Adding electric heat to existing dwelling

[Birken Vogt]

I never thought I'd see the day when electric heat would replace gas!

There is a development near here, nice and large-ish houses, about 10-15 years old, everything gas that can be.

They usually all have 125 amp services.

I bet that will be fun when the powers that be decide to retroactively force all-electric on everyone there.

 

[ptonsparky]

I believe there are some tax incentives for installation of HP.

 

[Eddie702]

@Fred B

Here is my take after 46 years in HVAC & Electrical. Others will disagree

Any air ducted system in a house with stone walls will give very poor results and they will be very unhappy. You can heat the living crap out of the air but you are surrounded by stone "ice cubes",

There is actually a name for this it's called "cold 70" for your cold at 70 degrees.

A building like this will only work well with some type of radiation be it hot water steam HAHA or electric .

Heat pumps are all the rage and are cheaper to run and rebates and all but COMFORT is worth something.

If it was me and it has to be electric I would certainly use some radiation in the rooms you actually sit in Living, dining, family room etc for at least part of the load and then have some heat pumps to pick up the rest. Probably don't need to have radiation in bedrooms, bathrooms etc the heat pumps can cover that.

I was involved with a few jobs that were engineered by engineers, these were commercial renovations of brick and stone buildings and the bitching and complaining was non stop.

You could go in and put a thermometer on someone's desk, and it was 70-72 in there (sure by the air temp) but the ice-cold walls soaked up a lot of heat.

Just my 2cents

 

[PaulMmn]

I used to own a stone house. Walls only 2' thick, but that's just a matter of degree. The inside of the walls was plaster-on-rock. Outside was just rock.
Stone is NOT an insulator, no matter how thick! In winter, you could almost stick your hand to the inside walls. Summer, once the walls heated up, you hoped for cloudy days.
I built 'curtain' walls inside the upstairs. 2x3 lumber, with 6" insulation (the lumber was spaced away from the rocks). This made the upstairs nice and cozy! No drafts, just even heat. Helped in summer, reduced heat intrusion.

 

[Fred B]

Thanks for the input. My thoughts too was that the electric baseboard was going to be very expensive to operate even though the install might not be as bad.
Anyone use the IR flat panels? Got one customer that had these put in and is loving it.
Think most practical would be the heat pump with supplemental heat elements in them for real cold days or the IR.
Seen some that you can tie into the air duct on lower level then use ceiling cassettes split units for upstairs were you have attic space above for installation access. What does that sound like? Doable?

 

[jaggedben]

A HTG/AIR guy worth his money will be able to supply that info. Your customer should be looking for that.

They will be able to supply a very rough estimate, that is. But yes.

 

[jaggedben]

@Fred B

Here is my take after 46 years in HVAC & Electrical. Others will disagree

Any air ducted system in a house with stone walls will give very poor results and they will be very unhappy. You can heat the living crap out of the air but you are surrounded by stone "ice cubes",

There is actually a name for this it's called "cold 70" for your cold at 70 degrees.

A building like this will only work well with some type of radiation be it hot water steam HAHA or electric .

Heat pumps are all the rage and are cheaper to run and rebates and all but COMFORT is worth something.

If it was me and it has to be electric I would certainly use some radiation in the rooms you actually sit in Living, dining, family room etc for at least part of the load and then have some heat pumps to pick up the rest. Probably don't need to have radiation in bedrooms, bathrooms etc the heat pumps can cover that.

I was involved with a few jobs that were engineered by engineers, these were commercial renovations of brick and stone buildings and the bitching and complaining was non stop.

You could go in and put a thermometer on someone's desk, and it was 70-72 in there (sure by the air temp) but the ice-cold walls soaked up a lot of heat.

Just my 2cents

I'm not sure I understand. Sure, the stone walls act as a giant heat sink, but why would that effect different heating methods differently?

 

[PaulMmn]

I'm not sure I understand. Sure, the stone walls act as a giant heat sink, but why would that effect different heating methods differently?

The difference might be in how fast the heating system can react to changes in the air outside. My house had hot water and radiators to start with. Heat, but not as even as you might like. Once I insulated the upstairs, I changed over to hot water baseboards. Nice and toasty and -even- heat.
.
I'd suggest that at a minimum you glue at least 2" of foam insulation on the interior walls, and sheet rock over that. Yes, you'll have to re-do the switches, outlets, trim around the doors and windows, but the gain in comfort will be well worth it!

 

[Eddie702]

I'm not sure I understand. Sure, the stone walls act as a giant heat sink, but why would that effect different heating methods differently?

