TRVs on ALL rads .. even near t-stat concept

jpf321

i'm really considering TRVing ALL rads, even

near the t-stat and having a second (independent) t-stat on 3rd floor

which could also call for heat .. that would work right?



the reason that we don't TRV near-t-stat-rads is because they might be set below T-stat setting and

therefore the t-stat is always calling .. if you have a second

independent t-stat in a different location, you could TRV all rads couldn't you?



taking it a few steps further (although not my intention) you could put a t-stat in each room and call for heat from many/any locations. this assumes that the TRVs do their job and do it well.



what I'd really like a wireless sensor t-stat .. anyone know of any? my lacross thermometers are wireless and cheap no reason a t-stat couldnt be. zigbee? my TI wireless temp sensors end up being a waste of money, they don't have any useful range.

crash2009

wireless thermostat?

Google wireless "averaging" thermostat

I thought about installing TRV's everywhere also.  Some how I talked myself out of it. 

FJL

Remote Sensor T-Stat

White Rogers makes a t-stat with a wireless sensor that you can actually move from one room to another. Here is a link to it. If you google the model number you should be able to find the WR website with manuals and other info.



Here is the link: http://www.acsuperstore.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=WHITER33&Category_Code=White_Rodgers_Thermostats&Store_Code=1

jpf321

remote RF sensor average only

Thanks FJL .. however, that remote sensor t-stat only allows averaging (or weighted averaging) with the local base .. here's the manual: http://www.emersonclimate.com/Documents/White-Rodgers/0037-6841.pdf



I'd prefer to have a dumb base with temp only from remote sensor and no averaging. I suppose I could motivate and run wire, it's not a difficult pull.

FJL

Dang!

That is not good for me either. 



BTW, have you or anyone else used a Danfoss TRV or other TRV with a remote sensor?  Nearly all of my rads are in drafty areas.  Do they work just as well with a remote sensor?  Plus, are there any TRVs with a wireless remote sensor?

jpf321

yes and no

yes i believe the TRVs with remote sensor work just as well.



no they do not make wireless remote sensors since the "wire" is a liquid filled capillary tube. Macon's catalog says that standard length is 6'6" but longer lengths are available "consult factory". Standard 6'6" remote sensor is item number: MTWZ



TRV sensor mounting location is important, as you are aware. try not to place on exterior walls. Macon also makes a remote sensor + remote dial combination so you don't have to have access to the rad area to make dial adjustments. (#ENTLZ B56000)

FJL

Danfoss vs Macon

I guess you are partial to Macon?  I currently have two Danfoss on rads in my living room, but not the kind with a remote sensor.  I'd like to install a TRV with remote sensor in my child's bedroom, so a wall mounted dial would be ideal for her.  I guess I'd have to go with a Macon for that room.  I think a six foot wire would allow me to mount the dial on an interior wall.

jpf321

macon

is fairly local and I like local. additionally I have their printed catalog.but most importantly they were graciously gifted to me since the person knew I would put them to interesting use

FJL

Macon

Now I remember why I have Danfoss.  They cost waaay less.  The price tag I saw for a Macon was way too high for  my liking.

jpf321

the only prices I can find ..

for theseMacon TRVs is at StateSupply .. and if you are working from those prices .. I don't blame you for the sticker shock .. but it also looks like StateSupply has high prices on everything compared to say, PexSupply.com or SimplyPlumbing.com



and don't forget the macon's come with Actuator, Valve, Vacuum Breaker and the actual valve ..



For danfoss you need to purchase:

  http://www.pexsupply.com/Danfoss-013G8250-Direct-Mount-Operator-5558000-p

  http://www.pexsupply.com/Danfoss-013G0140-Thermostatic-Rad-Valve-w-Vac-Breaker-1-Pipe-Steam-5551000-p

AND

  http://www.pexsupply.com/Danfoss-013L8011-1-Pipe-Steam-Air-Vent



For example: Gorton #2

   http://www.statesupply.com/gorton-vent-gx1035

   http://www.pexsupply.com/Gorton-G2-Gorton-No-2-Straight-Air-Eliminator-3524000-p



Hoffman1A:

  http://www.pexsupply.com/Hoffman-401422-1A-1-8-Adjustable-Angle-Steam-Radiator-Air-Valve-3516000-p

  http://www.simplyplumbing.com/hoffmanspecial-1a.html

  http://www.statesupply.com/hoffman-vent-hk1005



Pressuretrol Honeywell 0.5-9 .0psi break on rise:

   http://www.statesupply.com/honeywell-electric-pressuretrol-hn1442

   http://www.simplyplumbing.com/honeywell-pa404a1033.html

   http://www.pexsupply.com/Honeywell-PA404A1033-Pressuretrol-1741000-p



MM#67:

  http://www.statesupply.com/mcdonnell-miller-electric-control-mh1067

  http://www.simplyplumbing.com/mcdonnellmil-149400.html

  http://www.pexsupply.com/Mcdonnell-Miller-67-Float-Type-Low-Water-Cut-off-Steam-1998000-p

haaljo

2 stats

"having a second (independent) t-stat on 3rd floor

which could also call for heat .. that would work right?"

