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Deual fuel set-up is great, but not for everyone.

2124 Views 16 Replies 2 Participants Last post by  flashheatingand
I have suggested duel fuel setup for a lot of people, but now realize it isn't for everybody.

For example: If nobody is home during the day, just night time, there is no sense in using the energy. Or, if the homeowners are not interested in how to program the t-stat (they like simple controls), they aren't ideal. Or the elderly, as they tend to like higher supply temperatures.

But, they are great for day-cares, storage rental offices, shoot, just about any buisness location. The energy savings is significant. In summary, it is a great appliance/ setup but, the saying "know your audience" comes to mind.
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So if you install a regular furnace. And no one is home during the day. Its not worthwhile running the furnace?
If its worthwhile running a gas or oil furnace, then its worthwhile running a heat pump.

No special programming needed for a dual fuel system.
You as teh installer can set it up to locj out tehheat pump at 40 or 45. What ever temp that is desired by the customer. So they have a warm enough air discharge.

There are those customers that will never be happy with a heat pump.

We were all lucky. Energy prices didn't sky rocket this past winter.
But, as the economy slowly improves. Energy prices will climb again.
People with dual fuel systems will be very happy with their lower heating bill.
I do not believe it is worthwhile to run a furnace while nobody is home. Granted, you don't want the house to get to 50 degrees, but there is nothing wrong with letting the house get down to 60. Convection heat is quick to come and quick to be lost. Basicly we heat the air, not the building. A heat pump in general simply keeps up with the load, but doesn't "warm" the house. It doesn't take too long to bring a house from 60 degrees to 70 with a gas furnace, but virtually impossible with a heatpump. It is actually better that the furnace run long and steady than opposed to several quick bursts per hour.

Lockout the heat-pump at 40 degrees, and the appliance will primarily operate during the day-time hours. Which is great if the space is occupied, but not worthwhile if vacant. Just my humble opinion

So explain whats wrong with using the heat pump to maintain that 60° during the day. When no one is home, instead of using the more expensive gas or oil furnace.
The heat pump still pays for itself in a fairly quick time period

Heat pumps not being able to recover from set back is a myth.

If the heat pumps balance point is 35°F. Then it will have no problem recovering when the outdoor temp is 40°F.

While you may not believe in keeping a house above 60° during the day while no one is home. I'd venture a guess that not all of your customers agree with you.

Lots of nights that the outdoor temp is 40° or above.
Hey BK,

If nobody is home, there is no use in using energy to heat it. Ok, there are exceptions but I am generalizing. If customers do not agree with me, thats fine. Do what they think is right. From an energy efficiency and economic "payback". It's what I find from both personal and professional experiences.

Radiant systems are a different breed of cat. Convection heat is easy come, easy go. If you could only run the system only at night, why not? Many heating systems for one reason or another will heat a room by 3 degrees within a half hour.

Lets say you can bring the temp up 7 degrees an hour. Would it not be better on the equipment to run for a straight hour, as opposed to operating for 5 minutes 3x an hour? Either way you are using the same amount of energy, it's just one is being utilized more effectively.

I came acAs for the number of evenings that are between 40-50 degrees, there are some, it's not that rare, but not enough to justify the extra expense when cash is tight.
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I came acAs for the number of evenings that are between 40-50 degrees, there are some, it's not that rare, but not enough to justify the extra expense when cash is tight.

Lots of tomes I do turn my heat off in the winter.
Gone for 14 to 16 hours no real need to maintain temp.
Takes more then just one heat cycle to warm up the walls though when I do that.

People have heating systems in their homes that can heat the house to 70 or 74 what ever temp. So they can be comfortable.
If systems were installed for efficiency. then they would only be sized to heat the home to 60.

But, none of that has anything to do with a dual fuel heat pump.
What I am trying to say is that if a family/space is vacant from 8:30-4:00 on a regular basis, the benefit of duel fuel isn't as great. Also, I don't think it's a good match for the seniors, but thats just me, and I wonder if others agree or disagree.

That final sentence shouldn't have come up, whoops, nothing really worth repeating
Your using the assumption. that people won't accept a lower discharge air temp from the registers.
Some won't.

