EcoRenovator - View Single Post - Hydronic Floor pump frequency vs water supply temp?

MN Renovator · 03-09-13, 01:41 PM

Don't get me wrong. I don't have much against radiant heat as a heat source. I'm not seeing your point about humidity or dust though.

Humidity control during a heating climate in a well sealed house is not needed but the most important part is that there is no difference between forced air and radiant heat in that respect. You don't remove or add moisture to the air in the enclosure with either method unless you install a humidifier or rehumidifier to the forced air system.

Dust control can't happen period without air movement, you need to pass the air through a filter to remove the dust. So I'm not sure where you were going with that either. Granted I'm not saying it's a big issue or anything, just trying to figure out where you were going there because a decent filter on a forced air system is going to clean the dust out of the air that passes through it. With the radiant system the dust will stay suspended in the air and precipitate out on surfaces and get kicked up by human activity. Either way you go it's probably better to avoid carpet versus making a decision over whether or not your heating system moves air.

With a low energy building you can centralize your heating and cooling and the entire structure will remain the same temperature. I've noticed that the further that temperatures deviate towards the outdoor temperature are the least insulated even to the point where I can block both return and supply vents from my most insulated room and have it warmer in that room than my least insulated room that has air flow. So you are right about not needing the hydronic floor plumbing everywhere if you are aiming for close to passive, or at least something around the R's of 5,10,20,40,60 with reduced glazing in the home design, although slab on grad you remove the R20 component and if going with R3ish energy star windows you'd need to reduce glazing to under 15% window to wall, IMHO. The only trouble you get into with that idea though is reduced ability to recover from large setbacks without either temperature differentials or long setback durations. I might be the only person with a 25 degree setback(for both away, sleeping, and often for entire 10 hour 4 day workweeks) though, oddly one that I'd probably want to keep even with a low energy building.

03-09-13, 01:41 PM	#22
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	Don't get me wrong. I don't have much against radiant heat as a heat source. I'm not seeing your point about humidity or dust though. Humidity control during a heating climate in a well sealed house is not needed but the most important part is that there is no difference between forced air and radiant heat in that respect. You don't remove or add moisture to the air in the enclosure with either method unless you install a humidifier or rehumidifier to the forced air system. Dust control can't happen period without air movement, you need to pass the air through a filter to remove the dust. So I'm not sure where you were going with that either. Granted I'm not saying it's a big issue or anything, just trying to figure out where you were going there because a decent filter on a forced air system is going to clean the dust out of the air that passes through it. With the radiant system the dust will stay suspended in the air and precipitate out on surfaces and get kicked up by human activity. Either way you go it's probably better to avoid carpet versus making a decision over whether or not your heating system moves air. With a low energy building you can centralize your heating and cooling and the entire structure will remain the same temperature. I've noticed that the further that temperatures deviate towards the outdoor temperature are the least insulated even to the point where I can block both return and supply vents from my most insulated room and have it warmer in that room than my least insulated room that has air flow. So you are right about not needing the hydronic floor plumbing everywhere if you are aiming for close to passive, or at least something around the R's of 5,10,20,40,60 with reduced glazing in the home design, although slab on grad you remove the R20 component and if going with R3ish energy star windows you'd need to reduce glazing to under 15% window to wall, IMHO. The only trouble you get into with that idea though is reduced ability to recover from large setbacks without either temperature differentials or long setback durations. I might be the only person with a 25 degree setback(for both away, sleeping, and often for entire 10 hour 4 day workweeks) though, oddly one that I'd probably want to keep even with a low energy building. Last edited by MN Renovator; 03-09-13 at 01:45 PM..