Hi,
First post here. I have learned a lot by reading this forum over the last couple months. I am in the planning stages for new construction 5000+ sq ft house in NJ and plan on using warmboard throughout with a mod/con boiler, indirect DHW and 7 zones. I have not seen anything as to how well this type of system would work with a home automation system - something like the HAI Omnipro (or similar if you have any suggestions). Can an outdoor reset work with these? What about Tekmar controls?
thanks in advance, and I am sure I will have many more questions.

Jeff

Forget the controls - design the house envelope first to minimize the heat losses and reduce the thermal load variations in the zones and you'll get much more bang for the buck.

That being said, the system you are thinking of is a "medium mass" floor heat system and will respond OK with modulating controls. A "home automation system" is simply a programmed digital control system and it will work as well as the guy programming it, and the hydronic system and components it's wired to. The key is having the guy programming the system have a very good knowledge level of the heating system operation, thermodynamic response of the house and a clear understanding of what YOU want to achive out of the system. A rare breed. Most home automation contractors/suppliers know the control system well, but seldom understand the heating and home comfort systems controls, and sequence of operation to be able to set up a hydronic heating system properly

thanks for the reply. I am not skimping with the house design... 2x6 exterior walls with icynene(or similar)inside them and between floors, low e glass, HRV, etc. I am doing this once, so I am trying to do it right.

I had not thought about the details of setting it up. I figured that I would get a well engineered radiant system and then use the omnipro to centrally manage the zones rather than running all over the house to do it. I thought It would be similar to computerized thermostats in each room, but easier to manage and tweak. I figured I would be tweaking it to work with how we live in the house after we move in, I guess I am oversimplifying it.

Should the controller installer be consulting with the radiant designer/installer? Any other advice? I am going to be interivewing GC's soon and want to make sure they can do what I want. I will of course insist that a good heat load calc be done after the plans are completely spec'd out.

thanks

Jeff

I recently saw something from tekmar that showed an Ethernet interface into their tekmarNet4 (tN4)controls. I don't know if it would integrate into the Omnipro system, but I suspect that it can get you to the type of centralized control you're talking about.

I can't find that interface right now on the tekmar web site--either I didn't look hard enough, or it's a new thing that I saw in an ad that isn't in the tN4 literature on the web site. You might want to give them a call and talk to them about it. (If so, I'm sure most of us would love to hear about what you find out . )

Tekmar spent a small fortune promoting Tek Net 4, got everyone all jazzed up about it, and then delayed it's release. They apprarently had some patent issues to iron out.

Yeah, but are the 2x6's in the exterior wall touching the outer skin as well as the interior drywall? If so, those thermal bridges on 16" centres will de-rate your wall insulation by up to 20% or more. Ditto for the thermal bridging at the floor plate edge and wall to ceiling top plate joint. "Low-e windows" are not necessarily "high performance" and you need to check the performance specs as well as police up the window frame detail and sealing thereof. High performance to me is at least triple glazing or Heat Mirror, with solar gain control on the exterior via awnings, shades, overhangs etc.

Yes, the home automation guy MUST talk to the radiant designer/installer so they can make sure that the system controls are compatible and set properly. Many times the boiler has on-board controls that do thier own thing while someone else screws up the room by room controls so they don't follow the boiler sequence.

After the first heat load calculation, sit down with the heating system designer and the GC and see where the big heat losses are and see what can be done to minimize them before sizing systems, and make sure the heat loss calculations are as accurate as possible and not just based on a canned program with assumptions built into the data. The cost/benefit exercise will be worth it.

G.,
I never considered the 2x6's being a thermal bridge. How can I avoid that? (newbie here ).
I agree with your definition of high performance and I am incorporating solar gain control into my design and I had planned on triple pane glass in a high performance window. My fault for not listing that.
I like your idea of getting the HLC done and then seeing how to improve the design to reduce losses. I will definitely do that.
Keep the advice coming!!

For more information on high performance, low energy/high comfort home building, go here:

www.healthyheating.com/home-heating-system-design.htm

Scroll down through some of the articles on building envelopes and whole house system design. Check some of the resouces in the references section of the articles for reducing thermal bridges at wood frame construction. Also check out some of the information at www.buildingscience.com for some more stuff.

This message has been edited. Last edited by: G.McDonell,

Tekmar is releasing two gateways before too much longer, and one of them is supposedly geared specifically for integrating with home automation systems, just to answer the original question.

the other..surprisingly!.. sounds like it will run through a mac OSX machine to web serve itself. I guess it was easier with Unix than windows?? that's a first... someone liking the macs I predict an upshot in mac mini sales soon...

G. - thanks for the links - Lots of reading to do tonight.

Rob - thanks for the info. I am trying to start construction in late spring or early summer. What are the chances I can implement these into my house? Like Solarpower, I cannot find anything on their site about it. Do you have any other details.

Has anyone actually installed radiant with home automation or have it? Any suggestions or advice as what I should be looking for or avoiding would be appreciated.

Jeff

well, all the home automation systems I've personally looked at (which isn't many) are geared for air systems. However, I see no reason why they could not handle a relatively fast acting radiant like Warmboard.. basic honeywell rounds do both adequately in most cases, after all.


What little info is available now is here:

http://tekmarcontrols.com/literature.html

click the teknet 4 brochure, scroll down forever.

thanks Rob,

I found the info in the brochure - it is the TN4 gateway 482 that has an RS232 interface. I am going to call them and see about release dates. It looks like that is exactly what I need.

Quick question on thermal breaks - if I have 2" EPS insulation (similar to ICF forms) attached outside the sheathing, and put siding and stone outside that, would that provide a thermal break, or does the thermal break need to be between the studs and the sheathing to be effective?

thanks

The thermal break has to be between your heat loss and your heat gain. As long as you don't have a continuous low-R route from hot to cold, it doesn't matter if the insulation is inside or outside the sheathing, you're still covering the "bridge". However, I have no idea what impact that positioning has on other aspects of the building.. I'd check around on Buildingscience.com, I bet they have a discussion of it somewhere!

I want to mention that I have radient in floor heating with an Omni Pro system. No issues at all. The thermostats will control anything you desire. A note to keep in mind though is that the thermostats and zone controllers have their own 24 volt systems and you need to use isolation transformers to switch the zone relays. Small 24 volt ransformers as supplied by a heating contractor will work. I had a friend in the business help me with a drawing of what I needed to do and it works fine. A nice thing about an Omni or other controllers is that they will work at lower temps. For instance I turn my garage in floor heat on at 40 degrees. The system monitors a temp sensor in the garage and takes care of it for me. I have yet found a thermostat that goes that low.

oakguy

I believe most of the Totaline thermostat series goes down to 35*.