All-electric house - will coned provide enough service
We’re looking at the pros and cons of an all-electric house. I keep looking at the total necessary service and it seems like it’s likely to be more than Coned will provide. I’m wondering if anyone has any experience in asking for 300, 400 or more? It’s my sense that to do all electric for a 2 family is going to require 400+ Amps from the street.
thanks
arewedoneyet
in General Discussion 4 years and 4 months ago
16
Please log in, in order to post replies!
16 replies
nyc_sport | 4 years and 4 months ago
We had a 40 gallon electric tank heater installed during the year-long period that ConEd was kind enough to turn off the gas to our apartment building. Worked fine, cheap, and electric draw was manageable (plugged into the 220v dryer outlet).
hkapstein | 4 years and 4 months ago
Well if you had a 4 family or 10 family coned would provide service for it would they not? And that could be a lot more than 400 amps. You would need to have your electrician file a load calc with coneds alteration dept. Coned will decide how much service you need to support the appliances you applied for. Then they will provide it. I suppose there could be a problem if the transformer is overloaded. I think it’s unlikely, but if that were the case it would probably end up backburnered for years until the infrastructure could be upgraded, but I doubt it’s likely. You will definitely need to run a new conduit and service line to your property line, and most likely the end of your areaway. Wires and conduit that can carry 400 or 600 amps are expensive as would be the labor to install them, between coned and your electrical contractor I’m sure that cost would be significant. Meter pans, panels, switches and breakers rated over 200 amps cost significantly more money so if you can put some stuff on your common meter you can have up to 3 200a meters for 600 amps. Many electric ians don’t like putting in a 400amp panel and dealing with the service upgrade, so you have to find someone who wants the job, but I don’t think you’re going to have coned tell you no.
Now if you want a tankless condensing gas boiler in a 2-family, architects correct me if I’m wrong, but I believe you can avoid the mechanical room completely if the boiler is direct vented, which I think you would want anyway. Direct vented or not, you’d almost need to exhaust it on the roof, so you need a way to run the exhaust.
arewedoneyet | 4 years and 4 months ago
We’re basically comparing/contrasting on-demand water heaters – either electric or gas and electric tanks. Some of the questions we’ve had trouble answering include:
– how much power will Coned actually provide? 200, 300, 400A?
– what are the requirements for a mechanical room if we go with condensing gas on demand? we’re clear about venting but less so about how big a room, what sort of fire-proofing, metal door, make-up air?
Thanks,
David
hkapstein | 4 years and 4 months ago
Maybe they’d have room for at least a 30 or 20 gallon storage tank to buffer the flow that way the water wouldn’t be impacted if someone went to wash their hands or do a load of laundry during a shower.
Guest User | 4 years and 4 months ago
i just looked at the install manual for the tempra 36…they now require three separate 2 pole breakers so perhaps they are better than they were years ago when i installed one…i still think that it is way wiser to go for a tank type electric heater since it requires maybe a 3′ x 3′ footprint with no venting necessary
Guest User | 4 years and 4 months ago
@arewedoneyet – you have to get the plumber/mechanical engineer to do the math or you do it yourself. You need to figure out how these will vent as well if choosing gas.
Guest User | 4 years and 4 months ago
I installed a tempra in a 2 br 1 1/2 bath in soho years ago… mid winter it was absolutely insufficient for even a single shower with a rainfall shower head. After back and forth with tech support the only solution was to choke the flow through the unit by about 30 percent. As I remember it was the unit that took a three pole 60 amp breaker. Go with an electric tank type water heater
arewedoneyet | 4 years and 4 months ago
I’m also assuming that the marketing is optimistic and that these will need to be over-specced. I’m hoping I can use one of these units for a 2-3 bedroom apartment but I’ll admit I’m nervous about whether these German units, while well made, are really aimed at a non-US market that has somewhat different hot water expectations than we do.