The stone or brick obviously gets cold from the outside and conducts that to the inside of the building. A stick-built house with insulation reaches equilibrium easier.

With stone or brick the outside walls stay cold all the time. Heat travels to cold and it's the large mass of brick or stone keep soaking up the heat. Obviously if there is sheet rock and insulation it will help a lot but the outside walls will still likely be cold. If your heating with air it sucks the heat out of the air quickly and makes the room field cold.

If you put any type of baseboard or radiators weather electric, hot water or steam to blanket the walls it can then be comfortable.

We had an office building with a conference room where 1 outside wall was glass block to let in light. The building was 15 years old and they could not use that room in the winter. They had roof top units for that room with gas heat and AC and it was always cold. That also had hot water radiation in other offices but none in that room. Someone added additional hot water coils in the duct work from the rtus (that already had gas heat) and it still didn't work. They had more heating capacity than they needed, and it still did not work. The glass blocks went from the floor to the ceiling.

180 deg water in the baseboard did the trick. Most furnaces and RTUs you don't even get 120 degree air, it's not enough to make a "Heat Blanket" Heat pumps may put out even cooler air.

So overcoming the room heat loss is one thing. The rate of heat loss to cold objects is something else.

It's like a hot radiant floor in reverse. If it isn't designed right and the floor has to run really hot to satisfy the room people can't stand walking on the floor its too hot

I had a carpenter build a box along the floor against the glass block with a front and a top. The front was 12" high and we mounted the hot water baseboard to the front. The hot water pipes ran inside the box over to a corner where they went up behind the ceiling to the HW piping (furred in) The hot air rising up from the baseboard "washed" the wall with heat and solved the problem

 

[mtnelect]

Find someone who can do a proper "HEAT LOAD ENGINEERING STUDY" to find out what the actual heat load of the structure is. You might consider going to double pain windows or increasing the insulation. Then make a decision on the new information. Go ductless with a Diakin.

 

[wwhitney]

I'm not sure I understand. Sure, the stone walls act as a giant heat sink, but why would that effect different heating methods differently?

I'm thinking it goes something like this. Numbers are approximate.

10" of stone might have an R value of only 0.5. A still air layer on the inside might have an R-value of 0.75. And the outside still air layer would have a lower R-value on average, due to wind disruption, maybe 0.25.

So the total R-value between indoor bulk air and outdoor bulk air is 1.5. If you want to keep it 65F inside, and it's 20F outside, that's a 45F temperature differential. Which means that at equilibrium the temperature gradient will be 30F per R. I.e. the inside face of the stone wall will be 42.5F, and the outside face will be 27.5F.

So then you have the "cold window" effect, but with a large cold wall rather than a window. The part of you facing that cold surface is getting less incoming radiant heat than it would get from an opaque 65F surface, so your net radiant heat loss towards the cold surface is more than usual, and you feel cold.

Cheers, Wayne

 

[junkhound]

Anyone aware of the ROI for going with heat pump vs oil or elec baseboard?

Case history for insulation of an uninsulated ceiling, then actual savings extrapolated onto HP vs. 80% gas trade:

Volunteer labor installed R-19 insulation in ceiling of parsonage, based on utiity bills, actually already paid for in first 9 months savings, Sept thru May, PNW weather, 5000 deg days. Existing 80% boiler and 73 cent/therm NG

Did do a trade, existing 80% gas vs. install a 3T air-air HP with COP of 3.3 using volunteer pro labor showed 49 months needed for payback at wholesale pricing for just equipment. Without volunteer labor suspect payback time for typical HO would be 2x to 3x that of church install with volunteer labor. Assumed constant prices, in hindsight gas stable, electricity has gone up, trade done 4 years ago.

Never tried to do the ROI as church spends money as it comes in or is available for capital improvements . Approved budgeted expenditures ALWAYS more than actual income, eh?

Guess one could say the ROI is market rate or CD rate after initial payback time.

 

[ptonsparky]

NY tax credit is a max of $2000 for HP units installed in '23.

 

[kwired]

Not according to the State of CA. Solar will produce plenty of electricity to provide heat, hot water, cook and charge cars on the cold cloudy winter days.

Southern CA has better chance of being true. Northern CA and higher elevations not so true and likely more people in those areas that would rather become a separate state from the southern portions as well.

 

[kwired]

There is a development near here, nice and large-ish houses, about 10-15 years old, everything gas that can be.

They usually all have 125 amp services.

I bet that will be fun when the powers that be decide to retroactively force all-electric on everyone there.

