EcoRenovator - View Single Post - PEX for cooling sub-floor

randen · 07-09-13, 08:50 PM

I would caution the utilization of surfaces for cooling.

The main reason we feel uncomfortable as humans in warm humid weather as AC Hacker pointed out. Our natural cooling method of sweating is less efficient when humidity is high. Our sweat doesn't evaporate very well hence removing less to no heat from our skin.

Air conditioning like the name implies lowers the humidity making us feel more comfortable as the act of sweating becomes more efficient at removing heat from our skin. You can feel quite comfortable in dry 80Deg F room as opposed to a 80 Deg F. Humid room. With the same dry air at 72 Deg F. we can start to feel cold.

Having first hand experience with radiant floor heating it is extremely poor for air-conditioning or space cooling. As mentioned in an earlier post the condensation point is reached quite quickly with little comfort gained as the air remains humid, in-fact more clammy feeling. The surfaces will begin to sweat. I realize that we are able to control temperatures of the surfaces closely to stay out of the dew point but there will be areas close to the entry point of the cool water that hadn`t received the message yet and will begin to sweat. And don`t forget that dew point will change as the temperature & relative humidity changes and the surfaces temperature can`t change fast enough.

The real dangers with cooling surfaces such as ceilings or walls if no dehumidification is taking place is moisture on the surfaces will cause mold.

We find here at home if the concrete floor cools to less than 70 Deg.F with the cool air-conditioned air falling down on to the floor causes our feet to ache as the muscles become cold. If I wasn`t such a energy miser I would like to add just a wee bit of heat to the floor. I couldn`t imagine the discomfort with a cooled floor of 55-60 Deg F

The best solution is to pump the cold liquid through an air handler and properly remove the humidity and reduce the heat. The amount of cooling provided by a heat pump is amazing and very efficient.

The combination of dehumidification and surface cooling for a commercially huge building may offer some greater energy savings as large expansive concrete walls suck up huge amounts of heat. But for a residential home the double complex system isn't good ROI.

Randen

07-09-13, 08:50 PM	#10
randen Uber EcoRenovator Join Date: Apr 2011 Location: Strathroy Ontario Canada Posts: 657 Thanks: 9 Thanked 191 Times in 129 Posts	I would caution the utilization of surfaces for cooling. The main reason we feel uncomfortable as humans in warm humid weather as AC Hacker pointed out. Our natural cooling method of sweating is less efficient when humidity is high. Our sweat doesn't evaporate very well hence removing less to no heat from our skin. Air conditioning like the name implies lowers the humidity making us feel more comfortable as the act of sweating becomes more efficient at removing heat from our skin. You can feel quite comfortable in dry 80Deg F room as opposed to a 80 Deg F. Humid room. With the same dry air at 72 Deg F. we can start to feel cold. Having first hand experience with radiant floor heating it is extremely poor for air-conditioning or space cooling. As mentioned in an earlier post the condensation point is reached quite quickly with little comfort gained as the air remains humid, in-fact more clammy feeling. The surfaces will begin to sweat. I realize that we are able to control temperatures of the surfaces closely to stay out of the dew point but there will be areas close to the entry point of the cool water that hadn`t received the message yet and will begin to sweat. And don`t forget that dew point will change as the temperature & relative humidity changes and the surfaces temperature can`t change fast enough. The real dangers with cooling surfaces such as ceilings or walls if no dehumidification is taking place is moisture on the surfaces will cause mold. We find here at home if the concrete floor cools to less than 70 Deg.F with the cool air-conditioned air falling down on to the floor causes our feet to ache as the muscles become cold. If I wasn`t such a energy miser I would like to add just a wee bit of heat to the floor. I couldn`t imagine the discomfort with a cooled floor of 55-60 Deg F The best solution is to pump the cold liquid through an air handler and properly remove the humidity and reduce the heat. The amount of cooling provided by a heat pump is amazing and very efficient. The combination of dehumidification and surface cooling for a commercially huge building may offer some greater energy savings as large expansive concrete walls suck up huge amounts of heat. But for a residential home the double complex system isn't good ROI. Randen Last edited by randen; 07-09-13 at 08:53 PM..