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PhoenixDown
FIOS is Awesome
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join:2003-06-08
Fresh Meadows, NY

PhoenixDown

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Nest & Tracking Heating Effeciency

Hi Folks

## Background ## I have a 2 family house heated by a boiler type of furnace. The 1st and 2nd floors have steam heated radiators. The basement is heated with baseboard heating on a separate zone. I have one thermostat, an older Honeywell unit with wands and manual set blue/red pins to determine when the heating should come on.

## Goals ##

My main goal is to reduce my monthly heating bills (if possible).

My secondary goal would be to help drive efficiency by having a 7 day programmable thermostat w/ internet access so I can pop the heat on as I'm heading home, or off if I already left.

## Questions ##

I keep hearing about the Nest. The reviews seem generally positive and a friend of mine loves the thing.

1 - I understand that the system is self learning but I am wondering if it can accept multiple sensors and distinguish between say myself and my tenant and if it can sense the temperature in different parts of the house and incorporate that it into the feedback loop.

2 - I saw that the nest provides some detailed reporting on when the system is turned on/off. I am trying to figure out if there are any savings from turning the system on / off at various points of the day or if it is more cost-effective to just ensure the temperature in the house never drops below a certain point.

a) Are there any testing methodologies for this kind of thing?
b) Would something like the Nest help in the tracking and tweaking of such settings?

3 - I do not have central air but as a bonus, I am wondering if I could use something like the Nest to monitor and track window or portable A/C usage. Its not a need but if I am going to buy a new A/C this summer, I'd as soon buy one that could plug into the system and help keep energy costs down.

4 - What main brand models is the Nest competing with? I don't mind looking at other solutions if they are a better fit for what I am attempting.

Thank you folks as always for your guidance and opinions
rgoltsch
Premium Member
join:2001-03-04
Bradenton, FL

rgoltsch

Premium Member

I replaced my 2 year old 3M Filtrete wifi thermostat with a Nest last month. Both offered wifi connectivity, but the Nest blows it away with usability and "smartness"

The old Filtrete did a good job of turning on and off my furnace at four different times during the day. I could program it from my iPad, iPhone or computer. I set it to go on a 6 AM, it went on at 6AM. I told it to go off at 8 AM, it went off at 8 or if the temp was reached.

Now, the Nest is a whole different breed of thermostat. First, looks.....it looks like those old round thermostats mom and dad had in their house for years. Except it is polished stainless steel.....with a color LCD screen. All you do to use it is turn it, or lightly press it to make things happen. It is expensive and feels like it, not a cheap feel at all.

You can wire in the new Nest and start using it right away. Simply go to it when you want the heat up, and then go back and turn it down when you want it down. After a week or so, it learns your patterns and sets a schedule. Or you can use the Nest itself to set a schedule, or your iPhone, or iPad, or computer browser.....you get the idea. I see there is an Android app too, but I have never used it.

Now here is where the sweetness comes in. It learns that you want the house at 68 degrees when you wake up at 6AM. Well, during the week before, Nest was monitoring your temps as the boiler was on, and took note of how long it takes your house to warm up. So the second week, the heat might kick on at 5:15 in what it calls "preheat mode". When your feet hit the floor at 6:00AM, the house is already warm. I sed to have to guess how long it took for my house to warm in the morning so it would be warm when my wife got up earlier than me for work.....no more guessing. We just tell it when we want it to be a certain temp, it does the rest.

Another thing Nest does is it monitors your outside temp over the internet (You told it your zip code when you installed it). It sees that the temps are really cold outside tonight, so it may need to turn the heat on sooner.

Each day you can log in with your devices to see how many hours your boiler was being used, and at what time. It shows a 24 hour bar graph detailing when your boiler was on and off. We had a few days of warmer weather here in NJ, and it even noted that decreased use of boiler was due to unseasonably warm weather.

I have yet to receive a monthly report, as I have only had mine installed for three weeks (My wife got it for me for Christmas...yes, she knows me pretty well).

One neat thing I noticed yesterday is when you go up to the thermostat and raise the temperature, is the Nest displays the current temp, your setting, and some text detailing how long it thinks the house will take to warm to the new temperature.

If you have specific questions, let me know.....I will be happy to share what I know. I love my toys, and this is one really neat toy.

jrs8084
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join:2002-03-02
Statesville, NC

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Click for full size
Learned Schedule
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Runtime
A nest isn't going to magically save you more money than any other t'stat really can. It just makes it really easy to adjust it and it senses when you are away. So, for people who never accurately programmed their old t'stats or never turned the temp down when they leave-yes, those people will likely see some energy savings. But, it isn't going to bring vast savings for a halfway accurately programed t'stat.

That said, I programmed my old t'stat, and I will tell you that my nest IS more accurate (program) because it is learning from my true behavior vs. what I think I should set it for. I know I am turning it down much more at night than I used to.

