Joined on November 14, 2009
Last Post on August 3, 2014
@ March 1, 2014 8:17 AM in Pickup factor. Help me understandThere's something useful in every steam heating related publication from the University of Illinois Engineering Experiment Station. Their in-depth studies of the effects of radiator enclosures are particularly fascinating.
I wonder when the last time a scientific study was conducted on anything related to steam heating.
@ February 16, 2014 8:15 AM in Kickstart THIS!That's great, ChrisJ, thanks. I'll put you on the list of potential beta testers.
@ February 16, 2014 7:18 AM in Kickstart THIS!It could, but there's a much wider selection of ODR systems out there for hot water, so it's probably not worthwhile to try to compete in that market space.
@ February 15, 2014 8:16 PM in Kickstart THIS!The outdoor reset controls currently available for steam are targeted towards commercial and multi-family buildings rather than the residential market. They're a bit pricey for the individual homeowner.
In principle, there's no reason that outdoor reset shouldn't work on smaller systems. And in practice, the outdoor reset control on my residential system has been operating successfully for a couple of years now (even before the Midco burner).
@ February 15, 2014 7:37 PM in Kickstart THIS!an affordable outdoor reset control for single-family residential steam?
It's coming. Anyone interested?
@ February 14, 2014 3:14 PM in New Thermostat really improved my steam indoor comfort levelyour data for a couple of days at 2 CPH and another couple at 1 CPH, see which works best for you. Let us know how it works out.
@ February 14, 2014 2:04 PM in New Thermostat really improved my steam indoor comfort levelYes, 67 degrees. The sensors read a bit lower because, in addition to being in different rooms, they're mounted 24-36" below the thermostat.
The manual doesn't say you can set function 240 to 2, but it can be done. A number of people here have seen good results going from 1 to 2 CPH.
@ February 14, 2014 12:51 PM in New Thermostat really improved my steam indoor comfort levelWhat do you have the "First stage heat cycle rate" function 240 (aka CPH) set at?
I recently started running my outdoor reset controls off of the same model thermostat instead of individual temperature sensors, just to see how the two compared. The temperature swings aren't quite as tight as running from sensors, but there hasn't been a perceptible change in comfort level. I have function 240 set at 2. Here's a chart from last weekend.
@ February 13, 2014 10:26 PM in Meet The CozyHi Marshall,
Do any of the steam boilers on your test systems use any sort of outdoor reset control like a Tekmar 269 or a Heat-Timer? Overshooting setpoint is a pretty common problem if they're just controlled by a thermostat.
@ February 13, 2014 7:57 PM in Time Delay Switch InquiryDon't use a primary safety limit control (the vaporstat) as any part of the time-delay control scheme. Control limits and safety limits must be kept separate. If something happens and your insurer finds out you modified a primary safety limit device they could deny your claim.
Besides, the Dwyer switch is inexpensive enough. Just saw a new 1823-20 on eBay for $15.
@ February 13, 2014 6:08 PM in Time Delay Switch InquiryHi Clank,
About four years ago I developed a time-delay relay pressure cut-out and installed it on my system. The thinking was that if the boiler cuts out on pressure, then the system is (or should be) filled with steam. And if the system is filled with steam, then the latent heat should be left to do its job, and the burner shouldn't re-fire until then. After some experimenting I found that a 20-minute "off" period worked pretty well on my system.
Here's a link to the thread with more discussion and wiring diagrams. If possible, I recommend you go with the low voltage solution. If your ignition control doesn't provide secondary 24 vac power like the Honeywell R7184, you'll need to use an external 24 vac adapter to power the pressure & relay circuit.
In the original installation I used a vaporstat, but you don't need to go to that expense. Dwyer Instruments makes a low differential pressure switch that works quite well and can usually be found on eBay for a good price. The one I use now is a Model 1823-20 with an adjustable pressure trip point between 3" and 22" w.c. (1.7 to 12.7 ounces). If your system runs at a higher pressure, check the Dwyer catalog here to find a model that fits your pressure range.
@ February 12, 2014 2:39 PM in Kenawee Smokeless Firebox No. 111Gross weight is the weight of the coal plus the weight of the container (in this case, probably a truck) that the coal is being weighed in.
Tare weight is the empty weight of the container (truck).
Net weight is the amount of coal delivered. Net = Gross - Tare.
On your receipt, the weight of the coal + truck (gross) is 34,200 lbs, the weight of the truck (tare) is 14,100 lbs, and the weight of coal (net) is 34,200 - 14,100 = 20,100 lbs.
@ February 10, 2014 8:13 PM in Meet The CozyHi Marshall,
The before and after charts of room temperature regulation are pretty impressive, and I'm sure this thing works as well as is claimed. What I'm not clear on, and Ban touched on earlier, is the impact to the performance of the boiler once a complement of Cozies is installed. I'm sure you guys have a lot more study data than you've published on either Kickstarter or your web site. I'd be interested to know:
1. Did you evaluate the steam systems before the Cozies were installed? Things like near boiler piping, main venting, boiler rating vs EDR of the connected load. Think "WWDD" - What Would Dan Do?
