# Wireless transmitters / end switch to boiler?



## dclark (Dec 12, 2010)

Hey all

Need some suggestions..

I have a customers house with radiant heating that needs / wants upgrading.

System is:
1 Atmospheric boiler
Indirect tank
Indoor pool water heated (exchanger)
Air handler coil (HRV for pool)
Tekmar 4 way mix (rusted in position)
Outdoor reset
Polytherm pipe & manifolds

1 manifold in boiler room
3 remote manifolds

Each remote manifold has a few loops (actuators) that are controlled by thermostats, and the rest of the loops are wild (on outdoor reset).
The only control that the thermostats have, is to turn the heat down (OFF) to the controlled area. Otherwise, the heat of the entire house is controlled only by the reset (outdoor temp).

The homeowner would like more control, and lower gas bills ($900 - 1400/ month in the cold ones).
Did I mention that the house was about 9000+ square feet with 1- - 20 foot ceilings? He does not heat his pool.

Anyways, the issue i have is.. there are currently no wires (24v or otherwise) leading from the remote manifolds to the mechanical room, and no real way of running the wires (2 floors above), short of running them outside the house.
I'd need 3 end switch (call for heat) signals from the manifolds to get back to the mech room.
I'm looking for a wireless solution.

The plan is, control all areas/loops with additional actuators, new mod con boiler, nice payday for the company I work for, and a happy customer.

Anyone know of a wireless solution short of the $1000+ each honeywell transmitters? I don't need the 1.6 kilometer range that these ones have 
I need 3 transmitters (preferably 24v input) that can send a signal through the house (100 ft max), and one receiver that can close a contact.
The customer has an issue with @ $4K (+ our markup) for that part of the system.

Thanks for any ideas or suggestions!

Don .


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## Scott K (Oct 12, 2008)

I thought I recalled reading somewhere that Honeywell has some wireless thermostats or something along those lines (but haven't checked into it since). 

Maybe worth looking into. Also, you may want to bark up the tree of contacting your hydronic department at your local wholesaler as well. Tekmar may have a solution as well and it may be worth contacting Todd Davis.


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## dclark (Dec 12, 2010)

Hey Scott,

Thanks for the reply.

I've installed the Honeywell wireless tstats in furnace, hwh, and heat pump applications.
The stats are not my problem. I'll be using the existing stats to activate the actuators and additional actuators (just group them together).

My problem is that i need an additional signal from the manifold (end switch-es) to the mechanical room.

I'll contact tekmar, good idea, and thanks again.

Don.


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## Scott K (Oct 12, 2008)

Now you DID say that the 4 way mixing valve (WOW, someone who actually used a 4 way mixing valve and did things properly, these days all I've seen are 3 way mixing valves on atomspherics) is frozen which in theory means the individual in question is not getting THAT much control as to temps sent to the floors which could cause overheating of various living spaces. 

I think a good mod-con boiler that is tuned to the space with proper strategies could alleviate a lot of the issues with potential overheating of space and the lack of control. A good mod-con will also make a sizeable dent in the gas bill - I'd think in the range of 30%-ish, assuming it is set up properly. 

I'd be interested in hearing about the different zones that each manifold heats. I'm thinking about heat loss versus floor surfaces versus windows/ceiling heights. If the floor surfaces off of one manifold are all hardwood (or there abouts) and another manifold feeds primarily carpetted areas, you have the rationale to break up the heat mains off of different pumps or have 3 way mixing valves to mix them down even further (depends on the boiler and the controller you're working with though). You also said there were some high ceilings - perhaps another manifold that might need it's own temperature, depending on tube spacing as well. 

Also, 9000 sq. feet - that's a decent sized house. At about 15,000-20,000 BTUH's rough heat loss per 1000 sq. feet you're looking at around 135,000-180,000 BTUH heat loss give or take (extremely rough heat loss) for the entire structure on design day for Vancouver. 

What boiler did you have in mind as replacement?


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## dclark (Dec 12, 2010)

Hey,

The manifolds are mixed, and big.
2 manifolds located on the lowest level each feel up and down, 1st and 2nd floors.
The basement has 9 foot ceilings, the main floor has mixed, from 9 or 10 to about 20.
Floor coverings in the basement are tile and carpet.

The top floor is mainly bedrooms, carpeted, master suite + 1 bed off of one manifold, and 3 beds off of the other.
Main floor is mixed.

So.. multiple temps will be out.

Heat loss is likely 160ish, + indoor pool and fan coil.
I'll do the heat loss and pool calcs once we get to the design stage.

The options I'll be giving him will be something like

1. 2x IBC150
2. 1x Buderus GB162

Better turndown and lower opperating costs with the IBC option, but substantially more initial cost, plus the venting headache.
A single vent could run through the existing 8 inch bvent, but with 2, i'd need to remove it.

I"m not going to get too excited about this one until i find a wireless solution, or the owner agrees to a little exposed conduit on the outside of his house. The wire could be a deal breaker. No attic. but the last desperate option might be exposed on the roof, and down the vent chase, which would leave one manifold from the basement without a signal back to the boiler. .. 

He may end up going with an atmospheric and new mixing or injection.

Should end up an interesting job, but won't happen until spring when they head away for vacation.


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## Scott K (Oct 12, 2008)

If you're going up the chimney with the two IBC 15-150's, depending on the length, you might be able to get away with the 2" vent option on each boiler if you're taking inside air or tie into an existing vent duct and split off to each boiler (this is without seeing each). An IBC 45-225 might work well in this application as well, depending on how big/when the pool is being used. 

Without seeing it's difficult to ascertain how much of a big deal running wires are. Have you tried talking to any of the local control companies as well (Myers, Pacific, Regal, etc.)? They might have solutions as well. I think you're gonna have to break out the pricing versus payback for this customer in a well written document.


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