“It is an atypical system that pulls water out of a steel well in a room off of our basement into a pressurized tank that then feeds two chillers, one each for the first and second floors. The chillers use the ground water as a booster with refrigerant to cool the air which is then fed by ducts to each room. There is a single large return under our foyer stairs that feeds back to both units. The system failure appears to have occurred at the well pump. We have determined that parts may not be available for repair and we have not found anyone willing to work on a 95 year old steel well inside of a house.”

The fact that you seem to have access to a water well might mean that you can install a geothermal ground source heat pump system without having to drill any new boreholes is something that you should explore with a geothermal designer/installer before committing to any other heat pump or gas furnace option.

What additional details can you provide regarding this water well?

IMPO

SR

If the failure of the existing air conditioning system is due to a problem with the pump and the rest of the air conditioning and heating systems are otherwise sound, I would definitely investigate repairing or replacing the pump vs. changing out the system before committing to a completely new system.

when we bought the house our initial plan was to eventually to replace the chillers with more efficient units retaining the rest of the system but I was concerned with both the longevity of the welland the tank and the potential difficulty working witheither of these components if anything happened to them. For reference here are the top of the well, pump controller and tank:

We haven’t specificallt talked to a geothermal company. but I’m not sure that it would easily covert to a vertical loop? We also talked to five different well companies and while none came to the house, some did a virtual consultation. None wanted to go any further when they learned it was a steel well and warned we were likely looking at a 10k repair.

The air conditioning system being sound is technically true but we might have already been pushing their usefull life. They tun on R22 and both leak refrigerant. We spent $700 to refill them this year and with rising prices could spend more next year. They are also at an age where if a component fails there may not be replacement parts. Its maybe not the environmentally responsible choice to keep them around. we were essentially constantly pumping water out of tge gro7nd then dumping it into tge sewer. Here are the chillers for reference:

I am very much a proponent of repair rather than replace. But all of the signs are all pointing against it here. i also think geothermal would be fantastic but im under orders from my SO to get this done soon so its no longer 83 inside and I suspect the geothermal will break the bank at a time when money is tight.

I don't know what parameters you gave to the three HVAC companies, but you've been presented with three very different, okay, I'll say it-- apples and oranges- options for replacement of your home's HVAC system.

If you want to make an informed choice between the three companies, you need to get everyone on the same page--or at least starting on the same page. You do that by providing standard specifications for bidding purposes. If you prefer a more open-ended approach, you can ask the companies to provide options in different budget ranges. For example, you might ask for options in the $10K to $15K range, $15K to $20K range, and $20K to $25K range.

Your local gas and electric companies may offer some technical recommendations as to what options work best in your climate. They may offer credits to help with the cost of an energy-efficient replacement system. There are some federal tax credits which you may be able to qualify for, too. https://www.energystar.gov/about/federal_tax_credits

For what it's worth, I lived in your climate zone for a number of years in a home with a heat pump and electric strip heaters for backup heating. While I wouldn't recommend the strip heater option for backup heating, you might consider a hybrid system consisting of a heat pump with a gas furnace for backup heat. That way you're not firing up the furnace to take the chill off the house when the outdoor temperature is in the 50's and 60's and the heat pump can more economically deliver the required heating, and you've got the gas furnace option for times when Chicago competes for the coldest place on earth award.

It should be easy enough to test your well to see if it can support a GSHP system. If it can and you live in the US, you’ll get a 26% credit off the cost on your Federal taxes.

The first thing I would suggest for your situation would be a complete, comprehensive and independent evaluation of the heat loss/heat gain of your envelope. This would include a Manual J and a Manual D evaluation of the duct system as well. You will then have to consider energy cost of not just today but going forward as well, electricity verses gas.

Based on the information you provided, your home will always be expensive to space condition. You will have to decide whether you want to pay up front for a system that in addition to providing comfort will be cheaper to install or cheaper to operate.

You will have to project where energy cost is headed and life cycle costs as well; some equipment might last twice as long as others so replacement cost might also be a factor.

Can you provide info on annual energy costs and unit cost of kW & Therm?

Another solution that I’m not recommending but what others might do would be to install an inexpensive central system and make up for zone deficiencies with mini split heat pumps.

IMPO

SR

OK, something's not right (REALLY not right) with the 3 quotes you got. Either #1 is ripping you off and #2 and #3 are on the right track, or: #1 knows something about your installation that numbers 2 and 3 don't.