I have 2 tstat's that can call for heat. Both are independent of boiler for power. The Honeywell Vision has batteries and the other is an old mercury.with a mechancial setback. Having 2 has been handyl for manual overide but that's about it for me.

But it will work at least with the way I have them set up.

Charlie from wmass

NEVER INSTALL A TRV IN THE ROOM WITH

THE THERMOSTAT. If you install trv's everywhere move the thermostat to the room that heats the poorest.I have seldom found a residential system that needed trv's on more than a few radiators. remember a trv never calls for heat just stops it coming.They are high limits. If trvs are used through out a whole building it is usually because the heat is turned on by outdoor temps not indoor. If the boiler is small enough this can be a very efficient system. Residential usually does not lend such a margin to be exploited. Even the closest to right size boiler is over sized and wil short cycle hen too much load is shed.

jpf321

a second t-stat

would be used to call for heat in different (cooler) part of the house.if the warm part of the house is still warm then those trv's are closed heat would only go to the cold part. I know trv's only limit hence the need for an additional t-stat.



I'm picturing it as a "send heat to cool zone system"...if third floor calls but first floor is at temp then trv's on first are closed and heat only goes to third. likewise the reverse. am I missing something fundamental that makes this theory flawed?



perhaps during a cycle started from the third floor the first floor calls...that's ok too..trv's on first must now be open and heat will be distributed properly..for a time there may be heat to both first and third but then trv's from earlier start will begin to close...



you may well be right but this all sounds plausible and I think I'll try it.

Kevin_in_Denver_2

Thermostat designed for Steam Heat

Jpf,



I had a WR wireless thermostat, but wound up replacing it with a Honeywell Vision Pro 8000. It was the best stat I could find with a "steam" setting, which means one cycle per hour. That one feature fixed more of my heating problems than any other single item.



It's an apartment building, and I actually employ a little bit of setback (4 deg F max) during midweek days and in the middle of the night.



Having thermostats everywhere is NOT the way to get your building to heat evenly.

David Nadle

Too many cooks

The potential problem with having many controls is instability. Instability can lead to oscillation. Imagine a scenario where each "zone" calls for heat in a rolling cycle, with at least one thermostat calling for heat at any time. The boiler runs, or wants to run, continuously, and the TRVs are all stuck shut. I can't say that's what will happen, but it's certainly possible.

 

There are sources of instability in the scheme you described. Multiple thermostats and TRVs may not agree precisely on what 70 degrees is. We're warned not to put a TRV in the room with the thermostat for a good reason. Adding thermostats and TRVs everywhere could compound the issue.   

jpf321

yep ..

i'm aware of the potential pitfalls of the design.. but i'm also excited about any possible upsides .. it will require some careful calibration and tweaking for sure. i have a spare t-stat and i have a few more trv's .. all it will cost me is a roll of t-stat wire and some time spent on the wire pull .. then I can put my curiosity to rest :-)



of course I will report with details and i'll be prepared for the "we told you so".



thanks

mart

I have a steam system with zigbee type radios, every room zoned, working.

I am a mechanical engineer, I have a system ready if you want, radio and electronic valve on every radiator vent, and control of the boiler via radio as well. A computer keeps track of everything, and switches on the boiler only when an adjustable amount of rooms are below there set point. At the moment there are 8 set points per radiator per day.



I have some spare radio boards and parts to sell if you are interested. I see you bought the TI radios so you must like playing!. Now you can have an internet link to you home heating as well!



Martin

jpf321

thanks.

look for an email from me in the next day or so. glad to see someone else with the bug. can you describe at all the economy of the system in terms of consumption? how much radiation you have installed? what your boiler is rated for? what your cycles are like? what a 30 hdd looks like? how tight your home is? I'm sure many folks here would be interested.

mart

electric TRV+ ?

I only have 8 radiators.



A new 125000BTU boiler I put in as the old one rusted through on week end I was away.



I dont know about savings yet, but comfort! downstairs cool at night 60- 63, bedrooms warm at night 72 , bathroom 65. Close all valves except bathroom for instant (ok 5 min) heat for the kids bath.



I can control the minimum boiler on and off time how many rooms are cold before I switch on the boiler, etc, I still have to write the logging part of the program to see what happening. I made one mistake where I was cycling the boiler, on off every 2 minutes but is was very interesting, water was at boiling and rooms stayed at the set points to the degree for hours!

jpf321

where are you located martin?

anywhere near nyc?

mart

continue

about 50 min away in NJ.

Have you sent me a private message?

jpf321

not yet

sitting in the car waiting on my elves while they shop.

mart

hi

I sent you one if you can look it up