More TRV's and some observations

ChrisJ

So,

After adding a Honeywell Prestige and 3 wireless sensors over the summer I decided I wanted to add 3 more TRV's to the system, this time on the first floor.

Before the first floor was basically the thermostat area, but not anymore so it gave me more options. While the thermostat is basically centered on the first floor, the 3 wireless sensors are in the 3 bedrooms on the second floor.

The 4 locations are averaged.

I'm adding TRVs to both kitchen radiators at 30sqft each and the one 60sqft livingroom radiator.

This will help correct special scenarios such as when the wife runs the oven all day and causes the second floor to get colder than usual. At least, this is the plan.

Now before getting the TRVs I did some testing so I'd know what could happen, worse case. However, before the est my plans were only to use two TRVs on the first floor and I later decided in 3.

I put tape on one 30sqft vent, and the 60sqft livingroom vent and closed both upstairs TRVs and ran the system. I allowed it to heat for 10 minutes, meaning it started being timed once the main vents closed. After 10 minutes of "heating" all of the radiator vents in use were hot and my pressure hit 12 inches WC and the Ecosteam shut the system down for 10 minutes. I later lowered this a tad to 10 inches for no real reason.

I found it interesting that heating only 203sqft with a boiler rated for 325 sqft I still didn't build any pressure until vents started closing. Right now, I'm assuming this is because of how fast I have the radiators vented.


Makes me think of anyone is building any significant pressure with cold vents, they need to speed them up.


Anyway, I'll be adding the 5th TRV sometime this week. Like a dope I tried installing them while really sick and I dropped one and damaged the starting thread on it. Fixed it today with a die so it's ready to go, again.

Either way, if, by some mircacle all of them were closed, even on the first and second floor (unlikely) the Ecosteam will still step in and shut it down at 10 inches and give those few radiators time to dissipate some heat. Being I'll have TRVs on 219 out of 392sqft.

My original two are Danfoss brand and the 3 new ones are Macom. The Macom's appear to come with VentRite brand vents so I'm actually going to try them out. The ones Danfoss sells I didn't even consider.

ChrisJ

@Fred
@Gordy
@Jamie Hall

No comments? I'm surprised!

hvacfreak2

Curious , what didn't you like about the Danfoss units ?

ChrisJ

hvacfreak2 said:

Curious , what didn't you like about the Danfoss units ?

The only real thing I dislike about my 2, and it's minor, is the numbers on the control have claimed temperatures in the book and mine are not even remotely close. The published temp numbers for my use are meaningless, but I'd be pissed if I installed a few hundred in apartments and set them to those temps to find out all were completely wrong.


That said, I would've went with Danfoss again but figured I'd try out Macom this time around. Macom's temp numbers match their literature tho.

I've got zero real complaints about the Danfoss ones and they've been in the two bedrooms since 2012 or 2013 I think.

The Danfoss control snaps onto the body while Macom's tightens on via a large nut. Danfoss's vacuum breaker is internal and in the bottom while Macom's is more steam punk and mounted where it can be seen.

Overall I cannot say if one is better than the other, at least not yet. The Macom has a more robust and commercial feel while the Danfoss has a more refined and residential feel. If that makes any sense?

Fred

Actually no real comment from me. If the TRV serves a purpose and doesn't cause any short cycling, I say Go for it.

hvacfreak2

I went with Danfoss thinking that if someone makes a reasonably priced quality electronic actuator they will make it to fit Danfoss valves. I liked the look of the Macom though.

Danny Scully

It’s macon isn’t it?

Gordy

No comment let's see how it works. Should be fine.

ChrisJ

> @Danny Scully said:
> It’s macon isn’t it?

Yes I think you're right. Macom sells RF parts I think.

I worked in that world too long I guess

JUGHNE

FWIW, the only TRV's I have to deal with were in schools.
The plastic thermostat head gets twisted or just broke off.
Probably not an issue in private homes, (unless one has 2-3 boys).

So in one case the head was broken and the stem was leaking steam. I installed a standard valve with very undersized orifice in the union.......was a very oversized radiator also. No callback yet. (2 pipe of course)

EBEBRATT-Ed

I believe if you check out the Macon/Tunstall site that you can buy electric and electronic actuators for their valves....same valves different actuators.

Although, I am not positive about their 1 pipe valves, I know their available for two pipe

acwagner

ChrisJ said:

I found it interesting that heating only 203sqft with a boiler rated for 325 sqft I still didn't build any pressure until vents started closing. Right now, I'm assuming this is because of how fast I have the radiators vented.

I think another contributing factor is the rate a radiator condenses steam varies over time. Attached is a rough curve showing that when the radiator is first warming up it can condense up to 3.5 times the amount compared to when the radiator reaches steady state. I pulled it from a trade article from the 1920's. Basically, radiators have a high capacity at first when warming up the mass of cast iron and easily met the supply from your boiler, even with only 62% of your radiators in service. Once they started hitting equilibrium, the vents close, the rate decreases and supply outpaces demand, and the pressure starts going up. Basically, the graph shows the "pick-up factor" concept. Bigger boiler can power thru the curve faster and get everything fully heated faster....and then start short cycling.

I don't know why they took so few data points in this study...seriously, every 10 minutes for a 40 minute test?