Regardless, the equipment cost of #1 (non-modulating) is well under $10,000 so you need to ask them what labor they are providing for $14,000 ("cleaning the whole system, balancing existing dampers, changing out inappropriate registers, and a 2 year maintenance contract" isn't even close)!

Charles Ross,

Thank you for the input. Understood what you have said regarding leveling the field and creating comparables. Not knowing enough about the different systems available and what would work best we have kept it open, plus we have learned that some of the local contractors have a set of brands that they supply and will work with. For instance contractor 1, who we have worked with on the maintenance of this house so far is only offering Carrier units, and has said that he can't get his prices below $20,000 for any system. On that alone he is probably out of the running, but then contractor 3 priced out the same Carrier Infinity system as contractor 1, but with two units instead of 3, and his price is coming in $10k lower than Contractor 1 with a single unit (though part of that $10k is the maintenance plan, balancing, and duct cleaning that was offered by Contractor 1.

We also got some clarification on the units that Contractor 3 is proposing. His $11,000 price was for two Ameristar 13 SEER 4 ton M4AC3 condenser with a Tempstar EAD4X evaporator coil, and Ameristar 120,000 BTU M952V furnace with 96 AFUE and 5 ton blower. Overall the main pro with this proposal one seems to be getting 2 systems for a good price. But we have the following concerns or questions that we want to discuss with the contractor:

• 13 SEER seems awful low for our climate. It seems like it would be worthwhile to upgrade to 16 SEER. But will we notice a measurable difference with the more expensive 26 SEER Carrier system?
• The 16 SEER system is also supposedly much quieter than the 13 SEER (76 rather than 67 dB) which when there are two outside our kitchen window I think would make a difference.
• I do like the idea of the heat pump instead of a furnace to avoid running more gas and another exhaust pipe across the basement especially since this furnace is offering backup heat to our existing gas boiler.
• Is there any disadvantage to having a oversized furnace if it isn't used at full winter capacity?
• Probably our biggest question: is two 4 ton condensers and 5 ton blowers oversized four our house? (more on that in my response below).

I am going to agree with some of the comments posted so far. The contractors so far are guessing on the equipment size. You need a proper load calculation. I am of the opinion that the contractor should do his own load calculations. But they all refuse or incapable then hire a third party.

The Carrier equipment in quote #1 is very nice. However the quotes for the two configurations are about 2X as to what they should be. I realize prices have gone up during COVID-19 but these prices seem excessive. The only possible explanation is the job is the the typical equipment replacement and requires much more in labor and materials.

Quote #2 would be reasonable if you had no natural gas service. Quote #3 is very over sized and the price is suspiciously low for what is being proposed.

fsq4cw, thanks for the additional thoughts.

Here is what we current spend and use for energy:

gas usage (heating, water heater, clothes drier):

• total used for 2020: 2779 therms
• average usage 2020: 232 therms per month
• highest usage: 590 therms in February
• Current gas charge: $0.21 per therm

electric usage (AC, well, mostly LED lights, there is some spike in winter for our mostly incandescent outdoor Christmas lights for 2 months, and some of this is our 72" 35 year old sub zero refrigerator/freezer):

• total used for 2020: 9430 kWh
• average usage 2020: 786 kWh per month
• highest usage: 1394 kWh in September
• Current electric charge: $12.4 per kWh

Total cost of electric and gas in 2020: $3360 or $280 per month

Our house is set at 66 during the day in the winter and 63 at night. Ideally it would be 68 day 66 night, but that is part of our cost savings. In summer it is set 78 during the day and 75 at night. The current system is incapable of cooling below 74 in the middle of summer.

I also did some modeling and analysis of my own last night. I modelled the house in BEopt and also tried using CoolCalc. In BEopt I got as accurate as I could with window size and orientation, wall and roof materials, attic insulation, and used a closed cell 8" CMU with brick face and 2 layers of gyp. bd. to approximate our exterior brick wall construction. BEopt modeled a max cooling load of 60k BTU and max heating load of 340k (!) BTU. Coolcalc definitely didn't have as many input variables, and assuming a 76 degree cooling indoor setpoint and 66 degree heating came up with 40k BTUH cooling and 148k BTUH heating.

