Discussion in 'Radiant Heating and Cooling' started by TJamesW, Dec 25, 2012.
Do it! and pictures please.
What control is it that monitors dew point so one can remove the sensible heat from the space without condensation. Need to come up with a control scenario where I am proiding sensible cooling using a radiant systems, and removing the latent heat with forced air. Any help would be greatly appreciated.
How did your controls work out using the Tekmar 406 to do radiant heating and cooling. I am trying to develop a controls scenario that monitors the floor temp for heating and cooling, monitor the air temp and dew point, in order to remove the latent heat and keep my RH down. Any advise would be greatly appreciated. Working on a radiant heating and cooling project now and the controls are frustrating me. I do not have the budget to have a controls company like eagle mountain price me out one.
My 406 project is a wip. I did take some pics, but ran out of day before I finished the thread. I'll try and re-do the thread tonight.
Teshj, from what you describe the 406 should work for you. One needs to watch one's piping. The plumbing needs to match the control's logic.
The Tekmar 406 control is limited to two stages of heat pump operation. I am in an instance where I need four stages of heat pump operation. I asked Tekmar if there was any epansion module available to accomodate the addtional two stages of heat pump. Their reply was negative.
I am going to try and find a way to use the 406 for my radiant heating and cooling on the load side, while maintaining my tank temperature as need be. The heat pumps should work off of a dual aquastat.
Any opinions out there?
You will get the most efficiency from your heat pumps by getting them to follow an outdoor reset curve, HBX has geo staging controls for as many heat pump stages as you need and one back up stage. The ECO-1000 can do up to 3 stages (incl back up) by itself, after that you need to add EXP-0100 expansion modules for every two stages you need. You could have the HBX running the heat pumps but getting the heating & cooling demands from the Tekmar 406.
HBX Control Systems Inc. - ECO-1000
Radiant Heating and Cooling
I've decided that the HBX Eco-1000 and the Tekmar 406 are a great combination. Now, I have to overcome the limitations of the 406 using zone valves and not circulators.
From what I have read, if I do my piping correctly, I will be able to produce the high/low temperature water for the fan coils and the medium temperature needed for the radiant floors.
I am getting a little concerned about the composition of the radiant floor. They want to use Warmboard and its too late to say otherwise. The home is extermely "tight" in infiltration rates, and the R-values are exceptional. I am concerned about the lack of thermal mass of the warmboard and its ability to condensate when in cooling mode.
I have decided to install two whole house dehumidifiers on the the two HRV's that provide mechanical ventilation for the first and second floor, seperately. Lucky for me I am also installing a complete forced air cooling system as a means of second stage cooling should there be any problems with the radiant cooling. And from what I have read, homeowners tend to be problematic when controlling radiant cooling floors since they like to open windows.
I have designed one radiant floor cooling system with water to water heat pumps and one water to air heat pump for de-humidification. That system works exceptionally well, granted it has a $30,000 dollar control system installed. I do not have that kind of budget.
Finally, the last hurdle to cross on this project is the fact that my heat pumps are DX and not water source. Let me tell you, DX heat pumps are not control friendly when you distance yourself from the simple forced air heating and cooling.
That is all from me today. I hope to hear some thoughts on the matter as your input is always appreciated.
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