2. Did you/are you monitoring boiler factors such as run time and pressure, both before and after the Cozies were installed in the test buildings?
3. If all the Cozy's on a system are shut off, is the boiler prone to short-cycling?
4. What happens to the boiler firing rate/pattern when a Cozy is installed in in the apartment or dorm room that contains the common building thermostat?
5. How much power does the Cozy draw? Any fuel savings claimed would need to be offset by this.
@ February 8, 2014 11:19 AM in An Epic Tale: I hear the Trane a comin'!Yes that would be an interesting challenge, NBC. It would require a fair bit of study of the actual dynamics of the system under various conditions to come up with a control scheme. Unfortunately, I have only a 1-pipe system and don't have access to a vacuum system for study. Maybe it's time to move...
A heat-loss based outdoor reset algorithm such as the one I use in the EcoSteam controller, calculating how many btus need to be put into the system to maintain temperature, could potentially be one input to such a control. The vacuum part would be tricky. Since vacuum keeps the steam (and btus) coming after the burner is off, you'd also need to predict when to shut down the boiler(s) ahead of the heat loss algorithm's cutoff time. A "vacuum anticipator", if you will.
MDNLansing posted earlier in this thread about his experimental work on his own vacuum system control. I don't know if he's gotten as far as using a predictive algorithm, perhaps he'll comment.
@ February 7, 2014 6:45 PM in Crown boiler doesnt keep up with thermostatJamie, I assume you're talking about whether the boiler is cycling on pressure, but the boiler is going to shut off periodically regardless due to the CycleGard LWCO's "intermittent level test" feature.
@ February 3, 2014 4:18 PM in Burnham IN5 with Cycleguard LWCOMy CycleGuard was in service for less than a month before I ditched it in favor of a Safgard. The probe LWCO technology is fine, it's the intermittent boiler shutdown "feature" that's the problem. Plus, if you get a Safgard, you'll at least have a spare probe since the same probe is used for each model.
@ February 1, 2014 6:36 PM in An Epic Tale: I hear the Trane a comin'!That's great news, Colleen! I was beginning to think we'd have to run a Kickstarter project to raise funds to send one of our resident pros out to finish the install.
@ January 28, 2014 5:57 AM in The results are not conclusiveThanks for taking this on, Jamie. As with most things, the "common wisdom" regarding setbacks isn't as cut and dried as one would think.
What I find most interesting about your results is "a reasonably small setback (3 degrees) may make a small fuel savings, but the effect is not statistically significant." Put another way, this would seem to indicate that a small setback doesn't necessarily result in increased fuel usage, which is one of the often-stated reasons against setbacks.
@ January 24, 2014 3:16 PM in Forgot to put water in the pigtailIn the Honeywell documentation for the PA404 Pressuretrol and L408 Vaporstat, there's no mention of them being rated for direct contact with steam. The only temperature rating is for min and max ambient temperature. You'd think the specs would include min and max operating temperatures as well, but evidently not.
@ January 23, 2014 1:36 PM in Thermostats (Honeywell and EcoBee)Mine's an 1823-20 differential pressure switch, 3"-22" WC. I have it set to trip at 10" WC (about 6 oz). Repeatability is very good. You can find them pretty cheap on eBay.
@ January 23, 2014 12:38 PM in Thermostats (Honeywell and EcoBee)I had a modulating gas burner installed in the spring that adjusts the firing rate to maintain a pressure setpoint in the boiler, but the time-delay relay is still in place as a backup in case I ever need to run at a fixed firing rate.
When the vaporstat-plus-relay was in more active service, it worked exactly as I'd hoped. When the pressure increased after all the radiators were full of steam, the vaporstat would activate the relay, which interrupted the low-voltage thermostat signal for 20 minutes. This gave the steam in the rads a chance to condense, and more often than not the call for heat would be satisfied by the time the timer expired. If the timer expired and there was still a call for heat, the boiler would re-fire. Tracking pressure shutdowns over the course of two seasons, I figure the control saved 100 gallons of oil or more.
One change I made to the current setup is replacing the vaporstat with a much less expensive pressure switch from Dwyer. With the time-delay relay, I didn't need the cut-in capability of the vaporstat. And it's much easier to accurately adjust the trip point on the Dwyer.
@ January 19, 2014 12:01 PM in Nest ThermostatHBX Controls released a wireless remote temperature sensor late last year.
The resistance curves of the Honeywell remote sensor and the HBX are similar, only 3% different at 70 degrees, so the HBX sensor ought to work with a VisionPro. Downside: it's expensive.
High on my wish list is data logging and reporting. Despite its other flaws, that's one area where the Nest blows everybody else out of the water.