These both seem to suggest that the 8 ton of units proposed by contractor 3 may be too much. But I don't have a good understanding of how they would function on days when we are really only cooling one floor or the other at a time. Also based on what I have read I am concerned that our ductwork isn't sized for a pair of 5 ton blowers either. Can a combined 420 square inch return duct and (2) 288 square inch supply ducts even accommodate 10 tons total?

Re: OP

“Is there any disadvantage to having a oversized furnace if it isn't used at full winter capacity?”

If installing an all-electric Carrier Infinity GreenSpeed system, I would round up to the next full ton size.

“But will we notice a measurable difference with the more expensive 26 SEER Carrier system?”

Again, a fully variable GreenSpeed system by being able to ramp up and down will be better able to handle load conditions both in heating and air-conditioning where variable speed will provide better dehumidification. Fully variable will also provide better flexibility if zoning is involved to deliver the proper constant volumes of air flow where and when required. The Infinity fan coil is also capable of analyzing and self adjusting to the ductwork it’s connected to - within limits. There is less of a likelihood of a serious sizing error with GreenSpeed as long as it’s not under sized. Over sizing will cost more money but allow for future expansion if renovating without compromising comfort. The GreenSpeed heat pump also uses Electronic Expansion Valve (EXV) in heating mode for better control and efficiency.

I would say that for 100-year old homes that are not renovated to today’s standards that the best way to bring HVAC operating costs low is with Geothermal. One system for heating, air-conditioning and most of your DHW. One system with nothing visible outdoors, no back yard noise, nothing exposed to the elements and a system that will likely last twice as long as anything else you will install today that will also provides air-conditioning. Also without any energy wasting defrost modes as that’s not required. The cost differential is mainly in the drilling and installation of a ground loop.

You might have to upgrade your electrical entrance and panel regardless of what you install.

IMPO

SR

Homes which benefit the most from high-efficiency HVAC systems are ones that are leaky and have little or no insulation, like the OP's. As the shell performs better, the value of higher-efficiency HVAC systems becomes subject to the law of diminishing return.

You simply can't compare a Carrier Infinity system installed with a zone control system--which is on the high end with respect both initial cost and performance-- with anything that has an "Ameristar" label on it (it's American Standard's low-end product.) I also don't see how they are going to furnish and install two systems for $11K; I suspect they've left something out of their estimate or there's a surprise waiting for you in the fine print of their proposal.

In general, you get what you pay for. I suggest you consider the annual cost of ownership of each of the systems assuming a life expectancy of 15 years +/- Then figure in the additional comfort level associated with zone-controls and variable speed equipment.

Sorry to rain on your parade A Fox but you're looking at a few more problems than just picking a HVAC system, but minor to the tune of around $4,000. Seems if you stop using that well the state of Illinois requires you to have the well sealed by a licensed water well driller within 30 days after it's abandoned and no longer used.

Around my neck of the woods (Minnesota) it runs between $3K and $5K. I know the price range because I had a well sealed in my mother,s home last summer and took bids from 3 drillers. You may be able to avoid sealing the well if you replace the pump and use it to water the grass.

Their are advantages to having your own watering well, like allowing you to sprinkle any time of the day or night because it's your own well and the city can't force you to follow their watering time frames. You also won't need to pay the city for the water you use to water the lawn or wash the car and avoid sewer charges based on water usage from watering the lawn. You could also have the water tested and may find it's much cleaner than city water and hook it back up to the house. I believe it was the original water source for the house to begin with because it's kind of hard to drill a well in a basement with a house above. The well could be an asset and save you a bundle on water bills or could be abandoned and cost you a small bundle, your choice.

I do know in many municipalities it is Illegal to have a pump and dump geo system like yours and once a contractor starts pulling mechanical permits with city inspectors poking around you may have problems dealing with the city and not the Illinois department of health who would oversee the sealing. Give them a call and find out, 217-782-5830. If you go to sell the house the well will need to be disclosed and will need to be sealed so you may as well decide now. One cheap remedy would hook a hand pump up to the pipe and claim it's still in use and have a emergency water source in case of a power failure from an EMP. I personally think it's something to keep.

I also read your electric company has an incentive program for geothermal systems. If the well is deep enough and it's a 4" casing you could slip one closed loop down the well and supplement a new system like someone did 60 years ago with the well, and this is the only reason it's not sealed now. The major cost in a geothermal is the drilling and you have one well which could be used for something, even dehumidifying the basement so Get creative, call you power company and see what they have to say, get all your option.

kevin9408 post is certainly an eye-opener & a heads up but perhaps an opportunity too.

