climate master,bard,and I used to see a lot of tetco years ago but again installer/servicer is crucial.

For geothermal in particular, I really agree that you would want to find a specialty vendor who does a lot of those. Any thoughts on the best way to find a qualified contractor for the geothermal heat pumps in the San Francisco Bay Area near San Jose?

[HVAC9900]

Unfortunately not familiar with that areas contractors.One suggestion would be to go to the manufacturers sites and see who the contractors are in your area.
Then crosscheck them with one of the contractors lists-around here there are a couple, one called kudzu,the other is angie's list.All about ratings on home contractors by local people.

There may also be contractors on this site from there, but i don't recall running across any.