But, many more will. Specially when they see the savings they get.
There are more then enough nights that the temp is above a heat pumps balance point. That it will both heat the house an save the customer money.

(Saving money is why you don't believe in heating a house when no one is home right)

You ARE looking for excuses not to use duel fuel.
Can tell by your other post you made about heat pumps.

I have dual fuels in that the heat pumps balance point is 20°F. They save a lot on there heating bill.

I have others in. That the balance point is 35°F. They also save a good amount of money on their heating bill.

The increase in cost to install a dual fuel heat pump. Instead of just A/C and a gas or oil furnace is not a lot.
So it doesn't take long for a person to recover the money that the heat pump upgrade cost.

If you want to use the premise of not needing to keep the house warm during the day. Those same people that would agree with that, don't mind a cooler air temp from the registers.

Newer heat pumps have higher output temps then older ones did.
Higher end systems have the ability to slow the blower to a warmer temp yet. If the customer desires.

Some people will never like a heat pump. They are becoming fewer in number by the day.

Instead of trying to find other people that are against heat pumps. And will agree with you.
Check into what new heat pumps are really like today.
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I never was hating on duel fuel, so stop jumping to conclusions. I think they are great and reccomend them as well, but not too everybody across the board. I have taken time to check out how they perform, and they are great at a certain range. It doesn't fit everybody's lifestyle. All I said is to know your audience.

I mentioned certain types of people who probably will not benefit as much as you claim. I also mentioned lots of situations in which duel fuel is ideal. As a heating professional, I was stating to others an opinion. Which was as stated earlier that they are not for everybody despite the 25% lower operating cost.

As for the saving money by not heating the house while vacant was not mainly due to saving money. It's because I would rather that the appliance run steadily for 30-45 minnutes as opposed to cycling on and off all day. I am not certain as to weather "my way" is cheaper on the bill in the first place. It's just less wear and tear on the equipment.
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You have in other post talked against them.

So I'm not jumping to conclusions.
No, I am not sold on the concept of infinity controls, HD t-stats, wireless stats, and some products that make crazy claims.

The thing I think you are talking about was in regards to installing the coil on the return as opposed to the supply. I still think it's a better way especially with a furnace that has a stainless steel he with the coil in the return, you can actually run both applianaces simultaneously, Around here, the a/c runs about 2 1/2 months a year, heat pump will run about 7.

Honeywell now has a stat that will take care of the scenario I was describing in which the stat will lockout the compressor when the gas come on. Cool. I never did install the coil in the return, just inquiring to others.
Honeywell has had those type of thermostats out for some time now.
Along with White rodgers.

Even SS heat exchangers are not immune to condensate in the primary heat exchanger.
They will pit and rot out.

They aren't made for moisture to lay in them for prolonged periods of time.
Ok, The only t-stat that I was aware of was the vision pro 8000, and you could lockout the compressor at x as the odt. But that did not account for certain situations. But I digress. Bottom line is I do not hate on the duel fuel concept. Or heat pumps for that matter.

I am also for products that do benefit the homeowner. However, I think some products make crazy claims, some outfits make outrageous promises, all in the name of the $$. When I question the concept or product, I am not looking for people to agree with me. I hope for answers to clarify things so I can try to sell them with being able to sleep at night.
You need to attend more training classes and seminars.

Staying up with improvements on equipment, and technology is what we get paid for.
And should be charging our customers for staying up with technology and other mechanical improvements.
I attend all the seminars and classes that are locally available. Most of the seminars end up being dog and pony shows with the speaker hawking his wares. Nevertheless, I show up just to learn something new. I don't mind spending money on courses, but usually the instructor is overwhelmed by the number of students. Actually some of my comments are based on what came across the seminars.

I like use this site as a learning aid. As I think the best source of info comes from other hvac guys.

I have, no pun intended, beenthere. I have a few calls to go to now, but look forwardsto your comments.
All free seminars are D&P shows.
And a lot of the seminars that you pay to go to, canalso become D&P.

Try classes and seminars sponsored by ACCA, or RSES.

They will be more for the technical end of equipment and focus on what is and is not practical.
I would be open to those, however, they don't come to this neck of the woods. With work, honey-do's, and other things, there isn't time with the travel. As of now, I like to talk with other hvac guys
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