I would never recommend a ‘pump & dump’ system particularly in the city. However something might be possible in your situation. You might be able to install an open loop Geothermal system that would consist of just 1-new well as a source and use your existing well as a responsible water return to the same aquifer if a new well can be drilled a minimum of 80ft away.

The benefits are you would not (hopefully) require any drilling in the basement of your home if your existing well can dissipate (sink) at least 12.5 gallons per minute, minimum for a nominal 5-ton system. The new well can be drilled to a depth that would ensure an adequate water supply under all ‘normal’ conditions.

The down side is that the efficiency of the system would be dependant on the depth of the new supply well. That affects drilling cost but even more importantly pumping costs if the well is too deep as an open loop system is not a balanced system as is a closed loop system. You would have to consider the cost of ‘lifting’ the water out of the well. Think of an elevator system without the counter weights that would necessitate a more powerful motor costing more to operate.

The up side is that you could have the most efficient Geothermal system possible with a COP of up to 5 that would mean there would likely be nothing else that could come even close, unless your electric utility has a special rate structure for hybrid gas-electric systems in which case you can benefit even more, especially since geothermal systems are not impacted directly by ambient air temperature change, have no defrost modes and better systems use fully variable compressors with Electronic Expansion Valves and variable speed ECM blowers.

Even greater efficiency and zoning comfort can be had with an hydronic distribution system but that’s another whole other subject.

Charles Ross Homes is completely right and accurate in mentioning older leaky homes benefiting most from higher efficiency systems. I alluded to that in my previous post but Charles Ross fully articulated it.

IMPO

SR

• Current gas charge: $0.21 per therm

Your price for natural gas does not seem right. The current spot price at the Henry Hub in Louisiana is currently twice that amount. Check your bill for the service and delivery charges.

• Current electric charge: $12.4 per kWh

Is the rate supposed to be $0.124 per kWh? Is it is then that is a good rate if it includes service and delivery charges.

Have you considered getting a good HVAC engineer to review your situation? Maybe not to spec everything out, but to give you guidance on approach and sizes of equipment.

Thanks for all the continuing thoughts. A quick clarification for anyone looking into the specifics, we are actually located in Hammond, IN, 2 miles outside of Chicago. I used Chicago area for anyone that didn't know where that was, but that also puts us under different regulations and in a different utility territory (Nipsco for gas and electric).

kevin9408, Thank you for the thoughts on well sealing. Indiana requires this to be done within 1 year with a welded steel plate. The intent here is to keep runoff, animal manure, fertilizer, etc from getting into the ground water source, which should not be an issue since the well is in our basement. It also currently has a bolted steel lid. Since I suspect the city doesn't even know the well exists, I am tending toward not going anywhere down that road until forced.

mike_home, correct I meant $0.124 per kWh +$13.50 per month. You are correct that I was missing some extra charges for gas. Actual rate is about $0.74 per therm for July.

You have a big heating bill considering you set your thermostat at 66 degrees during the day and 63 at night. Most people set their thermostats at 70 - 72 degrees in the winter.

Some answers to your questions:

• 13 SEER seems awful low for our climate. It seems like it would be worthwhile to upgrade to 16 SEER. But will we notice a measurable difference with the more expensive 26 SEER Carrier system?

Most 13 SEER equipment tends to be entry level. At 16 SEER you often get better built equipment at a good value. I don't think a 26 SEER AC is worth it in your climate.

• The 16 SEER system is also supposedly much quieter than the 13 SEER (76 rather than 67 dB) which when there are two outside our kitchen window I think would make a difference.

Manufacturers will post amount of noise in the product data sheet. The better equipment tends to be quieter.

• I do like the idea of the heat pump instead of a furnace to avoid running more gas and another exhaust pipe across the basement especially since this furnace is offering backup heat to our existing gas boiler.

Are you planning to keep your existing steam boiler? Steam heat is nice but inefficient. If you are looking to lower your heating costs then you should reconsider.

• Is there any disadvantage to having a oversized furnace if it isn't used at full winter capacity?

An oversized furnace will run in short cycles which is inefficient. It is also more wear and tear on the equipment.