Also, how well it works in your setup is variable. If your heat has a very slow recovery time, then you are probably reluctant to make major temp swings.

A nest can't differentiate between you and your tenants. A body is a body. I believe you can incorporate them with other nests for multi zone systems-you will have to check with nest. They are not going to monitor other sources of heating or cooling like window units.

The nest is great-I love mine. Who knew a t'sat could be fun? But keep in mind it is a learning thermostat, not a programmable. Sure, your can "program" it via the web. But the point is you just turn the dial as needed, and it will learn and predict. This. you don't have to turn the heat up before you get home-it will quickly figure that out.

I attached screenshots showing how you can adjust the program (drag dots) and how it shows runtime/temps and if you or the nest made the changes.

ArgMeMatey
join:2001-08-09
Milwaukee, WI

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said by PhoenixDown:

I have a 2 family house heated by a boiler type of furnace. The 1st and 2nd floors have steam heated radiators. The basement is heated with baseboard heating on a separate zone. I have one thermostat, an older Honeywell unit with wands and manual set blue/red pins to determine when the heating should come on.
...

2 - ...I am trying to figure out if there are any savings from turning the system on / off at various points of the day or if it is more cost-effective to just ensure the temperature in the house never drops below a certain point.
...
4 - What main brand models is the Nest competing with?

I'm confused. I am guessing you have 2 or 3 thermostats, but I don't know if your tenant lives in the basement or on the 1st or 2nd floor.

Yes, the Nest is a thing of beauty and by all accounts it works pretty well as long as you understand what it can do.

#2 can be a point of considerable debate bringing in terms such as thermal mass and air changes per hour. In short, it has to do with the rate of drop of the temperature and the length of time you are keeping the temp elevated vs. reduced.

#4 The Radio Thermostat aka Filtrete is out there but doesn't have the finesse of the Nest. I have one. While it works well enough, it's got some, shall we say, endearing features so I cannot recommend it.

The Honeywell TH8320WF1029 I think has AIR, a proprietary recovery algorithm. It also has a heat anticipator algorithm if I recall correctly. It doesn't have the fancier features of the Nest, but online it's priced closer to the Filtrete while offering superior engineering.

There are plenty of others out there such as Ecobee but everything I've seen is farther upmarket ($$$$) from the Nest and many are sold only through traditional suppliers.

If you have a zoned system, do you have a zone controller that activates valves and turns on the boiler and pump(s)? I am not sure if Nest can handle tracking concurrent calls for heat among multiple zones, meaning that if you just added the runtime on two Nests connected to the same boiler, you likely wouldn't have an accurate figure.

The chief advantage of the Filtrete is its open interface, which was attractive to me. However they still have work to do in firmware and features.

cowboyro
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join:2000-10-11
CT

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The Nest won't save you anything that will make the slightest real life difference over a regular programmable thermostat - unless you have no insulation and turning the heat off even for 1 hour will cause your house to cool significantly.
You only achieve savings when you allow the house to cool, as heat losses depend on the in-out temperature difference and lower indoor temperature means lower losses.

PhoenixDown
FIOS is Awesome
Premium Member
join:2003-06-08
Fresh Meadows, NY

PhoenixDown

Premium Member

Tenants live on the 2nd floor apt. It's one thermostat and if added a sensor to thier apartment I wonder if I'd ultimately confuse the thing lol.

That said I like the reporting nest seems to provide. I think the insite it offers may help

Installation seems simple enough.

djrobx
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join:2000-05-31
Reno, NV

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I love my Nest.

If you want a beautiful, intuitive, "luxury" piece of modern technology to run your HVAC, go for it. It's all about the little things - the way it feels and clicks when you turn the dial to change the temperature, or how it "wakes up" when you walk up to it. It's not an ugly white box on the wall. The web UI for programming is very easy too.

Don't buy it for the potential savings though. You can get most of the energy saving features in cheaper packages. Auto-away is nice but you'll get better savings if you manually set it to away as soon as you leave.

I understand that the system is self learning but I am wondering if it can accept multiple sensors and distinguish between say myself and my tenant and if it can sense the temperature in different parts of the house and incorporate that it into the feedback loop.

Nest only "links up" to other Nests, which would be cost prohibitive for what you describe. I wouldn't be surprised to see Nest sell something along these lines in the future though. I'd love this myself - I have a two-story with only one blower, and keeping the upstairs and downstairs comfortable could use some extra smarts.

I saw that the nest provides some detailed reporting on when the system is turned on/off. I am trying to figure out if there are any savings from turning the system on / off at various points of the day or if it is more cost-effective to just ensure the temperature in the house never drops below a certain point.

a) Are there any testing methodologies for this kind of thing?
b) Would something like the Nest help in the tracking and tweaking of such settings?

