Earth Notes: On the HTC-1 Desktop Humidity and Temperature Meter: Review
- Neewer HTC-1 Digital LCD Humidity / Temperature / Clock desktop display
- Reviewed by: Damon Hart-Davis on 2012/11/13
- Clear display, accurate, cheap.
- This desktop humidity and temperature meter works well and is good value for money, and can be read across a room.
- Rating: out of 5
As we have improved the air-tightness of our house to reduce we have had a problem in winter with rising humidity and humidity and it's not just an effciency issue; local councillors confirm to me that often when they get complaints about 'damp' it's actually condensation from insufficient ventilation.
Building regulations are quite clear that heating energy efficiency must be good and ventilation must be improved and controlled to keep air 'fresh' which includes keeping down levels of CO2 (above 1000ppm is poor) and relative humidity (above 70%RH invites mould and mites to proliferate).
Thermometers are easy to come by and cheap and most of us have thermostats, but humidity and CO2 meters and regulation devices less so.
The MHRV (Mechanical Heat-Recovery Ventilation) in our bathroom both increases continuous ventilation while retaining heat, but it also has a humidity sensor and goes into boost most when humidity is very high, generally while during/after a shower or bath. So I have one device to help crudely manage humidity, but it is not enough.
My only humidity sensor with a readout was a piece of test equipment, Maplin N09AQ 4-in-1 Multi-Function Environment Meter, relatively expensive at ~£70 and not a continuous display. Also humidity sensors seem to work best if allowed to 'settle' for as much as an hour, so making simultaneous measurements at different points around the house difficult!
These cheap-n-cheerful Neewer HTC-1 devices, spotted on Amazon by my friend Martin F, seem amazingly good at about £4 each, with readings within 1°C and 1%RH of my test meter, easy enough for even my children to read, big enough to see across the room. At that price having a couple to leave in strategic places (eg kitchen and the living room or a bedroom) is fine.
As of 2012/11/13 we've only had these about six weeks, so longer-term robustness, battery life, etc, has yet to be established, though physically they seem reasonably well built as well as easy on the eye.
(As of 2017/07/26 both meters are still working, though on one the plastic clip to prop the device up on a horizontal surface broke some time ago.)
I aim to keep RH% (relative humidity) below 70%, and if a meter shows more, increasing ventilation where practical (eg not too cold outside) or deploying our portable dehumdifier, eg in the kitchen when drying clothes. This helps us target remedial actions accurately and efficiently, rather than just guessing.
(Given persistent high readings and knowing that we probably need to boost ventilation anyway, we're adding another MHRV in the kitchen in the hope that with one there and in the bathroom, most of the moisture entering the house will be efficiently eliminated at source, avoiding its spread elsewhere.)
IMO: The most important things to do to ensure reasonable humidity and fresh air in a house:
- Ventilate (and check the fans every now and again, at least whether they'll hold a square of toilet paper on boost)
- Heat: both to evaporate moisture and increase the capacity of the air to hold moisture. This means that the cold air outside (wintertime) usually holds less absolute moisture than the warm air in your house so when it's brought inside and it mixes with the warm house air, it warms and the relative humidity inside falls. There's a common mistake made when people open the windows and turn the heating off and expect it to dry out.
- Find and remediate particularly cold surfaces, thermal bridges, poor insulation, blown windows etc. Radiators under Windows in older properties (and on) are usually a good idea to ensure there's not a particularly cold surface that warm moist air will find & condensate on. Plus it aids in mixing air and preventing drafts. On modern or well renovated properties such as Damons this isn't as critical.
- Locate and remediate any sources of water ingress such as damaged waterproofing, dodgy gutters etc.