• Probably our biggest question: is two 4 ton condensers and 5 ton blowers oversized four our house? (more on that in my response below).

Probably oversized, but a heating and cooling calculation is the best way to determine this.

Another thing to consider in this project -

It's not clear one way or the other from the photos but older houses often have asbestos materials covering parts of HVAC equipment, whether ducts, plenums, vent pipes, etc. You may want to ask for an assessment of that and if present, what should be done.

First some background information:

Our house was built in 1925 in the Chicago area. It is 3100 sf net interior are above ground (1800 sf first floor, 1300 sf second) with an 1800 sf unfinished basement. Its exterior walls are of plaster directly over 3 wythe (layer) solid brick construction. There is no wall insulation, nor will there ever be, but we have decent thermal mass.

So this is probably why you're getting the quotes you're getting. 8 tons of cooling is a lot for that square footage... but no insulation factor or very little. Heat loads are primarily "guessed at" with homes this old.

To say you need a heat load. Yes, but with GIGO how are you going to know it's right? Typical buildings have insulation with R value to determine the multiplier to construct the heat load. (GIGO stands for garbage in, garbage out.)

Thermal mass is still quite low R-value when it comes to calculating a heat load. Typical R-values for walls usually any where from R-11 up to R-19, maybe even higher in building methods today.

Concrete, brick walls etc. will not achieve any where near even R-11. So for that reason it kind of makes energy efficiency a moot point with a structure of this nature.

The other things against you is that Chicago is a low use climate for air conditioning. Typically 3 months cooling season there. I lived there just over 20 years ago. --- you should be more focused spending the money on a better heating system IMO.

But a house like this in -40F below zero windchills yeah that's probably going to cost you in a house like this. It is what it is, no real way around that, except to bull doze and build new.

With better insulating factors I would put it at around 2.5-3 ton for the lower level, 2 ton for the upper level. 13 SEER AC for your climate is appropriate. Anything higher than that and you're just not going to recoup the extra cost of the higher SEER AC equipment. The run time it runs at $0.12 per kwh you'll likely never recoup the cost.

The furnace is a different story. It would probably pay you to put in a modulating gas furnace for your climate and build conditions. (old house with brick walls, no insulation etc)

A heat pump would be out of the equation for this house, IMO. Gas heat has it's uses.

Heat pumps work by pulling heat from outside air and pumping it indoors. The colder it is outside, the more heat is needed inside. The less insulating factor the more heat you need. Vicious circle. Gas heat doesn't have rules like this. As long as the gas / electricity flows you got heat...

If you decide on Geo --- that is a completely different discussion -- it "may" be the better choice for you depending on things mentioned by others already.

I service the Katy, Texas area.

Concrete, brick walls etc. will not achieve any where near even R-11. So for that reason it kind of makes energy efficiency a moot point with a structure of this nature.

I agree that masonry construction generally produces low R-values (autoclaved aerated concrete and ICFs being notable exceptions.) However, the assertion that energy efficiency is moot in homes like the OP's is simply wrong. To restate a portion of my earlier post:

Homes which benefit the most from high-efficiency HVAC systems are ones that are leaky and have little or no insulation, like the OP's. As the shell performs better, the value of higher-efficiency HVAC systems becomes subject to the law of diminishing return.

The OP has indicated there isn't an option to add insulation to improve the performance of the walls, they can't replace the windows with insulated glass, and they've already added insulation in the attic. Given this limitation, the efficiency of HVAC equipment becomes more--not less--important because they'll be using a lot of energy relative to a home with a high-performing shell. Do you think the OP's energy bills in a poorly-insulated structure will be lower with an 80% AFUE furnace or a 92% AFUE furnace?

Charles Ross, it's pointless to argue with a builder on a "pre-existing" home. Is new home building really this slow in Virginia that you waste your time here?

You're a builder of new homes? Are you not?

In terms of heating efficiency: Clearly you didn't read my post thoroughly. No where does my post say anything about 80% for Chicago area.... Re-read it.

Everything is an argument with you... why?

Elmer J Fudd,

Thanks for the thought. We are very much aware of the asbestos within our basement, which is largely limited to pipe wrap on the ground water pipes and boiler steam lines. It is all still in good condition, and we have been checking and rechecking that the work that is currently proposed will not disturb any of them. And we can always go back and abate and remove at a later period if it makes sense.