If they already have cooling it shouldn't take any more service to convert to a heat pump. If you have resistance backup heat however you may need to increase service capacity. You will need to increase service capacity anyway when they force you to use on demand electric water heating.

 

[James L]

Thanks for the input. My thoughts too was that the electric baseboard was going to be very expensive to operate even though the install might not be as bad.
Anyone use the IR flat panels? Got one customer that had these put in and is loving it.
Think most practical would be the heat pump with supplemental heat elements in them for real cold days or the IR.
Seen some that you can tie into the air duct on lower level then use ceiling cassettes split units for upstairs were you have attic space above for installation access. What does that sound like? Doable?

Here's the rub. HVAC company probably told them sometime like $18-20k or even more.

When hit with a number like that, it's very easy to overreact - screw that, I'll go all elec. - not realizing that if you were to upgrade their service and outfit the whole place with base heat and wall stats, they're gonna spend more that way. Radiant heat, too.

One thing to consider is that you most likely need contactors for each room because you'll exceed the wattage of an inline stat real fast. Unless they want dial stats on the units

Here's my suggestion, based on my experience:
I had a free estimate for a very small house (564 sf) for 1.5 ton heat pump w/ 8kw strips in the air handler. Reusing line sets, and me adding electrical for furnace. The price was $9,100

You know what I did? I found my system on eBay for $1,400 so I know that HVAC company wouldn't be paying any more than that. Even if they marked it up 50% that would be $2,100

That means they wanted $7,000 for 6 hours of work. You know, ain't no construction worker getting paid $1,200 per hour at my house.

I bought the units, and hired my son for $600 to install them. He was done in 6 hours. And with what I paid, I could do it 3 more times and still cost less than HVAC thugs wanted.

I would suggest to that customer to buy the units online and have a Craigslist guy install them. Even if they shoot craps, they can pay someone to fix it and still cost less than half.

HVAC thugs are like - but but but you'll lose your warranty. Who cares, if you can pay out of pocket 4 times and still cost less?

 

[ptonsparky]

....I'll be danged if I'll higher an EC when I can buy receptacles on line for $0.25. the kid down the street has a pair of wire strippers and a screw drive plus a he said he'd do it for a case of beer. I played hard ball. No beer until he's done...

 

[jaggedben]

Southern CA has better chance of being true. Northern CA and higher elevations not so true and likely more people in those areas that would rather become a separate state from the southern portions as well.

Sounds like nonsense derived from your held biases rather than from research.

 

[James L]

....I'll be danged if I'll higher an EC when I can buy receptacles on line for $0.25. the kid down the street has a pair of wire strippers and a screw drive plus a he said he'd do it for a case of beer. I played hard ball. No beer until he's done...

That's an over-simplification, and you know it

If you wanted an EV charger and install, would you rather pay an EV $7,000 installed, or buy the unit for $800 and find an electrician for $1,000

 

[letgomywago]

Here's the rub. HVAC company probably told them sometime like $18-20k or even more.

When hit with a number like that, it's very easy to overreact - screw that, I'll go all elec. - not realizing that if you were to upgrade their service and outfit the whole place with base heat and wall stats, they're gonna spend more that way. Radiant heat, too.

One thing to consider is that you most likely need contactors for each room because you'll exceed the wattage of an inline stat real fast. Unless they want dial stats on the units

Here's my suggestion, based on my experience:
I had a free estimate for a very small house (564 sf) for 1.5 ton heat pump w/ 8kw strips in the air handler. Reusing line sets, and me adding electrical for furnace. The price was $9,100

You know what I did? I found my system on eBay for $1,400 so I know that HVAC company wouldn't be paying any more than that. Even if they marked it up 50% that would be $2,100

That means they wanted $7,000 for 6 hours of work. You know, ain't no construction worker getting paid $1,200 per hour at my house.

I bought the units, and hired my son for $600 to install them. He was done in 6 hours. And with what I paid, I could do it 3 more times and still cost less than HVAC thugs wanted.

I would suggest to that customer to buy the units online and have a Craigslist guy install them. Even if they shoot craps, they can pay someone to fix it and still cost less than half.

HVAC thugs are like - but but but you'll lose your warranty. Who cares, if you can pay out of pocket 4 times and still cost less?

Just remember experienced trades are becoming the new high paying degrees. The tech jobs that were once high paying are now the 25ph jobs when the salary is broken down and they are not the low stress jobs they once were. Plus the computer science degree or software engineering degree cost 100k in student loans. Things have flipped for the time being