Non-Electric Zone Valves & Thermostats

Unknown

Any of you Wallaies used these neat little non-electric devices before? If so, what do you think of the KISS technology? They're sort of like a TEV for cooling equipment. Also, where can I find them?

Heres the article. It's near the bottom as a Sidebar
The Virtues of Constant Circulation; http://www.supplyht.com/CDA/ArticleInformation/coverstory/BNPCoverStoryItem/0,5331,109239,00.html

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Unknown

Dennis Bellanti & Constant Circulation.

I recently read a Sidebar editorial: "The Virtues of Continuous Circulation" in Supply House Times by Dennis Bellanti. What's his "correct" e.mail anyway? dennis.bellanti@ferguson.com keeps bouncing back.

I'm interested in trying these non electric zone valves and thermostats for a job I'm doing. I'll be useing an MZ condensing boiler. I've got two zones on two floors and an indirect. Not sure if I'm going to use OA reset or not. Two loops. All copper Fin/tube convectors "Cheap Wet Heat"

My heat loss estimate comes in at a whopping 52,000 BTU'S and the MZ packs 94,000. Thats ok, I''ll use all of that to make and maintain DHW in my HTP SuperStor right?

I know, I know, I probably won't see too much condensing with BB fin/tube convectors. I would like to build the perfect heating system. This is not that system. However, I'd like to make this BB system as efficent as possible.

Seeing how I'm fixin to run it constant circulation on the main floor,

1) You think that the use of these non electric T stats and valve combination would improve the system lag and overshoot on this type of setup?

2) Will it be nessisary to reset system fluid temp? Why? Won't throttling down on the flow through the zone reduce the output?

3) Wondering if I should be using a pressure activated bypass on something like this?

Gary Wallace
Wallace Radiant Design


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Mike T., Swampeast MO

Remember that when installing them on a loop system that you have to pipe in a bypass around each baseboard or room. If you don't those B/Bs further down the loop will be starved as the valve in the first space is satisfied. Installing them inside the B/B enclosure will vary in difficulty with the style of the enclosure. Pay particularly attention to the suggested placement of the actuator's sensing element. A remote sensing model may well be best. If impossible to install inside the B/B enclosure itself models with both remote sensing and setting are available. If using such however, PLEASE leave the valves in ACCESSIBLE locations!

1) TRVs (particularly combined with constant circulation) are VERY good at reducing temperature fluctuation. With a B/B system expansion and contraction noises should be greatly--if not totally--reduced.

2) Reset will STILL make a lot of sense. TRVs can ONLY regulate flow velocity. While they may seem to regulate the temperature of the output device such is only an "artifact" of regulating the velocity. The combination of high temperature and low flow can adversely affect performance (see sketch). MUCH better to reduce the supply temperature with falling demand so that flow remains relatively constant.

3) If you have set up the system (or a loop) where it is possible that all (or nearly all) flow will be stopped during periods of low demands then you must make some provision to relieve the circulator--a differential pressure bypass valve is commonly used. Remember that non-electric valves are proportional and mechanical. There is no practical way of communicating a no-flow condition in order to shut down the circulator.

As to brand: TRVs as a class seem to be highly reliable. I believe all use some form of valve packing around the actuating device and that such is likely the first? only? thing to go bad. Some (maybe all) can have this packing replaced without draining the system--such seems a very nice feature.

Steamhead

Here's one of mine, Gary

Honeywell/Braukmann TRV on a cast-iron radiator. This is a converted 2-pipe gravity system without (for now) reset. If you're using a series-loop setup you must install bypasses where TRVs are used. It might make more sense to install Monoflo tees on the main loops, then your TRV bypasses won't affect flow in the main loops so much.

I find TRVs to be most useful in rooms that are routinely kept cooler than the rest of the house (or zone), such as bedrooms and some kitchens. There's not much point in putting them in the area where the thermostat (or indoor sensor with reset) is, since doing so might cause the rest of the house to overheat. I would also avoid putting them in bathrooms, since there is so much moisture in them which can cause mold if the room is not dried out quickly.

I also like zoning the house based on how the rooms are used. One zone for the main living area, another for first-floor bedrooms, a third for second-floor bedrooms and so on. This way you can control each zone individually, and use TRVs on some radiators for even closer control.

If you have a rather low heat load, you can run a lower water temperature by using larger heat emitters. This will help keep the MZ in condensing range.

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Jack, CVMS

Non-electric thermostats

Did a ten-room addition to a local hotel seven years ago using continuous circulation, diverter tees, and TRV's in each room. Works great, no maintenace to date. Now I have to convince them of the advantages to outdoor reset (especially effective when temperatures range from -50°F in winter to 85°F in summer (and little old ladies from Florida expect heat in the summer).

Same with an addition to a church - TRV's control maximum temperature in three zones each upstairs and downstairs, and maintain nice, uniform temperatures.

bluenose_16

sizes

Do TRV's come in different sizes? I was thinking about put one on a rad which has a 1.25" supply. Would you size it according to the line size?

Mike T., Swampeast MO

Danfoss makes them up to 1¼". Not certain about other mfgrs. There is a big price jump over the 1" valves and you probably don't need the additional flow BUT they generally make direct replacement for the existing valve and the cost (and aggravation) of re-piping to a smaller size might be greater than the increased cost.

ToothFairy

Dampers

I have one room directly above my forced air furnace that is extremely warm. I would like to regulate the heating of this room. I have tried closing the register but that does not seem to completely solve the problem. I think that maybe a damper placed in the ductwork directly exiting the furnace would solve the problem .

We live in an old house(circa 1861). The furnace is new about eight years old but the ductwork is much older--rectangular in shape. I know that circular duct work is more conducive to installing a damper.

What would you suggest for this problem and where could I find the supplies to complete this project?

Thanks for your time.

Sincerely

J.D. Mayfield