If I was stuck between south Chicago and Gary I'd spend the money on bullet proof windows or move. From the population loss from 2010 to 2020 it looks like a lot of people are moving out so don't go overboard on the A/C and go with the cheapest. And the idea you need 8 tons of cooling is ridiculous, 4 to 5 max even in your old house.

I can cool my 500 sq. ft. workshop without insulation when it's 98 degrees outside with only a 5000 Btu window unit to 69 degrees and that's a fact.

Some additional updates from the last few days:

We are fairly certain that our current units are 3.5 ton units. I also measured out the duct work and confirmed that both units begin with 288 square inches of duct and retain roughly that overall sectional area as it splits into each of the individual offshoots and registers. Although the combined return is a little smaller at 420 square inches total, it seems like the system was very intentional and calculated in it's design.

We have brought out contractor 3 again (the low price). I wasn't home the last time he was there, and the things that struck me is that he is definitely of the old-school contractor type, I don't believe he has done any calculations, and he is basing his equipment largely upon experience. Knowing now that our attic is insulated, he dropped the downstairs condenser unit to 3 ton (so now 7 ton total) but is holding firm to the combined 10 tons of blower and 240,000 BTU of furnace. His explanation there is that the 24" dimension of the furnace units was needed to coordinate with the Tempstar evaporator coil that sits on top of it and that the variable speed blower and two stage furnace would be able to adjust for the actual heating and air needs. We did also upgrade to the 16 SEER condensers.

Beyond that though, his only backup has been to trust him and he knows what our house needs. That and the pushy messages today that he is ready to buy and if we wait any longer we may miss out on available stock has been a little off-putting.

Following the second walk with contractor 3, we went back to contractor 2 asking for a cost effective alternate using two separate units. They returned with two single stage 45k BTU Armstrong furnaces with two 3 ton 16 SEER condensers. Based on what he was walking through, he has modeled the house, using a program that inputs overall envelope, wall R value, and attic R value (and I assume other variables). His attic insulation at R25 was probably conservative and it was still showing that 5 tons was adequate.

Ah, so you have multiple systems - that wasn't apparent in your original post. Two 3 ton AC units should be sufficient for your home if two zones are enough. If you need 3 different areas cooled then you're probably looking at a combined 6 tons of cooling (eg 3 x 2 ton systems or 2 x 1.5 ton, 1x3 ton). This assumes your cooling requirements are higher than typical because of the construction of your home (ordinarily 6 ton's would be considered a bit much).

I wouldn't use any contractor who doesn't do a detailed load calculation to size the equipment. Period. They're easy to fake, working backwards from the desired result to plug inputs in to get there.

You have enough unique things going on with your home that guessing or use the same as what's there is unlikely to give you the results you want. You don't want oversized anything, most especially not oversized AC equipment. I would also stick with gas furnaces, you can get high efficiencies from them (forget the cosmetics of new piping, if needed) and save money in your cold winter area.

Don't let anyone talk you out of keeping separate systems for separate floors, that's a big plus.

Good luck.

Ray,

When houzzers read advice from trade "professionals" they should be getting professional caliber advice. Your statement: "Concrete, brick walls etc. will not achieve any where near even R-11. So for that reason it kind of makes energy efficiency a moot point with a structure of this nature." is simply wrong advice. Purchasing energy-efficient HVAC systems has the greatest potential return in leaky, poorly-insulated structures such as the OP's home. That holds true whether its for heating or cooling. It's anything but moot, Ray.

The OP will need to trade off the higher initial cost against the lower operating cost when considering higher efficiency units and make the choice that best suits their needs. It's unfortunate that none of the HVAC contractors they're working with have been able to help in that regard. In my experience, there's a world of difference between HVAC contractors who do new, high-end construction and replacement contractors who simply swap out equipment.

Judging from annual climate data for the Chicago area, the OP would be well served to consider a hybrid system consisting of a heat pump coupled with a gas furnace for back up. It looks like the heat pump would meet the heating needs during the months of April, May, October and November and they'll have the gas furnace for heating when it's too cold for the heat pump to do the job. I had a hybrid system in my former home and it saved money versus an air conditioner and furnace.

The original author stated:

mike_home, correct I meant $0.124 per kWh +$13.50 per month. You are correct that I was missing some extra charges for gas. Actual rate is about $0.74 per therm for July.