The smaller the differential between the internal and external temperature, the slower energy leaks out.

»fivepercent.us/2009/01/2 ··· ow-myth/

The only good reason to maintain a minimum or maximum temperature is to protect things from freezing (pipes) or melting (candles).

In any event, the Nest energy reports will allow you to experiment and get nice feedback about what impact the changes you're making have on your energy bill. You can see it down to when it cycles on and off, or just cumulative daily usage.

I do not have central air but as a bonus, I am wondering if I could use something like the Nest to monitor and track window or portable A/C usage. Its not a need but if I am going to buy a new A/C this summer, I'd as soon buy one that could plug into the system and help keep energy costs down.

Certainly should be do-able as long as you buy something that can utilize 24v line level connections (connect to Rc and Y). And even if it did not, you could rig something up with a 24vdc transformer and a relay.

What main brand models is the Nest competing with? I don't mind looking at other solutions if they are a better fit for what I am attempting.

3M/Filtrete, Honeywell wifi VisionPro, various Zwave solutions (Schlage/Trane)

jack b
Gone Fishing
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Cape Cod

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The only way you could use your Nest or any other low-voltage thermostat to control a room AC is to hook up a suitable load-rated relay inline with the unit's power supply outlet.

This is doable, but the main key to it's success or failure is if the AC unit itself resumes cooling at IT'S setpoint, after line voltage is interrupted and restored.

A lot of AC units will not even restart automatically after a "power failure" or will run cooling @ 76 degrees, or such.

For a remote thermostat to do the job, you would need to set the unit as low as it goes and allow the remote stat to cycle it on and off.

I've done this setup before and it can work!

ArgMeMatey
join:2001-08-09
Milwaukee, WI

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said by PhoenixDown:

Tenants live on the 2nd floor apt. It's one thermostat and if added a sensor to thier apartment I wonder if I'd ultimately confuse the thing lol.

Are your tenants complaining about too much or too little heat? I am assuming you are including their heat cost in the rent.

Putting a remote sensor in a separate dwelling will simply shift overheating or underheating to the other dwelling.

It's not clear to me if a remote sensor is available. Regardless, unless they're averaging or they've got some magic filling in their silver donut, the remote sensor would then essentially allow you to control the heat based on the temperature in their unit.

The best solution is zoning, but setting up zoning could be expensive depending on your existing piping. There are existing stats that would let you put the remote sensor in their unit and still control the heat from your unit.

jack b
Gone Fishing
MVM
join:2000-09-08
Cape Cod

jack b

MVM

There is no zoning retrofit to split an existing residential steam system that is financially justifiable. It's the nature of the beast.

If a landlord was to consider any capitol project, installing separate boilers with each apartment paying their own heat is the only way to go.

The entire system would have to be ripped out and start over from scratch.

ArgMeMatey
join:2001-08-09
Milwaukee, WI

ArgMeMatey

Member

said by jack b:

There is no zoning retrofit to split an existing residential steam system that is financially justifiable. It's the nature of the beast.

If a landlord was to consider any capitol project, installing separate boilers with each apartment paying their own heat is the only way to go.

The entire system would have to be ripped out and start over from scratch.

Sorry I missed the "steam" part.

I agree, if it is actually steam, i.e. one pipe to each radiator, and the system was installed intended as one zone, the cost to zone would be well beyond that of a thermostat. It would be easier to install mechanical thermostats on each radiator in that case, to keep any area from overheating.

I also agree that the chief benefit of learning systems is increased comfort. Just about everyone who can get one, has a programmable stat now, so I would doubt any energy savings unless you've previously been leaving a manual stat on the same setting.

People living alone who are motivated to track their statistics and reduce costs can easily do so, and the Nest makes that a lot easier. But in my experience living with other people, there's usually one who's hot and one who's cold and if you're lucky, a tiebreaker. (For more info just google my good friends, Carl & Barb Kulick.)

pende_tim
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join:2004-01-04
Selbyville, DE

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Reports look pretty, but I am not sure they are detailed enough for my needs.

For a 2 stage Heat Pump with Single stage resistance Aux heat, can the Nest report the individual run times for First, Second and Aux heat? or Does it aggregate it all into a single runtime number?
TheSMJ
join:2009-08-19
Farmington, MI

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Mind elaborating on your opinion of the Filtrete thermostat? I was thinking of picking one up for my new house.

norbert26
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join:2010-08-10
Warwick, RI

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said by PhoenixDown:

Hi Folks

## Background ## I have a 2 family house heated by a boiler type of furnace. The 1st and 2nd floors have steam heated radiators. The basement is heated with baseboard heating on a separate zone. I have one thermostat, an older Honeywell unit with wands and manual set blue/red pins to determine when the heating should come on.