For those of you still paying attention do you have any thoughts/recommendations on a good setup for a double-duplex townhouse with no room for proper mechanical rooms? It’s a 4 story including garden with no cellar of about 19×35.
brooklyndempsey | 4 years and 4 months ago
@janedrew we put one in just to service the garden apartment during construction–rated nominally at 20KW. It was enough to run a shower, but not much more than that, and even then was not super hot in the winter. We were living there while the rest of the construction finished so it was a stopgap–still plumbed in but we keep it off and use a normal gas boiler/hot water tank that serves the whole house. My main takeaway was in NYC, compared with the marketing material the units would need to be even bigger than you’d think from reading the brochure.
hkapstein | 4 years and 4 months ago
I mean if it’s one or two people living in the unit it might be OK if you’re aware of the system. A typical tub could fill at 7gpm, so you’d need to open the hot water only half way in winter to get warm water. While filling the tub, no other faucet would get hot water. Will that kill you? Probably not. Maybe tenant might complain if it happens to them. But a 45 or 60 gallon storage tank isn’t that big, it would fit in a closet.
Guest User | 4 years and 4 months ago
@lmiller Do you have one for the whole house or multiple? I may have slightly oversized mine but it’s for a duplex.
brooklyndempsey | 4 years and 4 months ago
I have a smaller version of this type of electric on-demand demand water heater, that we used during our renovation before our gas boiler was commissioned (and kept installed but turned off, as a backup). As Urbandad points out our area has low water temperatures and the units are also derated somewhat due to the lower voltage in NYC. It worked OK, but they produce less hot water than you’d think from reading the marketing material. As a homeowner–personally I wouldn’t use this type of heater for a whole brownstone. The current demands are huge. I would bite the bullet and build the mechanical space you need.
hkapstein | 4 years and 4 months ago
I’m not sure that unit is the best way to go. Look at the specs. It claims it can flow 4.5gpm at a 55 degree temp increase. A regular shower will draw 2.5gpm, so if the water temp is 40 degrees(not uncommon in winter) two showers would run at less than 95 degrees which would feel cold. Keep in mind the 55 degree spec is probably better than the actual performance would be taking into account scale in the unit, cooling in the pipes on the way to the shower and other non-ideal conditions. Taking a shower and run the washing machine, dishwasher, or kitchen sink would probably also overload the unit. I’d suggest trying to get an electric tank or heatpump tank unit. You could use a combination of point of use water heaters and that unit, or maybe a small storage tank or something, but that would be complicated, I’d talk to a mechanicals engineer to make sure everything will work. But if it were me I’d try to get a tank heater for this setup. I’m not sure you need a mechanical room for an electric water heater, probably not would be my guess, but you’d have to check. But if y ou really want a tankless unit like that, you’d probably need a bigger than normal service. I believe coned will upgrade the service above 200 for you, but you’d have to talk to your electrician who will be handline the paperwork, and submit the load calcs etc.
arewedoneyet | 4 years and 4 months ago
Thank you – the clarification on the phasing helps a lot. The specific item that’s worried me are the electric on-demand hot water heaters. We’re looking at using them because of the space savings that not having a mechanical room provides and the advantages of no combustion, venting, etc. However, units like this: https://www.supplyhouse.com/Stiebel-Eltron-239225-Tempra-36-Plus-Whole-House-Tankless-Electric-Water-Heater?utm_source=bingad&utm_medium=shopping calls for 150amps and we need one for each unit in the building.
I haven’t found heat pump water heaters that will work with air below 40 degrees. Do they exist? I’ve been intending to use heat pumps for HVAC but didn’t think we could for other purposes. I wish we could do geothermal ;).
Thanks again
Augustiner | 4 years and 4 months ago
Use heat pump water heaters and heat pump dryers
hkapstein | 4 years and 4 months ago
First, make sure you understand how electric phases work. You have two hot leads coming in each at 120v to neutral. If you cross the leads, you have 240v. If you have a 200 amp service, you have two phases that can carry 200 amps at 120V, so you really can operate 400 amps at 120 volts, or 200 ampts at 240V. Now my guess is that’s actually enough for you what you need. If you’re using heat pumps, the heating load might be around 30 amp per floor at 240v, assuming everything is maxed out and running simultaneously, and the reality is the 30amp minimum circuit ampacity spec is oversized by probably 25%. And you have two electric stoves(40A, maybe 50), plus 2 dryers, plus misc loads. Ok so your units, 200A at 240v. You need 3x30A for the heat + 40A cook + 30A dry plus 30A water heater. You’re probably ok. You might put the water heater on a common PLP meter and that would give you a little more room. The tenant would have 1×30 heat + 40 stove, so you could proably get away with a 100A service.
So 2 or 3 meters at 200A, probably 1 at 200, and 2 at 100, yes they will do it if your electrician submits the load calculation properly.