On Sunday, September 28, 2014 11:59:13 AM UTC-4, Ed Pawlowski wrote:
On 9/28/2014 10:28 AM, nestork wrote:

Mike:



Indoor/Outdoor reset controls are available for both hydronic and steam

heating boilers.



But I think you're missing one important point. Apartment blocks are

built different than houses. Houses have lumber exterior and interior

walls that have very little thermal mass,



Really??? How about the hundreds of thousands of homes built from other

materials? Stone, block, ICFs SIPS. brick. adobe, concrete, etc.







It's the thermal inertia of your concrete block walls that would prevent

any boiler or boiler control from being able to follow those 24 hour

temperature guidelines you quoted.



Why? It only matters getting the temperature up at the required time,

lag to the lower is not a problem, not does it have to go that low. You

will have to anticipate the time for increase and the boiler will have

to come on before the required time to reach the daily minimum for

daytime.









You can put in an indoor/outdoor

reset control, but it certainly wouldn't be able to modulate the

temperature in your building on a 24 hour basis like that. So, in that

regard, you'd probably be best off to install an indoor/outdoor reset

control, set it to provide a comfortable temperature inside your

building and leave it at that. Trying to change the termpature of all

that concrete every 12 hours or so is simply not going to happen.



It does not have to reach the 55 degree at night, that is a minimum. He

can set it to whatever works and makes sense. I'd think that 62 or 64

minimum would be better in many respects. Happy tenants and easier to

maintain the swings.


I was waiting for someone to bring up the ridiculous 55 temp. That might
be acceptable on an emergency basis, for a few days. But you'd have to be
a slum lord to deliberately target 55F as an acceptable temp, just because
the govt says it's as low as you can go and still not get fined, etc.
From a practical standpoint, if you have it at 68F at 10PM, for typical
building, it's not going to get to 55F, unless it's some place exceptionally
cold or purely insulated, etc.

And I think Mike is conflating two different things. One is just setting
back the temp at night. I guess you could screw with it more, basing it
on outside temps, if you're really going to go to those guidelines. But IDK
anyone that wants to live that way and I wouldn't do it to tenants . I'd
have a min temp for day and a min setback temp at night that didn't depend on
the outside temp. So, all you need is a setback thermostat that is secure
and tenants can't screw with. How you do that, IDK. Plenty of tenants have
enough smarts to figure out how to bypass stuff.

The main purpose of the outdoor temp reset, AFAIK, is to moderate the temps
that the boiler runs at. At least that's how it works with hot water. If
it's 45F out, you don't need to run the boiler water as hot as you do if it's
10F out. That lets the boiler run a little more efficient. AFAIK, you can
still set the individual thermostats to whatever you want. Also, IDK how
this concept works with steam, because you do need to make steam, not just
heat water. But apparently the reset controls do exist for steam.