Lets take a look at the OPs first post. He says the 1st and 2nd floors are on one zone. I am going to assume these "steam" radiators are cast iron. (more on that shortly). Then the OP said the basement is on its own zone with baseboards. OK so we have first and second floors on one zone. That includes the APT on the 2nd floor. One T-Stat controls those floors. I assume that T-Stat is on first floor. In the basement there is another zone on its own T-Stat. This zone is served by baseboards. This is all on one boiler having TWO zones. This does NOT sound like steam heat to me. I have a hunch this is hydronic / force hot water / circulating hot water heat. Older hydronic systems used cast iron radiators that looked like steam heat but were really forced hot water. Since this seems to be an older system i am leaning towards the basement zone being on a separate pump rather then a zone valve served system. Regardless the issue is the tenant is on the same zone as the first floor and any "management" the OP applies will affect the tenant as well. So lets say the OP goes to work and lowers the heat the tenant would be affected as well. The tenant's heat would need to be separated onto its own zone. This may and may not be viable depending on the plumbing . If the second floor can be easily split off another (third) zone could be added and tenant have their own T-Stat. A more costly option if plumbing was right is second floor could be put on their own boiler and they pay their own heat . Either of these would make managing the land lord zones doable in some form or another without affecting the tenant.
NOTES: If i am assuming wrong and first and second floors are STEAM heated then i am trying to figure out the basement zone . The OP after a reread says ONE T-Stat . Does this T-Stat control the basement too ? Usually each zone has its own T-Stat. Pics of one of the 1st floor radiators would be helpful and a pic of the boiler would be helpful to determine what kind of boiler this is. Also a pic of the baseboard in the basement zone.
NOTE #2: It is possible the OP means the basement zone is NOT served by the boiler at all but electric baseboard heaters. In this case the 1st and second floors could very well be served by a steam boiler .

PhoenixDown
FIOS is Awesome
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join:2003-06-08
Fresh Meadows, NY

PhoenixDown

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Sorry for the confusion -- its one thermastat. The original system was built at the time of the house and my parents added baseboard heating maybe 15 years ago. We looked at separating out the apartments but it was cost prohibitive.

I always thought the first and second floors were served by steam as there are little release values that let out the steam and control the system pressure but I could be mistaken

It was originally a coal-powered system that was later converted to natural gas and finally replaced by a new (relatively speaking) natural gas boiler.

norbert26
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join:2010-08-10
Warwick, RI

1 edit

norbert26

Premium Member

said by PhoenixDown:

Sorry for the confusion -- its one thermastat. The original system was built at the time of the house and my parents added baseboard heating maybe 15 years ago. We looked at separating out the apartments but it was cost prohibitive.

I always thought the first and second floors were served by steam as there are little release values that let out the steam and control the system pressure but I could be mistaken

It was originally a coal-powered system that was later converted to natural gas and finally replaced by a new (relatively speaking) natural gas boiler.

Thank You that cleared my confusion. It indeed does sound like steam now that you described it. There's not much you can do there to separate the tenant off that system . Any heat controls / learning T-Stats would affect the tenant as well as you. If you did go with something like the nest you could HOWEVER the tenant would have to be figured in to the settings.
Edit: Typo

PhoenixDown
FIOS is Awesome
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join:2003-06-08
Fresh Meadows, NY

PhoenixDown

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Its an interesting question, -- can a system such as Nest work with remote sensors and can those be configured into psuedo-zones?

The max and min temperatures would need to be remain a constant and the tenants wouldn't have any additional control over that (unless I gave them web access which im not) but it would be helpful to factor when they are in or out into the equation.

Also, if a tenant leaves and I get a new one, I would like to delete the data from the pseudo-zone so Nest would re-learn that area but not impact what it already knows based on the primary zone and how the heating system operates.

jack b
Gone Fishing
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It's quite common to circulate steam boiler condensate for heating a separate zone, essentially it's a zero-pressure forced hot water loop.

There are very specific piping requirements which must be followed when installing this type of zone heating for it to work properly.

Anonuser
join:2003-01-03
Milwaukee, WI

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With nest, you can have multiple nests in a home, they can network together as remote zones. See their site for more info.

Sorry, dont have more time to reply in detail.
TheMG
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Canada
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said by jack b:

The only way you could use your Nest or any other low-voltage thermostat to control a room AC is to hook up a suitable load-rated relay inline with the unit's power supply outlet.

You're right, getting such a thing to work well with a modern electronically-controlled A/C unit can be a big pain.

I've run into this before. At work we had an A/C unit replaced at one of our sites where the A/C unit was being controlled with a contactor as part of a more complex HVAC system. The new unit has electronic controls, and would default to "OFF" after power is removed from it.

We actually had to get a firmware modification from the manufacturer of the A/C unit to resolve that problem.