Using a dehumidifier for space cooling and heating
Residual effects of the dehumidifier’s refrigeration circuit can also be used to cool and partially heat the pool area. The dehumidification process cools the air to condense moisture; during the cooling season this cool dehumidified air can provide year-round comfort without additional operating costs.
These systems can help to heat the space as well. Once again, this is accomplished by recovering heat generated by the compressors. If a pool space needs heating and the pool water heating requirement has already been satisfied, that same heat recovery can be used to partially or totally heat the space. On extremely cold winter days, the building’s conventional heating system will be required to maintain the set point temperatures for the space; however, the first stage is to use all of the heat the compressor generates.
Economizer mode
The economizer concept is not new in the HVAC industry either. Traditional HVAC systems with economizer modes use outdoor air to cool the indoor space. Indoor pool facilities, however, are a little more complicated as outdoor air is used to cool and control the space humidity levels simultaneously. For this to happen, the outdoor air needs to be mild and dry; therefore, the window of opportunity for this mode varies based on geographic locations.
The more humid the location, the fewer days this mode can be used. Larger systems often have a purge setting, which puts the system into 100 per cent outdoor air mode for a few minutes to remove the gaseous pool water chemicals out of the space. A system like this can provide economizer operation for no extra cost. If the outdoor conditions are right, setting the dehumidification equipment to the economizer mode results in free cooling and humidity control. The unit’s microprocessor controller normally monitors the outdoor and indoor conditions and will activate this mode automatically when conditions permit.
LEED and green advantages
For new construction projects, a dehumidifier with many of the aforementioned energy reduction advantages can deliver significant credits in the Leadership in Environmental and Energy Design (LEED®) program. Additionally, there are possibilities of receiving government incentives and utility rebates for strategies that reduce energy use.
Natatorium dehumidifiers offer more than just LEED credits for energy reduction, however. Water conservation is also a major consideration. Dehumidifiers generate significant amounts of condensate, which can be collected and returned to the pool, saving thousands of litres of water annually. The condensate is clean and nearly potable; yet, its acceptance varies according to local codes. At a minimum, this can be added to the ‘grey water’ reclaim. Condensate return strategies can often amount to one entire pool fill annually.
Additional LEED credits can be accumulated as a result of addressing IAQ measures such as high minimum efficiency reporting value (MERV) air filter materials and reduced refrigerant system charges.