Using these energy costs the cost to product 100K BTUs of heat are:

Electric heat: $3.63

Heat pump at COP of 3.0: $1.21

Heat pump at COP of 2.5: $1.45

Gas furnace at AFUE at 95%: $0.78

At these prices the gas furnace would be the lowest cost to operate. If you would need of COP of 5.0 in order to reach the gas furnace cost. This might be achievable with a geothermal type system.

I don't see the benefit of a dual fuel (hybrid) system. It would cost more to install and the create additional wear and team on the heat pump when operating during the heating months.

@mike_home,

Math when it's Miller time makes my head hurt, but it doesn't cost $36.34 in electric cost to generate the equivalent of 100,000 BTUs. You're off by an order of magnitude. 1 BTU = .00029371 kwh The cost would be closer to $3.64 (ignoring the effect of the fixed monthly charge which is trivial.) Have a go at the other calculations.

Charles,

You are correct! I posted the number for 1 million BTUs. This is what happens when you try to multitask. Thanks for pointing out my error. I edited my previous post with the corrected numbers.

The hybrid gives the option of either gas or heat pump heat for a modest incremental cost over the cost of an air conditioner and furnace combo. I don't have a crystal ball, but with all the talk about a carbon tax, a 15 year +/- system life expectancy, and the flexibility of two alternative fuel sources, it might be worth the incremental investment as a risk management strategy.

Gas is billed in therms, 100K BTUs (of input) so electrical resistance heat is more than 3X more expensive to produce heat than is gas. So is heat from a heat pump, given those gas prices.

For those with an environmental bent, home gas furnaces are more efficient at producing useable energy from burning gas than are electric plants that produce power from natural gas turbines. I've read they're something less than 70% efficient in converting gas to electrical energy, when considering the net energy delivered to a home, even with the newest technologies and equipment.

In my experience, there's a world of difference between HVAC contractors who do new, high-end construction and replacement contractors who simply swap out equipment.

Mr. Ross "your" experience.... vs my experience... people call me to fix it after you (IE any builder) are long gone. In most cases this amounts to as little as 1 year after the structure is built.

Sometimes it's as simple as an equipment changeout. Sometimes it's more complex.

You're entitled to your opinion, your experience... just as much as I am entitled to mine.

I view unprofessionalism as trying to be something you're not. Using the wrong "tool" for the job.

A builder builds an unoccupied home. An HVAC pro fixes an occupied home.

It's extremely unprofessional to: _____________. (use the right "tool"?) --- what else did I miss something? Builders love to pound on stuff... use your imagination. LOL.

----------------

To the OP:

You're going to have to rely on someone to service this equipment well into the future. The advantage of being able to see this place in person... "it's an in person job" not a job for internet trolls who don't have anything better to do.

This is HVAC: anyone can do it. >>> you have to live with those results. <<< It wouldn't be the first time someone tried to do my job. Yet here I am 27 years later. (wink-wink)

If it were me... I would stick to 13 SEER AC (For CHICAGO climate). I seriously doubt I would select much more than 5 tons of AC for this house (3ton for D/S and 2 Ton for U/S). It's a 3 month cooling season. Efficiency: the AC isn't going to run enough to recoup it vs. what you pay for electricity. (That said: I don't have the ability to view this property in person... it's an in person job.)

Heating is different. Your climate is cold... you can save money on heat by reducing the waste. Modulating is the way to go. This "modulating" gas heat is very high end heating equipment. It will always use the gas you need to heat the home.

If you like fancy numbers: modulating is essentially in the 97%-98% realm of energy efficiency.

The problem: Equipment is in short supply. All brands. Manufacturing shut down, the world did not. If you need equipment / parts etc. and can find them, you better buy them before someone else does.

I service the Katy, Texas area.

@Austin Air Companie,

It might be a news flash that not everything is about you! My comment was in response to the OP's experience with four different replacement contractors--none of whom are helping the OP make an informed choice. Unless you're one of the ones competing for the job, you're not on the hook for the limitations of their "service."

@Austin Air Companie,

It might be a news flash that not everything is about you!

Ok, I'm in heating and air conditioning forum boards --- not builders are us. If you can't take the heat, stop following me to the attic in the middle of summer.

My job isn't one that I drop ship to a sub-contractor or GC for that matter. A common practice among builders. Let's make HVAC a commodity? Doesn't work so well a year or two down the road.

