The Experts Guide to Industry Terminology | CARSI Educational Material

A Helpful guide for beginners in Water Restoration.

Technicians and Office adminstrative teams

• RH – Rel­a­tive Humid­i­ty — Rel­a­tive Humid­i­ty refers to the mea­sure of how close the water vapour in the atmos­phere is to its sat­u­ra­tion lim­it. Essen­tial­ly, it tells us how much mois­ture the air can hold at a spe­cif­ic tem­per­a­ture. To put it sim­ply, rel­a­tive humid­i­ty does­n’t direct­ly indi­cate the amount of water vapour unless the tem­per­a­ture is con­sid­ered.  For begin­ners in the indus­try, under­stand­ing rel­a­tive humid­i­ty is cru­cial as it plays a sig­nif­i­cant role in var­i­ous aspects of Emer­gency Water Restora­tion. By know­ing the rel­a­tive humid­i­ty, we can gain insights into cor­rect dry­ing pro­ce­dures, the com­fort lev­el of human beings, and even dry­ing times. Remem­ber, the high­er the rel­a­tive humid­i­ty, the clos­er the air is to its sat­u­ra­tion point. This means that the air holds a sig­nif­i­cant amount of water vapour, mak­ing it feel humid and pos­si­bly lead­ing to con­den­sa­tion and re-wet­ting. On the oth­er hand, low­er rel­a­tive humid­i­ty indi­cates that the air has less water vapour, result­ing in dri­er con­di­tions. This could lead to a high­er risk of dehy­dra­tion, increased evap­o­ra­tion, and poten­tial chal­lenges for occu­pants and work­ing con­di­tions. So, as a begin­ner in the indus­try, it’s impor­tant to grasp the con­cept of rel­a­tive humid­i­ty and con­sid­er it when analysing restora­tion projects, plan­ning equip­ment instal­la­tion, or even adjust­ing the envi­ron­ment for opti­mal com­fort lev­els.

• Hydro­scop­ic Mate­ri­als — When it comes to build­ing mate­ri­als and micro­bial organ­isms, their response to rel­a­tive humid­i­ty (RH) is more impor­tant than the absolute water vapour con­tent. Sur­pris­ing­ly, even small amounts of water vapour at low tem­per­a­tures can raise the RH lev­els to 50–70%. This sus­tained high RH, occur­ring between tem­per­a­tures of approx­i­mate­ly 4 and 40°C, can pose health risks and poten­tial­ly dam­age the build­ing struc­ture before RH reach­es 100% (also known as the dew point) and con­den­sa­tion starts to occur.  Under­stand­ing the behav­ior of hydro­scop­ic mate­ri­als and the impact of RH on build­ing fab­ric is cru­cial, espe­cial­ly for begin­ners in the indus­try. By grasp­ing these con­cepts, you’ll be able to make informed deci­sions and nav­i­gate the chal­lenges effec­tive­ly.

• Absolute Water Vapour Con­tent — Absolute water vapour con­tent refers to the actu­al amount of mois­ture present in the air, mea­sured in grams of water vapour per cubic meter of air. Unlike rel­a­tive humid­i­ty, which is influ­enced by tem­per­a­ture, absolute humid­i­ty gives a straight­for­ward mea­sure­ment of mois­ture lev­els. This infor­ma­tion is par­tic­u­lar­ly use­ful for those new to the indus­try, as it helps begin­ners under­stand the basic con­cept of mois­ture in the air.
• Dew Point — The dew point is an impor­tant term in restora­tion that refers to the tem­per­a­ture at which the air becomes sat­u­rat­ed and can no longer hold any more water vapour.   Sim­ply put, when the dew point is low, such as around 50 — 60°F/10 — 15°C, the air feels com­fort­able and pleas­ant. It indi­cates that the air is not exces­sive­ly humid, mak­ing it eas­i­er for our bod­ies to cool through evap­o­ra­tion.