(I point this out for obvious reasons. Most that read what I post can read between the lines. People actually call me to do work... fixing pre-existing structures. I point that out to you Mr. Ross only because this continually flies over your head of understanding in a forum board "designed" for what I do. It's more about me, than you. If you go to a builders forum you can make the subject more about you. Wow!)

In a perfect world I would only see posts for my area... that said you don't service this area either. So not sure why you want to just form a "new argument"?

@Austin Air Companie

This thread is tagged for both the HVAC and The Old House forums. As a home designer, builder, remodeler, and a licensed professional engineer for the past 36 years, I think I'm well qualified to comment on either. Houzzers are always well served to wade through the comments and separate the facts from the fiction on any thread. The required amount of wading just seems to be more on HVAC threads.

I mentioned 5 tons, I'll do it again. 5 TONS of cooling split between the two floors.

I'll also comment on heating, 110K first floor and 70K second floor and both can be simple old fashion high efficiency furnaces or simple two stage units. I suggest a two stage 30/70 for the second floor because heat rises and who wants hot bedrooms to sleep in. All done on the cheap because it's slim you'll recoup the 12 to 15 grand difference for the high bids before they need replaced or house sold. DONE.

A well moderated website, which this is not and never has been, would have locked this thread down long ago.

IMPO

SR

Well, at least it's not a 10 year old post being resurrected!

LOL - True!

SR

@Austin Air Companie

This thread is tagged for both the HVAC and The Old House forums.

But it's more about HVAC. Ooops time to form a new argument. Something you're really good at Mr. Ross.

I service the Katy, Texas area.

"Well, at least it's not a 10 year old post being resurrected!"

My favorite absurd comments, sktn, come from the broken record who always has the same advice - "doesn't matter where you are, what kind of structure, how much your utilities cost or what your budget is, what you need is a ground source heat pump".

I see your comment rather odd Elmer. There is nothing wrong with ground source for cooling where A fox lives, in fact a prime location considering the consistent low ground temperatures and sktn just suggested an option. What surprised me is the mini split lovers didn't throw mini split out a dozen times...... Ooh, 8 mini splits will do it;

This is off topic Elmer but I see the Environmentalist California Kooks are losing the battle to stop a new desalination plant in Huntington beach after 20 years, and will produce 50 million gallons of water per day. As I see it this "just another summer" was enough to scare the coastal water board into approving the permit, so this is a summer is other than ordinary.

Oh, and after a decade of dickin' around with solar and wind they started building new geothermal energy plants in Imperial county, and say they also plan to extract lithium from the underground fluid. A double win, Electric and lithium for electric cars. So you see geothermal has it's advantages just about any where you live, so I don't understand why you're mocking Sktn.

It wasn't who I was referring to.

Desal plants make a lot of sense and I think over time there will be many more of them. There are several in operation in my state now, including one in Santa Barbara that was built, deactivated, and then brought back up again. Another in operation in Carlsbad.

But I think you've contradicted yourself- it is just a normal drought summer as we have ever few years. The desal plant in Huntington Beach has been moving along slowly for decades. The project was able to move forward because of proactive step taken by Gov Newsom to replace a member on the voting body who was against the project with one who was for it.

The California Coastal Commission, and other regional bodies up and down the state, have for too long been dominated by doctrinaire extremists lacking pragmatic understanding, who refuse to accept that barring and stalling reasonable proposals and advocating a constant status quo does no one any good. Approving nothing is no better than approving everything, there is a role to play that too often is missed. People with moderate views from both political parties are frustrated with their conduct time after time, have no doubt.

Geothermal power plants that capture heat from fissures in the earth's crust in seismically active areas have little in common with ground source heat pumps used for HVAC in structures, as I'm sure you know. Feel free to rant on as you wish.

Kevin9408: Elmer wasn't mocking me. We were both being a little sarcastic. I agree with his sentiment about a certain poster who thinks GSHP are the solution to everyone's problems - great if you are independently wealthy but otherwise they make sense in much more limited circumstances.

We settled on installing two traditional condenser and evaporator units from Armstrong, each 3 ton two stage 16 SEER and 2 45,000 BTU two stage furnaces.

So I guess the Bosch was no longer available in your area? Just curious, because the Bosch isn't expected to make a return to my area until Dec or January 2022.

It's kind of crazy being able to get certain things. Right now it doesn't appear this craziness is going to end anytime soon.